Old Freud saw blade problem

[Ron Coleman]

I've got an old (25 years) Freud LU73M, 60 tooth blade that has acted really strange from day one. Mounted on a table saw the blade will start to "ring" shortly after you start the saw. The longer the saw runs the ring gets louder and louder and louder till you shut the saw off. I've used this blade on two different table saws with the same results. I tried it on an old radial arm saw and there was NO ring whatsoever. I even had a saw company examine it one time to see if it had any cracks, no problem they said.

Today I tried the blade again and got the same old ringing problem, so I put some small pieces of Scotch tape over the expansion slots and holes and NO ring. For some reason the close proximity of the table insert and other saw parts must start the blade oscillating.

The sound isn't the typical saw blade whine, it like a ringing bell that get louder. If you start cutting shortly after starting the saw it doesn't ring till you're finished with the cut.

Anyone ever have a problem with a ringing saw blade?

[Dave Falkenstein]

Convert it to a shop clock? :)

[Ben Grunow]

I had a delta contractors ts (1990 vintage) that did that with, as far as I can remember, any blade. Never tried the tape but wish I had because that ring is earsplitting. Strange stuff. It was harmonic in that it got worse if you didnt cut.

[glenn bradley]

Putting tape over the expansion slots is an old trick for noise reduction on a TS blade. I read about it in FWW IIRC. The plate should be enough thinner than the teeth to allow a reasonable amount of life out of your tape application. When it eventually wears off, stick on some more. Many folks do this even if the blade doesn't ring. Try it on your other blades and I think you'll find a noise level decrease there as well.

[Howard Acheson]

Fill the expansion slots with silicone adhesive sealent. It will stop the noise and will not affect the operation of the blade.

[Ron Coleman]

Fill the expansion slots with silicone adhesive sealent. It will stop the noise and will not affect the operation of the blade.

That was next on my list of things to try.

Thanks

Ron

[Charles McCracken]

Ron,

There are two likely causes for the whine:
1. The blade is out of tension
2. The air being pushed by the gullets/expansion slots is causing a harmonic reaction with the throat plate of the saw.

If it is the first the blade can likely be re-tensioned by a well equipped blade service. For the second you should look at the height you are running the blade and the throat plate you are using. A zero clearance plate may alleviate it and keeping the blade low in the saw may also help. The problem with filling the expansion slot with silicone is that it would be difficult to make it stay in place. You would not want pieces to be flung at the operator at 100mph.

[scott spencer]

Hi Ron - Freud still makes an LU73M010 (http://www.amazon.com/exec/obidos/tg/detail/-/B00004T79F/ref=ord_cart_shr?%5Fencoding=UTF8&m=ATVPDKIKX0DER&v=glance). Assuming you've got the 10", Amazon has it on sale for 25% off...~ $34 shipped. After 25 years, you might consider replacing it, and having the old one sharpened and fixed if it still has sufficient carbide.

[Ron Coleman]

Ron,

There are two likely causes for the whine:
1. The blade is out of tension
2. The air being pushed by the gullets/expansion slots is causing a harmonic reaction with the throat plate of the saw.

If it is the first the blade can likely be re-tensioned by a well equipped blade service. For the second you should look at the height you are running the blade and the throat plate you are using. A zero clearance plate may alleviate it and keeping the blade low in the saw may also help. The problem with filling the expansion slot with silicone is that it would be difficult to make it stay in place. You would not want pieces to be flung at the operator at 100mph.

Charles

Thanks for the reply.. I tried a zero clearance insert and it didn't do much so I tried it without any insert, same problem. I think for the time being I will stick with the tape and the next time I have some blades sharpened I'll have them do the tensioning.

I fed the blade a few feet of beech this morning with the tape in place and it stuck right in place with no marks so it should last for a while.

Ron

[Travis Gauger]

I had a forrest WWII that did the same thing. I stood back and let it go once for a minute or so and it got loud enough to hurt my ears. Scared the heck out of me so I returned it. Got another one and no problems. If you got 25 years of service out of this blade, why wouldn't you just replace? When I was in school there was a bandsaw with a carbide tip off the tablesaw blade imbeded into the front top wheel cover. If that thing would have hit someone, they would have been hurting for sure. Any time I put a new blade in I think af that bandsaw.

[Ron Coleman]

Travis

This blade has really low mileage since I haven't ever used it much. I recently found it when I was looking for some other stuff and then remembered why it was in the back of the drawer.

Most of the time I keep a 40 tooth combination blade on the saw.

I'm getting ready to do some segmented turnings and it will be a good test to see how the old blade performs on hundreds of miter cuts.

[Lee Koepke]

Travis

This blade has really low mileage since I haven't ever used it much. I recently found it when I was looking for some other stuff and then remembered why it was in the back of the drawer.

Most of the time I keep a 40 tooth combination blade on the saw.

I'm getting ready to do some segmented turnings and it will be a good test to see how the old blade performs on hundreds of miter cuts.
maybe the blade is telling you to use it more often ... it could be lonely !!!

:D

[Charles McCracken]

Travis

This blade has really low mileage since I haven't ever used it much. I recently found it when I was looking for some other stuff and then remembered why it was in the back of the drawer.

Most of the time I keep a 40 tooth combination blade on the saw.

I'm getting ready to do some segmented turnings and it will be a good test to see how the old blade performs on hundreds of miter cuts.

By "low mileage" do you mean it has not be sharpened? All of our blades and cutters have a Lifetime Warranty that you may be eligible for. Check out the details here:
http://www.freudtools.com/t-warranty.aspx
If it's within the guidelines send it to my attention at the address listed on the warranty page.