Newbie needing TS plywood cutting advice

[Christopher Wright]

I'm brand new to woodworking. This is a fantastic forum!

I'm a about to order a General 50-185 table saw w/50" fence and a
HTC mobile base.

I have a few questions about saw blades, plywood and kefs.
I'll mostly be cutting (ripping and crosscutting) large sheets of quality 3/4" plywood.

Is the Forrest Duraline HI- A/T the kind of blade I should be looking at, or is this blade mainly for cutting "thin" plywood?

I've also heard about special plywood blades from Systimatic.

What about the kerf? What's the advantage/disadantage of a 3/32" vs. 1/8" kerf?

Any advice would be greatly appreciated.

Thanks,
Chris

[Carole Valentine]

Welcome to woodworking!

The Forrest Blade you mentioned would certainly work wonderfully, but plywood is hard on blades. Personally I would go with a less expensive ply blade, but that's just me. I do use a Forrest WWII for hardwoods.
I think the thin kerf is mostly for the lower powered saws and I think your General is 1.5 hp so it should be fine. Just remeber that a lot of splitters can;t be used with thin kerf blades and if you don't do anything else...use a splitter. Large sheets of 3/4" ply are hard to handle on a cabinet saw, not to mention a contractors saw. I would recommend cutting to rough size with a circular saw, jig saw or even a hand saw before moving them to the table saw for final dimensioning.

Another newbie who knows nothing put puts her two cents worth in anyway!

[Jim Becker]

Carole's excellent advise applies very well to your situation. Ditto in every way.

[Chris Padilla]

Chris,

Check into "The General" by CMT (www.sommerfeldtools.com and www.woodpeck.com are two sources off the top of my head but Google around) is a good all-pupose blade for cross/ripping sheet goods. If you don't mind switching blades for ripping/crossing, CMTs Fine Cut-off is excellent for crosscutting plywood and then leave the General for ripping. These blades are cheaper than Forrest but I like them quite a bit. All my router bits and saw blades are CMT.

Thin vs. Reg Kerf: Stick with 1/8" kerf...it is an easy number work with and you'll want the extra mass behind the carbide. I've had issues with deflecting blades with thin-kerf but only when cutting hardwood...haven't tried a thin-kerf on plywood...no reason to use it there.

Ripping a full 8' sheet on a cabinet saw by yourself is definately do-able (I do it all the time) but you must have the outfeed all ready and a good sharp blade, smooth table surface, and above all, a good solid fence to push against to avoid burning. It is an artform to get a good clean 8' rip on sheet good by yourself. Practice makes perfect. Just plan to rerip that first edge 'cause it will probably have burn marks and gouges from the ply shifting as you dance along the TS. Cut it a little long!

[Christopher Wright]

Thanks everyone for the info. I looked into the CMT Fine Cut-off blade.
Looks like a good direction to go in. Will that one be pretty chip free?

I do have a fairly new Craftsman carbide combo blade on my radial arm saw that I could try in place of the "General" blade from CMT.

Also, good ideas about cutting the sheet down to a more managable size with a jig saw or circular saw first. I have both.

This is a really great forum with lots of helpful people.

Thanks again,
Chris

[Steve Clardy]

Thin kerf v/s 1/8".
Either blade will work for plywood, preferably one with 40 teeth.
Thin kerfs were made to save wood. Less kerf, more wood left. But they do work better on under powered saws also.
I use thin kerfs on a 3hp table saw, which actually gives you more power.
There isn't any reason to pre rip ply with anything else to break it down. It can all be done on the table saw. Just build an outfeed table, and a side table to the left of saw, that will support the extra width of the ply hanging off the table saw.

Steve

[John Miliunas]

Welcome to the Creek, Chris! Great place to hang out. You've gotten some super info, thus far, but your last post is begging for this bit of information: If you're going to be doing crosscutting on the TS, *especially* ply, you'll want to set yourself up with some type of zero clearance (ZC) insert in place of the stock one. This will help support the material on the underside of the cut, reducing the splintering. In case there isn't a ZC insert available for your saw or you don't have the info or time to make your own, another option is to mark the cut line on the table side of the sheet and run a strip of masking tape down the entire cut line. This too will help reduce the tearout. Enjoy your new saw and, if you plan on hangin' around here, once you get it, that counts as a "gloat" and gloats are to be accompanied by PICTURES! Got it?! Good! Now go make some sawdust!

[Charlie Plesums]

If you are using really good plywood, as hinted at the beginning, you will probably be cranky about any tear out. And the veneer on the $120 per sheet stuff is probably too thin to measure.

When I am in that mode, I cut my pieces at least 1/2 inch too long, but as small (easy to handle) as possible. For the final dimension I first cut about 1/16" deep, so the teeth are going through the surface horizontally rather than pulling down. Generally this gives a very clean bottom cut. Then I make a second cut through exactly the same kerf, with the blade extra high, so it is cutting into the top layer somewhat vertically. Of course, a sharp plywood blade and zero clearance insert are minimum, and sometimes I also used the tape trick.

Remember that the tear out problem is primarily on cross cuts, not on the rip direction.

If you consider this too much bother, as I do, then you start looking at monster saws with a separate scoring blade.

[Michael Ballent]

Another way to minimize tear out from the cut is to use a zero clearance insert in place of the standard insert that comes with the saw. You can make one out of MDF plywood or you can just buy one. The only thing is that guard and splitter that come with the saw will probably no longer work so then you are looking at an overarm guard and some other splitter.

I am sure that you have seen many woodworkers on TV that do not use the splitters and/or guards and IMO they are just tempting fate. The thin kerf blades sometimes are not compatible with the splitter. Without a splitter you are looking at potential kickback.

Just want to be sure you are safe while woodworking, it's hard to do woodworking with bandages.

BE SAFE!!!

[Christopher Wright]

Wow! Thanks for all the great advice. I've learned a lot just from this post alone.

I'll be sure to post some pics as soon as I get the saw in.

Thanks again!
Chris

[Ed Hardin]

another way to minimize tearout is to put tape down over where the cut will be made and cut through the tape. Works for me.