Scary!! Real Scary!!

[Dale Thompson]

Hi Folks,
As most of you know, I am over the legal driving age in Wisconsin. Only rarely do I get my ID checked at cigarette counters, bars or all of the strip joints up here in the northwoods.

Being the dunce that I am, I sent all of my "good" blades out for sharpening at the same time. However, since I was cutting some plywood and retained a decent plywood blade, I wasn't too concerned. For clarification, this involves a table saw (PM 66). The plywood cut with no problem.

Part of my project involved slicing some 2x4 stock in half so I grabbed an old Delta blade off the wall. It was a steel blade with a lot (~100) teeth with a slight rake so I don't think that it was a plywood blade. It may have been called a planer blade. Anyway, I sliced the first 12" long 2x4 with no problem. The second piece was one of those "tough" ones. That is not unusual. However, about 4" into the cut, I heard some rather unnerving sounds from the wood. That was followed by smoke and a STRONG tendency for a kickback. Fortunately, I was able to back the piece off. Remember, it was only 12" long. As I ducked and hit the off switch, I could see a severe "wobble" in the blade. I could also "hear" the wobble because the blade nicked the table insert, both front and back. The insert width is 3/8" so I would guess that the TIR on the blade reached close to 1/2"!!

My first thought was that the blade had come loose from the shaft or that a bearing on the saw had "melted". Neither was the case and when I removed the blade it was not bent in any manner.

Any thoughts?

Ben Franklin once said that, "GOD invented beer so that people could be happy." Now that I have listened to Ben, I can talk about this without shaking.

Whatever, please answer quickly. I am running out of glycerine pills and aspirin.

Dale T.

[Mike Cutler]

Your blade has overheated and lost it's temper is my guess. I had some skill saw blades do that. They looked flat as could be, but as soon as they hit wood they turned into spinning potato chips with teeth,serious smoke.

[Steve Clardy]

I has one particular brand of saw blades that would do that. Overheat when pinched, wobble really bad, eat up my zero insert plate. I would shut the saw down, and then restart. It had already cooled and stood right back up straight.

[Jerry Clark]

Dale, Probably just like when you use a hand saw and force the cut-- it binds and "wrinkles" up! And it is flat when you remove it. Be careful!

[Norman Hitt]

Dale, in addition to what's been said in the previous posts, I think that irrespective of the quality of the blade, that blade with "All the teeth" you mentioned, in combination with the Thicker wood, is the problem causing the excess heat. It's basically the same thing as using a bandsaw blade with too many TPI when resawing. You don't want too many teeth in the board at a time, and the teeth need to be spread apart with wide gullets to carry the sawdust out and cool the blade or it will overheat, and with heat comes stretch and warping. With the amount of wobble you described, I would be highly suspect of the integrity of it's metal at this point and would dispose of it, as it could possibly come apart while turning.

Be careful and Saw Safe.

[Karl Laustrup]

I gotta agree with what's been said so far.

I would get rid of that blade as it is very possible it has been weakened and you don't need 100 pieces of shrapnel flying all around the garage .

Not a good way to test your reflexes. Just my $1.398 worth of advice.

[Jeff Sudmeier]

Your blade has overheated and lost it's temper is my guess. I had some skill saw blades do that. They looked flat as could be, but as soon as they hit wood they turned into spinning potato chips with teeth,serious smoke.

I have has some circular saw blades do this as well. Normally it was the cheapest of the cheap blades that were very dull and over heated. Really when I was cuttin open roofs and cutting through a couple inches of shingles, plus sheeting and joists.

[Kelly C. Hanna]

Your blade got wayyyy too hot and went wavy on ya. I've had it happen in plywood with a skilsaw blade that was dull to begin with. Be very afraid of heat-wobbly blades!!

[Larry D. Wagner]

Dale,

I agree with what's been said! I have never found any steel blade that won't get hot and distort after even short usage, especially ripping with that many teeth.

Larry

[Bob Flemming]

Hi Dale

That certainly is to many teeth to be ripping a 2X4 with. Enough said on that.

I had a similar experience, with the blade nicking the insert. I was useing a 28 tooth carbide combination blade I bought on sale, from Sears. I was useing the insert that came with the saw, so I had plenty of clearence. I was cutting a piece of particle board, to this day I still do not know what happened to cause that heavy blade to flex that much. That one was unnerving to say the least.

[Dale Thompson]

OK Folks,
You can quit picking on me. I got my "good" blades back today and the "wobbler" will probably become a clock to remind me that I only have so many stupid moves left. Whatever, it will never see a saw again!

By the way, sharp blades cut REALLY nice! Get yours sharpened and see what I mean.

Dale T.