tearout on plywood

[johnny means]

I'm in the scoring pass camp. I don't even do a 16th, just enough to shave off the veneer. The key is to plan for easy reliability between setups. I'll usually clock my handwheel so I can raise and lower to the same heights easily.

[Ray Gutnick]

I've had pretty good luck with painters tape, but the other suggestions are solid

[Warren Lake]

They make negative hook dadoes for plywood. The blade on the bottom is from one of my regular sets, the blade on top is from a plywood set. The outside chipper on the bottom blade leans well forward, on the top blade the teeth lean backwards. Your material needs to be decent quality. I havent bought dadoe sets for years but all of them were likely 225.00 - 250.00 Can a set and im going way back.



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[Bob Jones 5443]

Johnny Means sums it up for me. Set up the fence for the cut. Raise the blade just enough to kiss the sheet. Run it through, making the very slightest of scoring lines. You should then be able to raise the blade for the full dado depth and get no tearout.

[Curt Harms]

Johnny Means sums it up for me. Set up the fence for the cut. Raise the blade just enough to kiss the sheet. Run it through, making the very slightest of scoring lines. You should then be able to raise the blade for the full dado depth and get no tearout.

I do that when cutting melamine. I use a triple chip grind blade and make a very shallow pass first then cut off. My dado has the little 'bat ears' I think they're called. I think my next dados are going to be cut with a router. I made a jig that when used in conjunction with a top bearing 1/2" X 1/2" straight bit cuts very clean dados. The jig enables me to set the dado width to the plywood as long as the dado is at least 1/2". There's a jig that uses a bushing but works similarly. I haven't messed with that one yet.

[Gordon Stump]

https://www.amazon.com/Freud-Super-Dado-Sets-SD508/dp/B00004RK0P

All of the suggestions are right on. But a dado set designed for veneered plywood is a good start. I found that expensive old stock birch plywood from my lumber yard had more chip out than cheaper poplar core plywood. The fir core or the gluing process seemed to chip out even with a dado blade designed for melamine or veneer plywood.

[Kevin Jenness]

For shelving, why use a dado anyway? Butt joints with biscuits , splines or dominos are sufficiently strong.

[Jim Becker]

For shelving, why use a dado anyway? Butt joints with biscuits , splines or dominos are sufficiently strong.

Dados likely are stronger and help to deal with racking, but even if that isn't the case (pardon the expression... ) there is the appearance factor. Some folks like the look of the exposed joinery; some do not. That's subjective.