Best blade for plywood...

[Dave Gaul]

I was getting ready to cut some 1/4" Birch ply for a drawer bottom, and when it came time for blade selection, I assumed that my Freud 80T Laminate/Melamine blade would be best, but then I noticed that my Freud 80T Crosscut blade said it was "best for" plywood, and the Laminate/Melamine blade on list plywood as "ok/good for"...

The crosscut blade has a hi ATB grind, while the Lam/Mel blade has a TCG grind.... so why would the crosscut blade be better than the Lam/Mel blade for plywood?

[Rod Sheridan]

Hi Dave, the TCG blade is designed for abrasive, dirty materials such as particle board and MDF.

The tooth style is a flat tooth similar to a rip blade, with trapezoidal teeth as well (The triple chip tooth).

This tooth configuration resists becoming dull in abrasive materials, however it doesn't provide a shearing action required to cleanly sever wood fibres such as in ply or solid wood.

A good crosscut blade (Alternate tooth bevel) will shear the fibres in the plywood cleanly, however this tooth style becomes dull much more rapidly when cutting abrasive materials.

I use a standard 60 tooth ATB for plywood, it cuts very cleanly.

try your two blades out and you'll imediately feel the difference in feed rate, smoothness of cut etc.

regards, Rod.

[Prashun Patel]

Your drawer bottoms will likely be recessed into the sides, so I'm not sure you need to be all that concerned about it.

That being said, when I need to cross cut plywood cleanly, I mask the cut line with tape, use a ZCI, and if I REALLY want to be sure, I'll score the line with a straight edge and utility knife.

These tricks work well enough for me that I do my plywood xcutting with a 50t combo blade.

I've never had luck with those melamine blades. They end up dulling after a few cuts - way before I expect them to, and then I end up burning a cut or two b4.

Even better than a ZCI, you can make a 1/4" cross cutting sled that'll help keep the fibers from lifting.

[Dave Gaul]

Rod, thank you very much for the detailed explanation! Exactly what I was looking for.

Prashun, the bottom was rabbeted into the sides, but I do still want to use the right blade for any task, maximizing the life of each blade. I do also have a combo blade, and a gen blade as well that I could use when the cut quality is hidden... Thanks for the razor blade tip, I will have to try that! I did still get a little chip-out with the crosscut blade, even with a zci... chip-out occured on the top of the ply, not the bottom... If I get into cutting alot of ply, I may make a sled as you suggest..

[scott spencer]

Dave - A sharp Hi-ATB blade with a high tooth count and the precision of a Freud should leave very little tearout, but it depends on the ply itself, sharpness of the blade, the saw, feedrate, etc. Blades like the Forrest Duraline, Infinity Ultrasmooth 010-080 & 010-060, CMT 210.080.10, Freud LU79/LU80, and Amana MB10-800 are about as good as they get for clean cut.

As Rod pointed out there's no free lunch with any design. The steep bevel angle of a Hi-ATB is more prone to abrasion than a triple chip or even a flat tooth, but neither of those grinds sheers as cleanly as the Hi-ATB or ATB grinds. With some of the tricks mentioned you can get good results from several grind types though.

[Dave Gaul]

Scott, I figured I get some great words from ya!!

The blade is a fairly new (< 6 months) Freud TK806. The saw is a fairly well tuned R4511. The ply was 1/4" birch from Lowe's, so I'm guess the minor tearout was due to the quality of the borg ply... unless maybe my feedrate was too fast.

Great discussion, I've learned alot already! Thanks!

[Rod Sheridan]

Dave, even when I had a 1 1/4HP contractor saw, I used standard kerf blades.

I find they cut better than the thin kerf blades, and even 1 HP is plenty with a sharp dedicated purpose blade.

Regards, Rod.

[Lee Bidwell]

Hi Dave,
I can't add much to the info you got from Rod and Scott, but I did find the illustrations here (http://www.dekalbsaw.com/glossary.html)helpful for understanding the differences between TCG and ATB.

Lee

[Dave Gaul]

Dave, even when I had a 1 1/4HP contractor saw, I used standard kerf blades.

I find they cut better than the thin kerf blades, and even 1 HP is plenty with a sharp dedicated purpose blade.

Regards, Rod.

I got hooked on TK blades from before I got my R4511 and only had a direct drive table top saw (delta). I bought TK blades thinking it would boost performance of the 1.75hp R4511. You are not the first I've heard saying that this is plenty of saw to spin full kerf blades. One of these days I want to get an Infinity Super General, and I'll be trying the full kerf version. I think I will end up going full kerf on all my blades once the TK's need replacing...

[Dave Gaul]

Hi Dave,
I can't add much to the info you got from Rod and Scott, but I did find the illustrations here (http://www.dekalbsaw.com/glossary.html)helpful for understanding the differences between TCG and ATB.

Lee

Thanks Lee, very helpful indeed!

[Dave Houseal]

I bought a Ridge Carbide Tool TS2000 blade and haven't looked back.

I get nice clean cuts in plywood and everything else. I just make sure I keep it clean and it cuts everything I through at it like butter.

[Gerry Grzadzinski]

I have the same two 80T Freud blades, and always use the crosscut blade for plywood.

[Craig D Peltier]

I have two there both HI ATB , one is Freud the other Forrest Duraline HI /AT Saw Blades (http://www.forrestblades.com/hiat.htm) . Freud was 80 and Forrest I think 130. Thye both dont leave any chipout unless its really thin veneer ( cheap ply) and if so only on the crosscut.
Anyhow I always turn to the forrest , it seems to push through easier ( even both been sharpened) and the blade feels more robust as well.

[Jay Allen]

I did still get a little chip-out with the crosscut blade, even with a zci... chip-out occured on the top of the ply, not the bottom...

If you are getting chip-out on the top of the panel (and the blade is sharp) then you have the blade set too low. The teeth are "pushing" the fibers foreward or even up, resulting in this chip out. Raise the blade some and the teeth will cut more downward. Don't go crazy with it, because this exposes more of the blade, which is a safety issue. It can also increase the tendency to tear-out the bottom.

[Howard Acheson]

Cross cutting hardwood veneered plywood will frequently result in "fuzzy" edge or chip out of the very thin hardwoood veneer. A high ATB blade is designed to slice the veneers cleanly minimizing this problem. The melemine blade is designed to cleanly cut composition wood material like particleboard and MDF. While the melimine coating is also quite brittle, the composition boards provide more support.

As others have indicated, there are other techniques that can be used to minimize or eliminate the "fuzzing" or chipout.

[Van Huskey]

I favor the Forrest Duraline for ply. Another technique is to make a scoring cut first then the through cut.

[Dennis Ryan]

I'm only an occasional browser and poster to these forums, so I hope you don't mind me jumping in here.

I find the easiest way to get great cuts in plywood regardless of the blade is to use a track saw. I recently cobbled together a quasi track saw like this one: http://www.youtube.com/watch?v=x8mTqlW3LPw and it makes great cuts with no tape, razorblades or chip-out. Since i had all the parts in my basement, it was basically free.