Ripping Plywood

[JimD]

My outfeed support is my casual workbench (casual because it is nothing fancy). It is made of 3/4 plywood and the top is a torsion box with a piece of 1/4 plywood (could me mdf) on top that can be easily replaced. 3/4 oak edging surrounds the outside of the top and helps to keep the sacrificial top layer in place. I made it 1/4 inch shorter than my table saw.

My router table is also 1/4 shorter than my table saw and can serve as my infeed support. Even with stable infeed and outfeed support, I do not rip full sheets on my table saw. Part of the reason is that it is too hard to get everything in the right position in my somewhat small shop. Part of the reason is that it is still hard to keep the sheet against the fence even with good support. Full sheets are just hard to handle.

A roughing cut with a circular saw followed by a finish cut on the table saw is what I would recommend and where you seem to have ended up. I have a lattice of 1x4s on edge I use to support the plywood during the rips. I often just put it on the table saw but sometimes throw it on some sawhorses out in the driveway.

Jim

[DaveS]

I made myself an 8' saw board and with a good blade in my circular saw, I can rip plywood with it and end up with a cut (almost) as good as with my table saw.

Good side down, masking tape on the top to prevent chip out, and I usually score the veneer with a sharp utility knife when I cross cut. Also, be sure to adjust the blade so it just barely comes through the plywood surface.

The way the saw board works, it is very fast to set up the cuts.

[pelligrini]

Also, be sure to adjust the blade so it just barely comes through the plywood surface.

I've always been under the impression that having the blade extended as far as possible would give a cleaner cut. It is not as safe though. When the blade is set so just the teeth barely come through more teeth will be in the wood at all times during the cut. I thought chances of burning, teeth marks and tearout are greater with having more contact with the teeth.

[cabinetman]

I've always been under the impression that having the blade extended as far as possible would give a cleaner cut. It is not as safe though. When the blade is set so just the teeth barely come through more teeth will be in the wood at all times during the cut. I thought chances of burning, teeth marks and tearout are greater with having more contact with the teeth.

I agree. The higher the blade, the lesser the angle. It will also produce less lift on the stock.

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[DaveS]

I agree. The higher the blade, the lesser the angle. It will also produce less lift on the stock.
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I have found for me that if I have the blade out farther, I get more splintering.

If I keep it shallow, I tend to get a cleaner cut on the side facing up.

Might be the blades I use?

Maybe I am just talking out my back side though....

[radhak]

I have found for me that if I have the blade out farther, I get more splintering.

If I keep it shallow, I tend to get a cleaner cut on the side facing up.

Might be the blades I use?

Maybe I am just talking out my back side though....

Matches my experience :

High blade : more splintering along the cut on plywood, but less burn or teeth marks

low blade : less splintering, but more burn and teeth marks.

[Cochese]

Try using painter's tape as well.

[pelligrini]

Maybe the high angle does contribute to the splintering on plywoods. I was really basing the premise on what I see with hardwoods on my tablesaw, as well as other discussions I've read about it.

[jdon]

I dimly recall being told to set the blade height so the gullets between teeth just clear the wood surface, to keep sawdust from clogging. Anybody know whether this is based on fact?

[Bruce Cohen]

Rob,

As promised, here's the diagrams for ripping and crosscutting sheet-goods using 2X4's.

You need 6 2X4's, with 2 cut in half, the other left full sized. You'll also need a straight edge that slightly longer than 8' along with 2 clamps. Lee Valley has one, which I use. Although I got it when I had a lot of money to waste and not enough experience to know better. It's part #05J50.01 and sells for $145.00. Yup, it's pricey, but I do love it.

Looking at the diagrams, you clamp down the straight edge and add the amount of overhang from the blade to the end of the heel plate of your circular saw. For repetitive cuts, you can fashion a jig to locate the straithe edge without taking measurements more than once.

It's important to use a "good" blade (I've found that Freud blades work great, also masking tape over the cut line to prevent chipping of the outer plys. I tape both sides, and always cut with the good side facing up.

All this sounds way harder and longer than it really is. See the diagrams, it almost idiot proof.

If you still have any questions, PM me.

Best,

Bruce