Bandsaw Blade Resharpening

[David Pascoe]

Before anyone replies that this topic has been covered numerous times and that I should search the topic, I've already done that. MY specific issue hasn't yet been mentioned and it is this:

I spent 3 years perfecting my method for sawing up to 8" wide veneers on my Delta 14. I routinely cut 24" x 8" x 1/16" tropical hardwood veneers perfectly, using Wood Slicer blades. They don't stay sharp long and the costs mount up using 2-3 blades/month, so I started resharpening using my Dremel and cylindrical chain saw stone.

The first resharp, and I kid thee not, makes cuts BETTER than a new blade. However, the problem arises with a second resharp causing the blade not to track straight. Moat often the veneer ends up wider at the top than bottom. I'm guessing that the 2nd resharp starts to alter the teeth offsets as I do not, nor can I, attempt to grind with the offsets.

For normal bandsaw use, this should not be an issue, just with veneering and possibly resawing to very close tolerances. Has anyone else encountered this problem and found a fix for it?

[ian maybury]

Hi David. I haven't done any grinding of bandsaw blades, but my experience is that some very highly regarded (marketed?) named blades from the US are not very well or consistently ground and/or the teeth set and/or welded - tracking problems can be an issue. Especially on saws that don't put enough tension into the blade to prevent it from deflecting under asymmetric cutting forces. So getting an improvement with regrinding isn't a great surprise. It's i seem to remember been reported before.

My best guess regarding your issue is that there's maybe more inaccuracy creeping in each time you grind - which could be compounding/compunded with original inaccuracies in the blade. (if any) I don't know how you are doing it, but for example if it's in situ and the blade isn't well supported it could very easily be inclined to either twist or bow away sideways while being done. Twisting might result in the faces of the teeth not being square/accurately aligned with the line of cut/the band. Bowing sideways could create variations in tooth geometry closer to the guides versus the mid section if it's not all being done at the same height.

Another possibility. If as seems likely the blade isn't highly tensioned it may be bowing sideways/generating sideways force while cutting anyway as a result of grinding, set or other misalignments. Add a top guide/guide post that's maybe not as rigid as it could be and it might explain the wider at the top deal.

It's even possible if there are inaccuracies in the set of the teeth side to side from new, and that nothing you do when grinding will fix it - although since you are doing OK on your first grind this seems less likely.

Perhaps the basic point is that lighter saws that don't tension blades so heavily must be sensistive to tooth inaccuracies - so a set up that tightly locates the blade band and the grinder to guarantee precision is likely essential.

Just in case - the other possibility is that perhaps (?) some inconsistency in the set up of your saw has crept in and is causing the problem - which the grinding is being blamed for...

[Larry Copas]

Each time you grind you remove a little set from the teeth. After your second grind there is not enough set to keep the band tracking properly.

I run a band sawmill and re-sharpen bands all the time. I usually re-set the teeth about every second or third grind. To re-set the teeth I use a setter with a dial indicator and try to keep my set within .002”. I'm not sure you can do that with such a small band. Inaccuracy introduced by sharpening with a Dremel would also play a factor after the second or third sharpening.

If band cost is too high the solution is a bigger bandsaw and run a carbide toothed band if you can stand the kerf loss.

[Jim Finn]

I find that carbide resaw blades outlast Woodslicer blades by a factor of about five and the ones I use are cheaper than Woodslicer . I pay $25 for a 105"x 1/2" resaw blade from "Supercut" It may be worth a try for you. I have not tried sharpening any blades.

[Lee Schierer]

In the old days, when people sharpened handsaws they would use a tool and re-set the teeth so the saw would track right. I suspect that you would need to do the same with a band saw blade to keep it tracking properly. Blade manufacturers probably have a tool that does this automatically as the blade is produced. I've never heard of an after market tooth setter for band saw blades, but perhaps a regular saw set could be used.

[Bruce Wrenn]

Instead of the Woodslicer, try a 1/4", 6TPI, hook pattern bi-metal blade. I think Lennox Diemaster is one brand. I buy mine from Woodcraftbands

[David Pascoe]

The consensus seems to be that I ground the set out of the teeth, which is what I suspected. I run the blade thru a jig to hold it but with the Dremel, can't begin to duplicate the set angle. Grinding the gullets instead of hitting the tops alters the set less. If I can only get one resharp, so be it. That's good enough, saving several hundred per year.

I have tried a carbide Lennox Trimaster and frankly, that blade scares the ***** out of me. It literally explodes a piece of cocobolo, blowing out the bottom of the board (3X that happened). It is far too aggressive for me and broke two of them after they burried themselves in the wood. The dang things would actually feed themselves. Scary.

The Woodslicer gives me a good glue surface where others I've tried haven't.

[Peter Aeschliman]

David, I've never done it myself, but it might be worth trying to set the teeth during the second sharpening. The hand tool guys do this all the time with their hand saws.