Stop Tearout in Plywood

This article was inspired by a question from Steve. He writes:

I have recently embarked on building bookcases and I have run into an issue. I decided to use a cabinet grade birch plywood that I picked up from the hardwood dealer here in Dallas. Everything was fine until I started the cross-cuts and experienced tearout on the top layer of the plywood face. I stopped this by doing all my cuts with a skill saw and plywood blade. But when cutting the dados, I still got quite a bit of tearout. I like using this plywood because its inexpensive. So my question is: how do I stop tear out on plywood?

There are few key things that you can do to prevent tearout in plywood. First, use a zero clearance insert on your tablesaw. A zero clearance insert fully supports the wood fibers right at the cut line, which will dramatically improve your cut quality. You can buy insert blanks specifically made for your saw, or you can just make your own from plywood or MDF.

The second thing you can do is use a high quality, high tooth count blade. I generally use a 40 tooth Forrest Woodworker II or a Tenryu 40-tooth Gold Medal blade, and that works just fine. But if you are still getting tearout, you might try a blade with 60-80 teeth, such as this one from Freud. More teeth equates to a smoother cut and less tearout. You’ll also notice a key element of that particular blade is the Hi ATB (alternating bevel). This means that the teeth on the blade are milled at a high angle for more effective scoring of the plywood, thereby creating less tearout.

Now for the dado blade, it just comes down to sharpness and the properties of your particular dado stack. Some of the more budget-friendly dado sets will give you tearout no matter what you do. But the higher quality dado sets will produce tear out free cuts until they start to become dull, at which point you’ll send them out for sharpening. I use the Forrest Dado King, which I picked up used about 6 years ago. But before that, I used this Freud dado set with great results. In fact, I still think this Freud set is the best balance of price and performance.

Another thing you can do to prevent tearout involves our old friend blue tape. Just run a strip of blue masking tape along the cut line on the side that you anticipate tear out. The tape helps to hold the fibers in place during the cut, and usually the result is a clean crisp line. But with a zero clearance insert and a high quality blade, this step is usually unnecessary.

And the final thing you might try is making a scoring cut (image borrowed from American Woodworker). If you raise the blade about 1/32″ and make a very light initial pass, that will usually cleanly sever the fibers on the face of the plywood. That way, you can make a second pass with the blade extended and you’ll end up with a tearout free cut. A number of larger saws out there are actually outfitted with a second blade that lives in front of the main blade, and its sole purpose is to make this type of scoring cut.

Category: Techniques

Comments

  1. mark williams January 25, 2010

    Marc,

    You read my mind! I just posted in the community today, Which DADO? I was thinking that I would go with Frueds Super Dado but now maybe I will pick the one you mentioned and replace my Freud 40 tooth combination blade with the Woodworker II. Do you think that would be more bang for my buck??

    •  
      thewoodwhisperer January 26, 2010

      Yes I do! ;)

  2. Dennis January 25, 2010

    I have had great results with the Dado King from Forrest. I also use a home made zero clearance insert.

  3. Eric January 25, 2010

    I’ve found that masking tape doesn’t work very well for me.

    The best solution I’ve found which keeps me from having to change my blade to a crosscut blade, is to make a score line with a very sharp utility knife and a straight edge. I make a light cut at first and then follow the line a few more times until the outer veneer is cut thru. Carefully though. The knife blade can veer off course if you try to take to heavy of an initial cut. Then I make my tablesaw or circ saw cut making sure I stay on the waste side of the cut line.

  4. The zero-clearance insert (ZCI) makes a huge difference. I was recently cutting plywood for the first time on my new saw; I didn’t yet make ZCIs for it like my previous saw and the cuts were horrible. Stopped everything to make the insert and everything came out great.

    You mentioned that the tear out is on the top. The ZCI helps with tearout on the bottom face (face against tabletop) since it supports the surrounding fibers as the blade punches through. For tearout on the top, the solution is to raise the blade higher. If you have the blade, say, 1/8″ higher than the plywood surface, the tooth is whacking the uncut wood nearly head-on; some fibers may splinter up. Imagine raising the blade to 1″ above the plywood. Now the tooth is swinging down nearly perpendicular to the surface of the plywood so it cuts the fibers with them supported by the rest of the plywood.

    The dados by nature will have a shallow angle to the wood since they are buried in the wood, but they normally have batwings that score the wood before it hits the rakers.

    P.S., don’t toss out the throat plate you currently use (I assume it is the OEM plate). You’ll need it for bevel cuts. I hang my OEM plate from the handwheel for setting the bevel angle so I don’t forget to switch it out; the handwheel has great mechanical advantage over the blade trapped in the ZCI. Don’t ask how I know.

    • Dan Drabek January 26, 2010

      “I hang my OEM plate from the handwheel for setting the bevel angle so I don

  5. Chad January 25, 2010

    I used to have the exact same problem. Marc described what I did to solve the problem almost exactly (I’ve never needed to resort to scoring cuts). Now I have nice clean cuts. Good advice Marc.

  6. Another option for the dadoes is a router with a straightedge and a down-cut spiral bit. It’s worked pretty well for me for both plywood and solid stock.

  7. Dave Odekirk January 25, 2010

    Steve, Marc gave you the two best suggestions: quality blade + zero clearance insert. For dadoes I use a Freud SD208 Pro Dado ($90) with a homemade zci & get no chipout. You’ll need to make different inserts for different dado widths. For normal cuts I use a Freud Avanti combination blade ($40) with a homemade zci & get absolutely no chipout. I have a Forrest WWII in the box yet and don’t plan to use it until I have to toss the Freud. So big bucks are not necessary. Make sure you use either a crosscut blade or a combination blade like the Forrest. Rip & multipurpose blades just don’t crosscut well. And keep your blades sharp. I haven’t had any luck with the blue tape method, though.

  8. Sometimes all three and a Sharp knife. They Ply we get around here has such a thin veneer it will chip no matter what you do. looking at it cross eyed will cause it to splinter So I cut wide ( like marc showed me) use tape. (like marc showed me) use a sharp 60 to 80 tooth blade. ( like marc showed me) and score the heck out of it with a utility knife. This works most of the time.

  9. Tom Collins January 26, 2010

    Using the Woodworker II, I have never had any tear out. A sharp high quality blade is definitely worth the investment. And realizing when it is time to get it sharpened is equally important.

  10. Heath January 26, 2010

    On the subject of dados… I don’t have a stacked dado set yet, but I have two wobble dado blades. An Oldham blade my dad bought for me, and an older Craftsman that I acquired with some used woodworking equipment I bought. The Oldham blade is terrible. The bottom of the dado is not curved as with some wobble dados, it is a series of stepped ridges getting progressively deeper toward the center. The Craftsman blade, however, works great. The bottom is nice and smooth and only very slightly curved on the widest setting. Not a problem with stopped dados or where the edge will be concealed. The main problem with it is it’s a real pain to adjust.

    Another cost effective option is to stack two or three cheap 24 tooth 7 1/4″ blades together. Just make sure to alternate the teeth so they don’t touch. I know the safety and effectiveness of this is much debated, but it seems to work quite well for some people.

  11. Matthew Hills January 26, 2010

    The advice here is good. A ZCI is very helpful. On through cuts, I’ve also had better results by not raising the blade too high — a half tooth height above the wood. Dadoes — I’d recommend doing a skim cut first. My dado set (the old delta stacked dado set) has pretty good cut quality. I’d expect similar from Freud.

    Matt

  12. I bought an 8′ x 4′ piece of styrofoam insulation. Lay your plywood on top of that, with the blade on your circular saw just a little deeper than the thickness of the wood. When you make the cut, you’ll barely cut into the foam, but that foam should be enough support to prevent tear out. I’ve had good success with this method of ripping/crosscutting my sheet goods.

    • That will only help the bottom side of the workpiece. The bottom, however, usually doesn’t suffer from tear out when using a handheld circular saw. The top does. Before I had the Festool TS-75 I used a Porter Cable Mag something or other. I made a straight edge cutting guide/Zero Clearance from hardboard and maple.

      See this link…

      http://www.woodsmithshop.com/d.....odtips.pdf

      It worked GREAT for me for years!!! With my router AND my circa saw. I also used 2″ pink rigid foam insulation for the bottom. Mainly to keep the blade away from my concrete floor.

  13. I just picked up the Freud dado set you recommended, Marc, and I’m very happy with it. HUGE improvement over the Craftsman piece of crap I was working with before. The new Freud plus a zero clearance insert gave me great results on the box joints I just cut for a project I’m working on.

  14. Cody C January 26, 2010

    Here’s how one woodworker works around this problem.

    http://woodgears.ca/shop-tricks/tearout.html

  15. Dan January 27, 2010

    Good information about eliminating or reducing tearout. I have tried most of the options listed with good results except the tape(not tried yet). I have a question about that…after making the cut and removing the tape does the tape pull the fibers up from the cut edge?

    •  
      thewoodwhisperer January 27, 2010

      Usually no. But as a precautionary measure, its good to pull the tape off at an angle toward the cut.

  16. Well, once again, the best thing for tear-out and other woodworking stuff is to read The Wood Whisperer! Great advice Marc!

  17. Steven April 8, 2010

    Hi Marc,

    I’m a little confused as to what the zero clearance insert actually does. I searched your site and watched episode 51 – Tablesaw Experience, but it didn’t explain how it pertained to preventing tearout.

    Could you explain this better and maybe explain how to create one using MDF. Sounds like a perfect Whisper Mini.

    Thanks,

    Steven
    Denton, TX

    •  
      thewoodwhisperer April 8, 2010

      Hey Steven. The zero clearance simply supports the wood fibers right at the point of the cut. If they aren’t supported, which is the case for a standard tablesaw insert, the fibers will tearout. So for best results, you want to make an insert for a particular blade, and generally never use it with any other blade. Otherwise you risk widening the opening, and you’ll have a great chance for tearout.

      As for making an insert, that’s going vary a bit from one saw model to another. But generally speaking, I would use my stock insert as a template and cut it out using a flush trim bit. You are right though, a great idea for a mini. I will keep that in mind.

  18. Steven April 8, 2010

    Thanks for the reply Marc. Quick response time. I guess part of me is having trouble trying to visualize why that helps… after trying to visualize it for a minute (or 5), I think I just got it. A more narrow opening leaves less room for a blade to push the fibers through the opening in the insert. (Another 5 minutes later during editing mode)One more thought… That sounds like a Z-Word for the glossary on newtowoodworking :) I noticed there were no Zzzzzzz’s

    Sorry I’m a little slow tonight… Long drive back from Austin.

    Thanks again,

    Steven
    Denton, TX

    •  
      thewoodwhisperer April 8, 2010

      No problem man. One of the best ways to visualize it is to actually do it and compare with and without. It becomes pretty clear once you see it. And its a little tricky to explain….

  19. Gary Griffith June 22, 2010

    I have used a scrap piece of ply under the work piece, it acts as a ZCI. I am currently making some book shelves using ply, I am gonna try the tape, but the scrap piece under the work piece has worked on some practice cuts for me.

  20. Doug M. January 9, 2011

    Took a couple cabinetmaking classes and was able to use a commercial saw with the secondary scoring blade, downside- scoring blade needs to be finely tuned it trimmed through my plywood veneer about 1/64″ away from the actual cut. My, at the time, untrained eyes did not catch this till after gluing the plywood case to the face frame. Resulted in a dark line at the surface of the joint that remains today. As a finish carpenter I have many times had great success cutting down cheap hollow core veneered slab doors using the blue tape and score the line with a utility knife technique, but cuts made with a portable circular saw and guide instead of a table saw. a sharp Freud diablo finish blade was used. This can also be somewhat remedied with plunge cut track saws Like Festool and others offer now, kind of expensive but nice to use.

  21. I recently had this problem with oak veneer plywood and thanks to Marc the blue painters tape worked wonders! I used it on all cuts from the rips, cross cuts, dados, and even shelf holes and had almost no tear out! Thanks for the tip!!

  22. Andrew Howland January 17, 2012

    Marc, do you have any suggestions for repairing tear out with veneer plywood?

    •  

      Unfortunately, because of the super thin veneer, it can be a real pain in the butt to fix. Its like a thousand little splinters of wood. There really is not effective repair. So prevention truly is the key. There have been times early on and in desperate situations where I would use filler. But these days I just grab a new piece and cut it properly. :)

  23. drdarynm August 10, 2012

    The homemade 2 piece guide for the circular saw works just like a zci. Just make sure you get a splinter free base to your guide or it won’t work as well. Using mdf is also a good way to prevent tearout with any cut, but that dust is murder on the nostrils and sinuses without a mask, even in the outdoors. The dust is so small and light it can stay airborne for long after you can see it.

  24. Nate Clark December 18, 2012

    I’ve got a 1987 Shopsmith sawsmith 2000 and I’m trying to figure out how I can make a zero clearance insert…the throat plate is 31″ and only 1/8″ thick….maybe plexi. but for now the blue tape with a combo blade gets me by.

    • Brandon December 26, 2012

      I’d be curious to know how the 1/8″ plexi works out. I have a craftsman that will require an 1/8″ plate as well. I’be been looking for something thin yet sturdy enough. Plexi might be the ticket.

  25. Boliver Tagnasty March 27, 2013

    Sometimes, you just have to make cuts on full sheets of veneer lumber core with ye olde circular saw. And the point about the ZCI is still valid, you just have to make one for your circular saw as in the following video clip.

    http://www.finehomebuilding.co.....arout.aspx

  26. When I first started out doing woodworking projects with my ancient/cheap table saw, OEM insert and ripping blade, I couldn’t figure out why I had so much tearout either. :) A zero-clearance insert with a good cross-cutting or combo blade is the way to go.

  27. Raul July 1, 2014

    I’ve found that a high quality, high tooth count blade in the neighborhood of 60-80 will give you a smoother and even cut. Go lower than that you might be asking for trouble.

Leave a reply

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Online project based woodworking education.

3 Membership types

  • A la Carte
    Starting at $25/project
  • Subscription
    $129/year
  • Superfan Subscription
    $299/year
Learn more →

Simple Varnish Finish DVD

Coming Up


  • Video: Bottom Shelf & Assembly

    November 7, 2014
  • TWW Live

    November 10, 2014 - 11:00 am MT
  • TWW Live

    November 10, 2014 - 11:00 am MT
  • Video: Risers & Drawer Pull

    November 14, 2014
  • Video: Finish

    November 21, 2014
TWWGiveawayCT36
bellforest200x200-tww10
EagleAmerica
Image Map
woodwhisperer-200x200-August-contour-300614
CPT 200x200 Ad v4pre
Advertisement