Difference Between Spar Varnish and Regular Varnish?

This article was inspired by a question from K Sanchez who writes: “What is the the difference between spar varnish and regular varnish?”

Why We Need Outdoor Formulations

Before we dig into the details, let’s talk about why we need a different varnish for outdoor applications. Any wood stored outside is going to be exposed to a wide range of temperatures and weather, as well as a good dose of damaging UV rays. These elements serve to break down the finish over time. Furthermore, changes in humidity cause the wood to expand and contract, and a standard indoor finish would simply crack and deteriorate under these conditions. Spar varnishes are typically designed to not only protect the wood, but also give it the flexibility and UV protection it needs to last for years. And the name “spar varnish” comes from the boating world, where the long wooden poles that support the sails are know as spars. So a spar varnish needs to be one that can withstand the rigorous conditions of seafaring life.

The Components

Nearly all modern varnish contains a few basic components: oil, resin, and a solvent. By modifying the types and amounts of these components, we can create a whole range of mixtures that vary in price and are specifically suited for either indoor or outdoor use. Fortunately for the inquisitive finisher, there are only so many ingredients that manufacturers have to choose from. And this makes it easier to see beyond the marketing jargon to deduce how a particular finish will behave. Here are the most common recipe ingredients:

Oils – Linseed Oil or Tung Oil
Resins – Alkyd, Phenolic, or Polyurethane
Solvents – Mineral Spirits, Naptha, or Paint Thinner

Oil to Resin Ratio

When a varnish is made, the ratio of oil to resin can have a dramatic effect on the way the varnish will behave. For instance, using a small amount of oil and a large amount of resin will produce a very hard but somewhat brittle finish. Obviously, this is not suitable for outdoor applications since we need an outdoor finish to be flexible. So what makes more sense is to create what is known as a “long-oil varnish”, that is, a formulation that contains a greater percentage of oil. The extra oil results in a softer, more flexible finish that will not crack when the wood expands and contracts.

Oil Types

The most common oil used to make varnish is linseed oil. Its lower cost makes it the most practical choice for both indoor and outdoor formulations. But many believe that tung oil is actually better for outdoor use. After all, a higher quality oil should equate to a higher quality varnish, and thus a higher price tag. As a result, many of the high-end marine varnishes will be made with tung oil instead of linseed oil.

Resin Types

Generally speaking, phenolic resins are best-suited for outdoor use. But that doesn’t mean every spar varnish is made with phenolic resins. Much like the situation with oils, the better product is also the most expensive. So you’ll find plenty of outdoor formulations using alkyd and urethane resins. A popular finish like Helmsman Spar Urethane contains urethane modified alkyd resins. A higher quality finish like Epifanes contains phenolic modified alkyd resins. There are many other brands of outdoor oil-based varnish, but the ingredients list is usually much more revealing than the words on the front of the can.

Sun Block For Wood

Most spar/marine varnishes will contain other important additives, such as UV blockers, that give the wood that extra bit of protection it needs in harsh conditions. UV light will not only damage the wood, but also the finish itself, eventually resulting in finish failure. So its a good idea to use a finish containing UV-blockers for any outdoor project.

Conclusion

Generally-speaking, my preferred outdoor varnish would be a long-oil varnish made with tung oil and at least some phenolic resins and UV inhibitors. And most times the brand I reach for is Epifanes.

If you’d like to learn a little more about how I apply varnish, check out this article: A Better Way to Apply Spar Urethane

If you want to learn more about my favorite finishing method, you should check out my DVD, A Simple Varnish Finish. My goal with the DVD was to demystify finishing by going over each and every step of the wiping varnish process. Even someone new to the world of finishing can create a show-stopping finish if they follow the methods outlined in the DVD. So check it out!

Category: Finishing

Comments

  1. Michael Morton October 20, 2008

    Thanks for the very detailed response, compacted into just a few paragraphs. Really taking the mystery out of it all.

  2. Denny October 20, 2008

    Hi Marc,
    I looked up “Epifanes” on the net and found out it’s a manufacturer’s name that makes several coating products. When you mention Epifanes which product are you referring to? I think I’ve narrowed it down to two: Epifanes Clear Varnish or Epifanes Woodfinish Gloss/Matte. (Jamestown Distributors carries both products so that didn’t help me reduce the possibilities.)

  3.  

    The product I use is Epifanes Clear Varnish.

  4. Germain October 20, 2008

    Good info, Marc.

    Now, when are you going to post video from your David Marks visit? :-)

  5.  

    haha. unfortunately, I think you are going to have to wait quite a while for that.

  6. Germain October 20, 2008

    Well, major bummer. Since DIY stopped showing “Wood Works”, I’m really going to be missing DJ Marks.

  7.  

    Stopped showing Woodworks?!?!? Have they gone mad??!?!?

  8. Claude Stewart October 21, 2008

    I like David Marks stuff as much as anything I’ve seen but Woodworks has been in reruns for how many years now. I don’t know about everybody else but I get tired of watching him build the same thing over an over. I actually took it off my to do list on my dvr and then after a year or more put it back on and it was still just reruns. I just think that he didn’t want to continue with the show and moved on to different things. Claude

  9. Claude Stewart October 21, 2008

    Oh and Marc, Leo Laporte is doing the the Gadget station on The Daily GizWiz today on turn the table tuesday. Claude

  10. Allen Lindsey (AlleninOH) October 21, 2008

    They’ve really cut back their woodworking content over the past couple of weeks. Until recently the DVR would pick up usually 4-5 episodes of both New Yankee Workshop and Woodworks, granted they were the same episodes over and over a lot of the time, but now there’s one ep of NYW a week, no Woodworks at all. Of course you can still see “Hammered” with Jimmy and John DiResta, which is horrible. I’ve only managed to make it through two episodes before I gave up on that one. It was the beginning of the end for me when I saw one of them clamp a router upside down in a vise and use it like a table mounted router. Shudder…

    One of my local PBS stations has started running The Woodsmith Shop but them, and Scott Phillips’ show (Pocket screws and Gorilla Glue! Yay!) are a poor substitute and the other PBS station is re-running Norm’s endless kitchen cabinet series right now. Bleah.

  11.  

    I stopped watching a long time ago because I had seen all the episodes so I totally understand. But there are lots of new woodworkers out there who haven’t seen all the episodes. And having WoodWorks on there at least gave people an opportunity to see some quality woodworking programming. From the sounds of it, there’s nothing left….. Very sad.

  12. Christopher Schwarz October 21, 2008

    Good post!

    A note on spar: Bob Flexner has stated several times that household spar varnishes typically have very little in the way of UV inhibitors. Manufacturers will typically just a few drops of the inhibitors to a vat of finish. And so their resistance to UV is not much better than regular varnish.

    Marine varnishes, which are far more expensive, do contain considerable amounts of UV inhibitors. So if you need UV protection, you might want to head to boat shop….

    Chris

  13. Germain October 21, 2008

    As I understand it, the Epiphanes Marc recommended is in fact a marine varnish. Am I correct on this?

    As for woodworking shows, I’m a relatively new woodworker and I learn something every time I watch Wood Works and New Yankee Workshop. Each show presents different styles and techniques, which I lke.

    All the other DIY shows make me feel like I’m a “Master Carpenter”. ;-)

  14.  

    That’s correct Germain. Epifanes is a high quality marine varnish. My personal favorite for outdoor applications.

  15. Richard October 22, 2008

    Folks,
    A favorite subject since I have a boat and a home, both with brightwork and natural wood trim that gets hammered in intense sun. I re-coat it with spar varnish every 6-8 months. I seem to get a longer lasting application if I put a bit of stain in the spar varnish, as well as a bit of Penetrol. But the re-finish time comes around pretty fast.
    I had a friend years ago that used what I supposed was a clear linear polyurethane wood ‘varnish’ on his boat’s brightwork, and he claimed it was a 10 year coating. I lost track of him and never have been able to find out what product he used.
    I have also had people recommend Sikins (sp?) which I think is an oil, not a varnish, and might require stripping all the old finish off. Also it is used mostly on siding, and may not be a good product on brightwork that must resist abrasion and get reasonably hard within a couple of days..
    Maybe we could all benefit from re-finding out what the best long-life product might be.
    Great site, by the way!
    Thanks,
    Richard

  16. Richard (http://) October 22, 2008

    David “retired” from PBS in 2001 so all shows are reruns.
    Norm had a new series on kitchen cabinets recently that has a lot of good stuff, otherwise his shows are also reruns
    but all these shows have something worthwhile for the new and not so new woodworker IMHO
    Richard

  17. Jeanie Lively November 9, 2008

    I want to put finish on an old pine floor that as never had a finish on it, but would like it to be durable as far as not scratching etc. I have a formula that would consist of equal parts of boiled linseed oil,good turpentine,and gloss varnish. Would this be something you would recommend over a polyurethane?

  18.  

    Hi Jeanie. I am curious why this is going over a polyurethane. You said the door doesn’t have a finish on it yet. If that’s the case, I would just start applying your oil/varnish blend. Now if for some reason there is already poly on the door, the oil/varnish blend might not be the best option, because the wood is already sealed. Once that happens, the oil in your oil/varnish mix tends to stay tacky forever. So if you are coating over top of poly, I would sand the surface thoroughly to rough it up, then apply coats of the varnish/turp mix (no oil).

  19. Jeanie Lively November 10, 2008

    Thank you very much for your response. I am sorry that I did not make myself very clear. The oil varnish formula would be going on a floor that has never had a finish on it. My question is would this be better to use verses a polyurethane finish? This is a very old pine floor, and I would like a finish that would be durable to scratching etc. Thanks, Jeanie

  20.  

    Ahh, i see now. I also realize that I mistook “floor” and “door”, lol. My brain has been in another place this week with the website changes. Anyway.

    The polyurethane would definitely be the best choice for the floor. Oil/varnish blends are nice one furniture and medium to low-wear projects. But the oil content in the mix results in a finish that is a little softer and doesn’t quite build as quickly or as thick as you would want on a floor. So without a doubt, I would recommend a full-strength polyurethane.

  21. Alex December 3, 2008

    Hi WoodWhisperer,
    My question is about coating my bay window sill. I used a recommended varathane I think it was called and after a year the plants my wife put on the sill have left a bit of a mark. I even put the plastic spill catcher under them, but I think there must have been some spillage that went unnoticed. I was going to sand it as best I could and re-apply a better product to save it from the same fate. I was going to put down a marine varnish to keep the water from damaging it again. Any recommendations?

  22.  

    Hey Alex. My favorite marine varnish is Epifanes. Probably a good option for your application. But keep in mind, no finish will withstand repeat exposure to moisture like that. The real solution is to protect the surface with some kind of barrier to the moisture, like a coaster on a coffee table.

  23. Larry June 18, 2009

    I’m building a plywood boat. I’ve used epoxy and am told I need to finish it with Marine Varnish. A trip to my local West Marine shows that theirs is $35 a quart. Any less expensive ideas?

  24. Ted July 3, 2009

    I had a cedar deck and gazebo put in 2 years ago and gave it one coat of Sikkens SDR as it was less than 2 feet high in spots. The SDR on the horizontal surfaces exposed to sun and snow turned gray and started to crack this year so I resanded and reapplied the SDR. I would like to put something stronger that would last longer than 2 years. Are there marine products available in Canada that I could use that would not be too shiny? Thank you for your help.

  25. Judy B September 4, 2010

    I had a new front door installed last winter, and it has an oak sill. the carpenter put 2 coats of polyeurethane on it before it was installed, but the horns were cut in place… so had no finish.

    now 8 months later, the poly has worn off from water exposure on the edge…and there is a slight amount of splitting at the ends…

    What’s my best course of action now…

    •  
      thewoodwhisperer September 4, 2010

      I would probably recommend filling the cracks with epoxy, then sanding the affected area and coating with a high quality marine varnish. That should help prevent further splitting.

      • Judy B September 4, 2010

        Can you suggest an epoxy for me…

        and do i need to sand the entire threshold down to bare wood or just rough it up where the finish is not holding up…

        •  
          thewoodwhisperer September 4, 2010

          Any epoxy from the home store will do the trick. And if you want everything to look consistent, its a good idea to sand everything consistently. If not, you could wind up with some variability between the old and new finish. But if the appearance isn’t a huge issue, you can probably get away with lightly sanding the entire area and coating it with the varnish.

  26. Judy B September 6, 2010

    I am pretty sure that the wood they used for the threshold is red oak, and I am hearing that it is not good for exterior use. Any easy way to confirm if it it red oak or white?

    and if it is red oak, same suggestions, epoxy cracks, sand it and polyeurethane it… or spar varnish it…

    someone also told me to use chemical stripper first, then sand, then oxalic acid to remove any discoloration…
    welcome your thoughts…
    thanks,

    •  
      thewoodwhisperer September 6, 2010

      I agree that it probably is red oak. At this point, I don’t know of any easy way to determine if its red or white. And that probably won’t change what you do to treat it so its a bit of a moot point. That is unless you plan to gut it and replace it. So yes, same treatment as before.

      Now a stripper isn’t a bad idea at all. But it depends on how much work you want to put into it. The best thing to do in my opinion would be a full strip and sanding. Get the entire thing down to bare wood for the best consistency. Only use oxalic acid if you have discoloration to deal with. Then repair with the epoxy, sand everything smooth again, and apply the topcoat.

  27. Christian January 29, 2011

    G’day from Australia,
    Thankyou for your website.
    You mentioned the three components for a DIY spar varnish (Oil, Resin and Solvent), but did not recommend the quantities of each.

    Could you please advise.
    I am looking for a “recipe”.

    Thanks again,
    Christian

  28. Help! Have a horse barn that I just put an addition on. I have five stalls that I stained and need to finish with urethane or varnish.The original stalls were stained with minwax cherry stain, then 2-3 coats of Helmsman semi gloss spar urethane was applied. This was done about 8 years ago. The urethane has yellowed some and faded in areas, particularly on the stall fronts at the ends of the barn that get direct sun. Have been reading about spar urethane and spar varnish and don’t know which way to go. It sounds like a good quality varnish might be a better way to go. Sounds like there are also some better products out there than the Helmsman spar urethane. Obviously, epifanes is too exspensive for such a large area. Jamestown has a product called Circa 1850 Exterior varnish marine grade at $48.45 per gallon. Would that be a good product to use? Can you recommend a product?. Also, I sanded down one of the old stall doors and restained it, it looks good but came out a little darker than before, I guess since the wood is older. Can I put a varnish over this even though a urethane was on it before? Will varnish yellow over time like the urethane? Would like to refinish the old stall fronts and seal the wood on the new stalls. Thank you for any advice you might have.

    •  

      Hi Karen. Most of the projects I work with are on a smaller scale, so the products I use reflect that. I don’t really have much experience less expensive outdoor finishes that are made for covering large areas. So I can’t really comment on the Circa 1850 product. But its probably worth trying out, since if its meant for boats, it should probably work well on a stall.

      I am glad to hear you sanded the doors down. Its a good idea to completely remove the old finish either by stripping or sanding, and then reapply your stain and your new finish. There should be no compatibility issues at this stage.

      And just to clear up some terminology, I consider “Varnish” to be a large category of finishing, which includes polyurethane. Polyurethane is a type of resin so you could technically call it polyurethane varnish.

      So yes, pretty much ANY varnish will yellow over time. Its the nature of an oil-based product.

  29. Elaine March 4, 2011

    Hello –
    Southern California patio — lots of rain this year.
    Bamboo bar and chairs now with black gunk ?mold?
    I will strip off clear coating and clean.
    Do you recommend Epifanes Clear Varnish?
    It is not realistic for me to move the bar in when it rains, so far much rain. I will obtain some sort of cover in the future, yet it will be exposed to moisture from time to time.
    Bottom line — need water/mold/moisture protection.
    Thanks for your expertise!!

  30. Elaine March 5, 2011

    BIG THANKS! You’re the BEST!

  31. mrs.m April 6, 2011

    Hi,

    I’m installing new board and batton shutters on my house. 3 sets are 50″ by 14″ and 1 set is 66″ by 14″. I’m using 1x 4s and a 23 gauge brad nailer to assemble. I want them painted white and sealed. The 2 options of wood are pressure treated and not. I was told that the pressure treated needs at least a year to cure before paint could be applied. My conundrum is that I don’t want to hang the shutters unfinished for a year on my house. I would like to use the plain 1 x 4’s and properly seal them without yellowing.

    Advice on that process using the unfinished 1 x 4’s or is there a way to paint the pressure treated shutters sooner than a year? (like 6 weeks)

    thank you

    •  

      Hi Mrs. M. You touched on two things I don’t know a whole lot about: pressure treated wood and paint. These are materials I just don’t work with since most of my furniture is for interior use. So I would follow the advice of the pros. From what I read, some folks recommend a long wait before painting and others say you can simply wash the board with soap, water and a scrub brush, let it dry for a few weeks, then proceed with the painting. Since most of the lumber you buy at the home center is loaded with moisture, its probably a good idea to wait a few months anyway, just to let the excess moisture dissipate.

      If you decide to use regular untreated boards, I would recommend a high quality exterior primer and paint. Your water-based formulations should not yellow over time. Or at least, not as much as an oil-based paint would.

      Sorry I couldn’t be more helpful.

  32. Gayle June 17, 2011

    I have a beautiful custom designed/painted bench which sits outdoors. It was coated with some type of varnish which is now yellowed and peeling. I would like to remove the varnish without hurting the custom paint scene underneath as I am no where near talented enough to redo it. Can anyone suggest the best method to accomplish this. And the best method of putting varnish or other finish as an overcoat back on it that would not yellow?

    •  

      Hi Gayle. That’s going to be a very tricky endeavor. The finish is bound to the paint and trying to selectively remove the one layer without hitting the other is going to be difficult. One option would be to carefully scrape and sand the finish until you start to approach the paint layer. This is going to take time and patience. And if the surface is unlevel, you will likely sand all the way through in some areas but not in others. So you’ll have to move around a bit and selective sand certain areas to keep things even.

      Now if you should be able to get all the varnish off without damaging the paint, you’re best bet is to get away from oil-based finishes all together. They all yellow over time. Instead, switch to a water-based outdoor finish like General Finishes 450. But keep in mind that water-based finishes are not the most durable for outdoor use. But if you want a finish that won’t yellow, there aren’t many other options out there.

  33. Travis July 8, 2011

    Hello- I have some doors I need to finish. I’ve purchased two types of Spar Varnish. Cabot which is an oil and Varathane (Rustoelum Product) which is water based. I did the thresholds in the Cabot but after reading all the stuff here I’m wondering which I should used for the doors. Only one of the three doors gets hammered with hard late afternoon sun and heat. Recommendations? My compliments to your site here Its a terrific wealth of information. I’m glad google had it in the top 5 line items!!!!

  34. Mike July 22, 2011

    I have just finished up the construction of a new home and went with 8″ D-Shaped siding in a medium oak stain. I absolutely love the look and want to be sure I preserve it, as well as the wrap-around porch posts (8″x8″ rough sawn) and railings. Would the Epifanes CV1000 do the trick for me or is there another product that would be better suited to wood siding that I have already stained?

  35. Mark Roberts July 27, 2011

    Hi Mr. Whisper,

    What is the acronym for the list of ingredients for a product? For example, I have used Formby’s Tung Oil Finish for years with great results, which I know is just a wiping varnish, and I was wondering how it compared to the Arm R Seal you use on your projects. Does one have more solids, or different solids, than the other?

    I’m about to refinish a late 18th century mahogany table with single board sections; it is very dense and heavy mahogany. One thing I LOVE about a varnish finish (which I rub out with pumice and then rottenstone followed by wax) is that it is so durable; I love to entertain and never use a tablecloth, and as long as I pick up glasses after the last guest leaves, I never have marks on my existing table.

    Watching your videos had made me wonder if the Arm R Seal or Behlen’s Rock Hard Varnish is better (i.e. more solids).

    So what is the acronym for the list of materials in a product?

    Thanks; love your site!

    •  

      I am sure both Formby’s and Arm-R-Seal each have proprietary mixes of resins but to you and me, they are probably very similar in usage and appearance. Now Behlen’s Rock Hard is indeed a different formulation or at least different enough to notice. They do specifically boast a higher solids count making the finish more durable. Now truthfully, Arm-R-Seal has never let me down and I have never thought, “Boy I could sure use more solids!” But if I were making a bar top or some sort of surface that I know was going to take a beating, something like Behlens certainly might be worth trying.
      And I couldn’t agree more with your logic about using a high quality varnish finish.
      As for the acronym, that would be an MSDS. Material Safety Data Sheet.

  36. todd July 30, 2011

    I have built stairs and seating benches out of redwood for my outside deck. Living in Utah we have huge changes in weather from 100 degrees summer days to snow all winter. My deck faces east and is in the sun until early afternoon. I love the look of oil but want the benches to be useable and fear some ruined pants with using oil. I prefer clear finishes and wanted to know your thoughts on using Epifanes or something else you would suggest.

    •  

      As long as you use a finishing oil that actually cures (most of them do), there won’t be any concern about something coming off onto clothing. The drawback though is that you’ll be applying it more often over the lifetime of the deck. Epifanes is definitely protective enough, but you need to be sure you like the look. One compromise is to only add a coat or two of Epifanes so it doesn’t build to a thick film. It won’t be as protective, but its a nice compromise.

  37. Eric August 14, 2011

    Hello, I am interested in your advice concerning the finishing of an exterior fiberglass door. I will be using an Old Masters gel stain. I need some advice as to how to procede with a spar varnish product to provide a protective finish. I have read about your support of Epifanes and any advice concerning the use and application would be appreciated. Do I lightly sand between coats? High gloss first followed by a final semi gloss? Thinning 50/50 for each coat? I read about your rag application process as opposed to applying with a brush. Thanks for your assistance!

    •  

      For folks who are fairly new to finishing and want precise control over the final thickness of finish, I recommend diluting by 50% with mineral spirits and wiping. If you already know you want a fairly thick finish, then you should consider using a brush. It will build much faster that way. But I don’t usually like a real thick film so 3-4 coats wiped on is usually a good compromise for me. And I would only sand after the second coat and every coat thereafter. Sand very lightly with 320 grit or higher just to knock down any surface nubs.

      • Eric August 14, 2011

        Thanks for your advice! How would you finish with regards to gloss. I’ve seen some remark that cloudiness occurs when using multiple coats of satin. I plan on using the Epifanes clear varnish which is a high gloss and I’m not sure I want such a high lustre finish. Any technique suggestions?

        •  

          Well you can either build your coats with gloss and finish with a satin or semi-gloss, as you indicated, or you can abrade the gloss surface with either high grit sandpaper or steel wool to achieve a semi-gloss or satin effect. The abrasion method is quite nice because it also smooths the surface beautifully. So you might want to do a little research into “rubbing out a finish” just so you know your options. My favorite way to do it is using Festool’s Platin abrasive pads lubricated with some mineral spirits. I highly recommend doing a test board first though just to makes sure you like the way this method looks.

  38. Joan September 18, 2011

    I just bought Amish oak/hickory rocking chairs that have been finished with a polyurethane. I will be using the chairs outside on a terrace that is not covered. What can I do to better protect these chairs from the elements?

  39. Joan September 18, 2011

    Can the marine varnish be applied directly on top of the polyurethane or do the chairs have to be treated some way first to “rough up” the finish so the varnish adheres? If so, what is the best approach? Can you recommend a good marine varnish?

    •  

      Assuming there is no wax on the surface, you can simply sand the surface lightly with 220 grit paper and then wipe away the dust with a clean rag soaked in mineral spirits. The marine varnish I recommend is the one I mentioned in this article.

  40. Larry Neighbors September 19, 2011

    I am looking for a good finish for a water wheel. This water wheel is used in a fish pond, and I am worried about the varnish being toxic to the fish. Any help you can give me would be appreciated.
    Thanks.
    Larry.

    •  

      Hey Larry. Unfortunately, I’m not really qualified to comment on something like that. Having kept tropical fish in the past, I know how sensitive they can be so I am not prepared to even make a recommendation for a finish that would survive those conditions, while being safe for your finish.

  41. Helen November 10, 2011

    All I want to do is put a varnish on an interior window sill that is above a kitchen sink. It gets splashed with water on occassion. I want something that will ward off the water. What should I use??? I was going to use the Minwax Helmsman Semigloss Spar Urethane.
    What is your suggestion???

  42. carrie January 3, 2012

    we are building a teardrop trailer and would like to have a stained wood finish for the side walls (the top will be covered with aluminum). do you recommend using a marine varnish to weather proof and protect the hardwood plywood that the side walls are made from? what is the most affordable option?
    thanks

    •  

      Yes I do think marine varnish is a good option, but there are certainly more cost effective options. Hard to say if they will be “as good” but they should work quite well. Perhaps consider products intended for houses or decks, as these come in larger quantities at a decent price.

  43. Greg January 31, 2012

    Hey I am building a walnut and maple tray and tested out some spar varathane since it will be out in the sun sometimes and will have sweating drinks. I dont like the yellowish color the spar varathane turns the walnut but I tries out some minwax polyurethane on the walnut and like the natural color it gave me more. My question is am I able to apply like 3 coats of polyurethane and one spar varathane (for sun/water resistance). And then rub out the finish for a satin finish. Or should I just apply all polyurethane and then some paste wax (. Will that be able to resists some sun and sweating drinks?

    Thanks alot, Greg

    •  

      Hi Greg. If you don’t like the color of the spar varathane, I’d say skip it all together. Even put on as a final coat, you’ll still get some of the color you don’t really like. Even regular interior polyurethane has good water resistance so I would say just stick with one simple finish and call it done. If you want to apply wax, you certainly can but it really doesn’t offer much in the way of protection.

  44. Greg February 2, 2012

    Hey I was wondering what your favourite varnish brand is? I am looking for a finish that will give me a very clear look (non yellowing) an oil varnish, and one that will resist water fairly good. I am simply wondering what brand. (polyurethane, varathane, etc..)

    Thanks, Greg

  45. Jay Lebrun February 12, 2012

    I am building a 4′ x 3′ bar top for a customer of mine. The bar top will be outdoors and since I normally build indoor furniture, I need some advice. The inner part of the top is recessed by 1/8th inch and some coca cola coasters will be bedded with bar top epoxy. I understand that epoxy doesn’t do well outdoors. I plan on using a spar varnish over the whole project to protect it. I don’t want the epoxy to yellow so I am guessing this is the best way. I know the spar varnish will change the look of the clear epoxy but this is something the customer will have to deal with. Is this my best bet or do you have any recommendations?

    •  

      Well I don’t really do thick poured finishes so my experience in this area is very limited. But with a protective layer of spar varnish over it, I am sure it will endure quite a bit of abuse. Ultimately, any finish at that thickness is probably going to yellow to some extent over time. But if you want that type of finish, you don’t have many options. So I do think that’s your best bet.

  46. Roy May 24, 2012

    I build cornhole, a.k.a bag toss, corn toss… boards. I use birch plywood and either paint with exterior semi-gloss paint or stain. The boards get a pretty good bit of abuse so I need to put something durable over them. I have tried oil polyurethane and they were too slick. I bought some Old Masters exterior water based satin spar… but I think these are going to be too slick as well. Any suggestions on how to prevent this? We sell these things for $200+ and this is not a good thing.
    Thanks

    •  

      Well just about anything that produces a film will be slick. You can intentionally rough up the surface with some sandpaper, which will give you a matte look but a surface that isn’t quite so slippery. that might be my first suggestion. A second option would be to seal the board with a product called CPES (Clear Penetrating Epoxy Sealer). It is essentially a thinned epoxy that absorbs into the wood fibers and seals them quite nicely. A coat or two of this stuff, without sanding, should give you a pretty textured surface too. Hope that helps.

      • Roy May 25, 2012

        Thank you sir.

  47. Kasey Gilliss June 24, 2012

    Can you tint the Spar Varnish or can you buy it with different tints?

    •  

      There are varnish products with color in them, but it’s not my favorite way to add color. I find it a little difficult to control and i don’t think it looks all that good. I prefer to put color into the wood, and then protect it with a clear coat.

  48. Eric July 30, 2012

    The epifanes can (thanks for the recommendation) says to apply 4-6 extra coats barely thinned with 5-10% mineral spirits after I get the 3 main base coats on. I’m working on a door with full sun exposure. Do you recommend going all the way with the total of 7-9 total coats? I’m a novice. I like a shiny door & prep work was killer so I don’t want to do this door again. Is there such thing as too many coats?

    •  

      If you don’t mind a thick shiny finish, then I would follow the directions on the can for the most durable surface possible. And I suppose we all have our personal thoughts on “too many coats”. But I think it’s more of a diminishing returns thing. At a certain point, adding more coats doesn’t improve performance.

  49. j9 July 31, 2012

    Hi…read thru posts but didn’t find answers to what need….I just sanded 2 7ft rocky mtn pine beetle kill benches for outdoor use in Denver. Love the white and grey look so looking for a clear matte look to keep true color. Would I still use Epifanes or does this have an amber color to the clear? I have also read about another spar varnish called Penofin…any advice will be much appreciated! Also, I heard pine sucks up a lot of varnish so do you recommend using a pre conditioner like the Cold CPES epoxy?
    Thxxxx j9

  50. Mark Roberts August 4, 2012

    Hi,

    I am going to refinish an exterior mahogany door. I originally used spar varnish on it in 2004. I want to stain it darker, so I’m going to have to strip the existing varnish off.

    Also, the door gets the full western sun in Alabama. I know spar varnish has UV inhibitors. ARe there any stains that resist fading, too?

    Thanks

    •  

      You might look into using an exterior staining product. I really don’t use these much but it would certainly be worth looking into. Perhaps the stain itself will have UV inhibitors and other additives that will help the stain keep its color. Coupled with a high quality marine varnish, you should have a good solid finish that will last quite a while.

  51. Ryan August 6, 2012

    Hi Marc,

    I am in the process of building a folding table that will be subjected to moisture with great frequency. It is a beer pong table. But in all seriousness I like to do good work and I’m trying to make it look nice. It is made of clear redwood and I’ve been looking through a vast number of your very helpful tutorial videos for general finishing advice.

    My dilemma with choosing a finish is being caught between two conflicting interests. I desire hardness but also a little bit of UV protection. I now know that marine spar is softer to deal with the constant expansion and contraction of a boat’s life on the sea but has pretty darn good UV inhibition (granted it has a good number of coats). A normal oil varnish like a polyurethane for flooring can be hard but offers barely (if any) UV protection. I realize redwood is soft but it also does well outside which was a factor in my choice of using it.

    I would like to have something that is nice and hard with a little UV protection. I know you like the Epifanes but that seems like a pure marine spar (aka softer). Do you know of any coating, perhaps a marine deck varnish, that would address both of these needs?

    Thanks

  52. Ryan August 9, 2012

    Marc,

    Thanks for the response! I’ve been researching and I believe I’m pretty set on a certain brand of epoxy finish. It is called Max CLR HP and has a nice solids content. Not too worried about the uv anymore (decided it would be interior only) but I could also put an exterior poly on if need be. Any opinion on epoxy finishes?

    Thanks,
    Ryan

  53. Mike October 14, 2012

    I have a 1965 Starcraft boat with mahogany veneer on it. To preserve it I used Johnson floor wax. This made it worse. I believe the veneer was coated originally with polyurethane. The coating is pretty worn down. I would like to put spar varnish on it but I cannot do a lot of sanding on the veneer. Is there a coating you would recommend. What would you recommend to do.
    Thanks,
    Mike

  54. David January 11, 2013

    I keep hearing a lot about ‘the paint manufacturers put UV blocker or inhibitors’ In their formulations. The research I have done has only turned up one inhibitor compound and that is pigment. Could you please expound on what other UV inhibitors can be added to varnish? Especially inhibitors that will be useful for a clearcoat application?

    Thanks..

    •  

      In addition to pigments, one additive I have seen used in clear finishes is Ethyl-vinyl acetate. For instance, Minwax (Helmsman) Spar Varnish shows 3% pigments and 1.6% Ethyl-vinyl acetate by weight. I don’t know if this is standard practice for all uv-protecting varnishes but that’s at least one example.

  55. Kathy January 14, 2013

    We’ve recently built a kitchen bar counter out of old, weathered pallet wood. It’s beautiful and rough, with spaces between the pieces that can catch crumbs. I would like to protect the wood (and us from splinters) without changing the color, adding gloss or creating a hard plastic feel. Someone recommended spar varnish. Is this the best option?

  56. Guido January 25, 2013

    I am planning a post fence of 5″ diam. Eucaliptus poles, and plan to treat these with bora care to avoid ground termites. Afterwards i am planning to varnish these with a non yellowing, glossy clear varnish. The poles are exposed to the elements, verydry heat and occasional heavy rain.. What do you recommend?

    •  

      I would probably go for what I like to call the “bulletproof” finish. A pre-coat of CPES (Clear Penetrating Epoxy Sealer) followed by as many coats as you want of Epifanes. This is a very protective film finish that should last a good long time. In all liklihood though, this finish will yellow a bit with time since the product is oil-based. If you really need non-yellowing, you might look into some water-based or outdoor deck specific products (which I am not too familiar with).

  57. Arlen April 21, 2013

    Hi, I have 22 exterior doors that bake in the Arizona sun. The door are made of fiberglass with a wood grain pattern molded into them. The were originally stained with a gel stain and varnished. The finish lasted 4 years. I had a professional refinish them and the job only lasted one season. The painters explanation was that VOC rules in Arizona only allowed him to use crappy varnish.

    Can I steel wool these doors, gel stain them and then use the Epifanes spar varnish on them?

    Thank you.

    •  

      As long as you prep the doors adequately, you should be able to apply more gel stain and then Epifanes. I’d be curious to hear how the Epifanes holds up.

      • arlen April 22, 2013

        I guess I will try it and let you know. Thanks again

  58. Andrew Levine April 21, 2013

    Hey Marc, does spar varnish provide any extra water-proofing over poly? I am looking for a good finish for some cherry coasters, which will obviously get wet from time to time. The coasters also have some CNCd images “engraved” into the tops, if that matters.

    Thanks!

    •  

      Spar varnishes are supposed to be more water-resistant than indoor polys. But I think that’s more related to the fact that the material is more flexible. So if the wood absorbs moisture, the finish will expand and contract with the wood and won’t crack. For something like coasters, personally, I’d go with a high solids varnish, something like Behlens Rock Hard.

  59. Jim April 23, 2013

    Hi Marc
    Have you ever used spar Varnish or any other varnish to seal tile grout. Or do you have any other long term solution.
    Thanks

    •  

      Oh that’s an interesting thought. No I haven’t and I’m not sure of the long term ramifications of something like that. You would think the grout sealer companies would have something decent on the market. Do those products not work to your liking?

  60. David Walker April 27, 2013

    Good day. I’m getting ready to install my exterior siding (1×6 t&g pine) and want to leave the wood clear but protected. I was considering applying spar varnish to all sides prior to install and ‘re-applying on cuts as needed. Do you concur with my plan or do you have other advice? Sincerely, Walker

    •  

      I am certainly no specialist in the area of siding, but I am sure a good quality spar varnish would indeed protect adequately. But how that affects long-term durability, re-coating, and appearance is not something I can really comment on.

  61. Thank you for the info you provide on your website!

    My problem: I refinished my Victorian interior woodwork with several coats of Ben Moore oil based sanding sealer. That is all I used and it looked great! See pics http://www.oldhouseguy.com/my_restoration . Now 15 years later the stain in the wood seems to be fading. I guess I should have applied a coat of varnish to protect it.

    Sadly today you can’t buy real oil based varnish anymore and I don’t think I should use a Poly. It seems that the only oil based non-poly is Man-O-War Spar varnish. I currently use this on my front door and window sills and never thought of using it on millwork or furniture. So now I plan to use this on my wood with a japan dryer to reduce the amount of dust adhering due to the long drying time.

    So – am I right so far? Please correct me if you have other ideas.

    Additionally since the stain seems to be fading I would like to tint the varnish. The Benjamin Moore guy said I could bring in a small container for some universal stain in Burnt Sienna which I must mix up. Do you think this would work?

    Your help is much appreciated!
    Ken

  62. Mike May 10, 2013

    I am building a solid bodied guitar.
    How does spar varnish rate in that application?
    Thanks,
    Mike

    •  

      I know many folks who use varnish on their musical instruments, so it should do quite well. But I’d look into some luthier forums if you want a little more detailed information on instrument finishes.

  63. Beth May 14, 2013

    Hi there, We are installing Ikea butcher block countertops in our (heavily used) kitchen. We are planning on using an undermount sink. In addition, our kiddos have been known to “not see” and leave spills on counters, [floors, furniture, carpet, the dog, etc.] indefinitely. We will not be cutting on the countertops. We are considering using marine spar for durability and ease of maintenance. Do you see any issues with this? What product(s) would you recommend that require little to no maintenance and offer superior moisture protection? Thank you so very much! We certainly appreciate your expertise and recommendations.

    •  

      Polyurethanes are a good way to go. Even something like Behlen’s Rock Hard Table Top Varnish is a good option. They should all repel moisture effectively. Of course long-standing spills can always cause issues, but that’s the drawback of wood countertops.

    • Bob July 2, 2013

      Beth,
      I realize I am seeing your question weeks after posting it but perhaps this will be helpful.
      If you are going to install butcher block countertops with the intention of using them for food preparation, then I would finish the surface with mineral oil. Personally, I don’t want to eat the resins in varnish after prepping salads and vegetables. The surface will dry out from time to time and you can just easily apply more mineral oil. If the surface gets stained or discolored, I often use a sharp cabinet scraper to scrap and clean the surface in preparation for more mineral oil. I suppose it could be sanded but the sharp cabinet scraper is the best tool.
      I hope this helps.
      Bob

      •  

        Not sure if you missed it Bob but she said that she doesn’t plan on cutting on the surface, which is why I went with the poly recommendation. If she were prepping food on the surface, I would have given different advice.

    • LL July 31, 2013

      Waterlox, a tung oil is what we are using on our Ikea butcher block, it comes highly recommended. Poly will give a good seal but the tung oil will penetrate all the way through. You have to let it dry completely between coats and fully cure for 7-9 days before using the surface so it is a hassle. You don’t have to mix it or sand between coats. On the other hand, with kids you may need to take a belt sander to it after a few years regardless of your choice!

  64. Justina Rae May 16, 2013

    Marc,
    I made a lovely bellrope recently. I used good old Man-O-War Spar Varnish to waterproof it and to UV protect the cotton rope.The next step is to add the decorative colors to it. Do you know what type of paint sticks best to spar varnish?
    Thank you!

  65. Don Sternick June 3, 2013

    Getting Ready to put a Walk in shower All Ceder would like to Waterproof do You have and Hints

  66. Gail June 4, 2013

    Recently, I painted two murals for the exterior wall of my employer’s courtyard. This will be exposed to harsh winter weather, hard winds and heat (being mounted on a metal-sided building). Because of this, I chose what I thought were the best-quality materials and paints for the job. I bought 3/4 inch marine-grade plyboard that won’t bend or peel or decompose over time. I put one coat of primer over it before painting the scenes with Sherwin Williams’ exterior latex paint (can’t remember the name of it but it’s very thick). Then, I put three thin coats of Helmsman Spar Varnish on it to protect it from the extreme weather conditions and sunlight. My questions are: did I use the right materials (I’m sure I did; but it’s my first outdoor murals) and can it be covered with a glass encasement without ruining the finish? (our maintenance man insists on it, but I don’t think it needs it).

    •  

      Hi Gail. This is a bit outside my wheelhouse. I don’t typically work with paint and I have no idea about the glass encasement. I can’t see why glass would harm anything though. And since the finish is already on there, you’ll just have to see how it pans out. I don’t feel that Helmsman is the best varnish for the job, but it’s a little late to change it. :)

  67. Vivian July 5, 2013

    Hi, I’m trying to find out if the spar varnish product comes in a matte finish? And if it does, where in Canada can I find it?
    Thanks.

  68. Alex July 17, 2013

    Thanks for writing such a clear and concise article. As an amateur, I have a much better handle of what I’m looking for thanks to this.

    Now comes the important question… Would spar varnish be a good option for finishing my bamboo bike? I need something that can provide a hard yet flexible clear coat (painted on, multiple layers, sanding in between), that bonds to bamboo, carbon fibre, and resin epoxy (west system 105 resin & 205 hardener).

    Someone pointed me in your direction and the local hardware stores think I am insane for asking for such a specific product… Help!

    •  

      Hey Alex. This is a bit outside my wheelhouse since I really only finish wood furniture. Not sure just how well a polyurethane varnish would adhere to those various materials. I’m guessing you might want a more industrial style finish, ideally. These are finishes that usually aren’t available to people like us primarily because they aren’t safe to work with unless you have proper ventilation and a spray booth.

      But if you do decide to try this, looking into marine varnishes as they are going to be higher quality than the spar varnish you can get at Home Depot.

  69. Peter Belt August 5, 2013

    My mother -in-law lives up in Eureka California and part of her exterior of the house is Ceder wood. She has it varnished but does not maintain it. How often should she re varnish the wood to keep it in pristine condition?

    •  

      Keep in mind I work on furniture for a living and that’s a very different beast than cedar siding on a home. I am not all that experienced in that area so my frame of reference is a bit off. I know folks who varnish their boats do it every couple of years.

  70. Sean August 8, 2013

    Marc,

    Very new to all of this, and I have some questions. I am in the process of finishing a cypress table for a ceramic grill. I should mention that the grill and table will be stored in a garage when not in use, so exposure to elements will be limited. Even with that said, I’d like to finish it off correctly just in case we decide to move it to the deck permanently.

    I decided to go with some Watco Danish Oil in Black Walnut and have put a couple of coats on thus far. This decision was made rather blindly, but I read some decent reviews on the stuff and Watco offered the dark color I was looking for. Based on what I’ve read on this site and others, I’m thinking that I should apply a few coats of spar vanish to finish the table. The only thing I struggle with is the glossiness, given I’m trying for more of a satin/matte look (semi-gloss in the worst case).

    What would you recommend here? Can I use Epifanes Clear Varnish for all coats and then sand with 0000 steel wool to accomplish this, or possibly the Clear Varnish with a final coat of the Woodfinish Matte product?

    Any help here is greatly appreciated.

    Thanks.

    Sean

    •  

      Well if the piece will be stored inside and you don’t like the look of a thick film, I see no reason to go with a thick varnish product. Stick with the danish oil or perhaps even try Watco Teak Oil. Their teak oil product is formulated with UV inhibitors and is well-suited for outdoor applications. Either way, you can always add a more protective finish later if need be. For now, I’d say use the stuff that gives the look you want.

  71. John August 21, 2013

    Hi Marc,
    I’m building a redwood deck in beautiful dry Utah….we are about 4500 feet elevation so we have standing snow in winter. What do you recommend to finish the redwood? My wife suggested spar varnish but in talking to someone from the lumber yard…he suggested the spar varnish would crack, flake, yellow and be hard to refinish. I like easy maintenance so…what would you use?

    •  

      Well, I’m not too familiar with finishing for that particular climate. This is one of those times when local advise might steer you in the best direction. If a film finish isn’t appropriate, what are other folks using? If you don’t go with a film, you’re looking at something that needs to be renewed routinely, which my not be the amount of work you want to do. So make some calls and ask around. Find out what works for others and make your decision based on that.

  72. Jen September 6, 2013

    Hi Marc,

    We had to tear out and rebuild the living room floor in our 1912 house. We’re putting in maritime pine flooring and would very much appreciate your advice on spar/ varnish. We have a very active dog and I’ve heard maritime spar varnish can protect against scratches. Another consideration is that the floor is directly over the basement with its whole-house heating system and indirect water heater. Though it doesn’t get a lot of sunlight, I anticipate a lot of heat changes. What would you recommend?

    Thanks in advance,
    Jen

  73. Korosh September 7, 2013

    Hi there,

    I’d appreciate your thoughts on Sapele? I live in Toronto and have Sapele windows that have weathered badly on the sill and need to be treated and varnished. Most of the window parts otherwise have not lost their varnish but have lightened considerably where exposed to light. Which spar varnish do you recommend and how many coats do I apply on the bad parts and not so bad ones? Also what daytime temprature would you think is too cold to work on the wood? Many thanks

    • Eric November 27, 2013

      Korosh – I am an architect, and have sapele wood windows in my home, I have tried several products on them for maintenance, and have found Sikkens Door and Window to be the best so far for a finish that lasts. Not the cheapest, but seems to be holding up, give it a shot if its not to late!

  74. Jeanine September 10, 2013

    I installed a penny floor in a small area and have read that you can use the spar varnish to cover the pennies and make them water proof. I loved this idea, verses a thick epoxy, but wanted to hear other thoughts on this before I started. Thanks for your help! :)

  75. Nicole September 28, 2013

    We just purchased a home that has age and distressed pine flooring that is 3 and 1/8″ wide. In the majority of places, there are spaces of up to 1/8″ between the boards. After sanding and staining, the previous owner used Minwax Water Based Poly on the floor and, with seasonal temperature variations and regular use, the poly cracked and crumbled out of the gaps over time. At this point the gaps are basically cleaned out of finish from the cracking out over time. I assume that this cracking is because the poly was too hard of a finish for this particular pine floor in this particular location? We have cool winters and very humid summers. Is using a high quality spar varnish on this floor the worst idea ever? Would it be possible to fill in the gaps with spar varnish? I ask because the house is in the middle of the woods in a remote location and the gaps are collecting insects and serving as a place for insects to rear offspring. The gaps are not very deep, as it is tongue and groove flooring. I have considered the “splintering” method of filling the gaps, but wondered what you thought of using a quality spar varnish? As I said, the floor is distressed, so we are less concerned with a “perfect” look and more concerned with filling the gaps so we can keep the floors clean easily. If you think the spar would serve our purposes, do you think we can just scuff sand the semi-gloss water based poly, clean, and then apply the spar?

    •  

      Hey Nicole. My first and best advice is to consult with a flooring professional. I finish furniture, and flooring is a different beast. I have absolutely no professional knowledge and can only apply what I know of furniture, which may steer you in the wrong direction. That said, you should be able to scuff sand, clean, and then apply a spar varnish. Spar varnish will be quite flexible and should do ok on a surface that has some movement. I wouldn’t count on any film finish to fill the cracks though. That’s going to be a bit tricky to do. The movement between the boards is necessary so filling them either ends up with the filler pulling apart or resisting the necessary movement. Again, a pro could probably give you much better advice on this.

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