Belt Chatter Marks

[cedarghost]

Not sure if this is the place for this post or not.

Im having an issue with a couple of belts I just got in. They make a rhythmic chatter when I'm grinding on the platen. I was able to turn my grinder down with one of them to minimize it. The other I just had to toss out because they were putting marks in the blade.

I suspect "throw them out" and buy better belts is the advice I will get here as other belts don't chatter at all.

Safe to assume it is the seam in the belts and is there anything I can attach to the platen to minimize the chatter? 

Im going to buy better belts but I bought ten of the 40 grit, which is what I'm getting chatter on. Two so far. I'd like to use them but if they have to go I'll just chalk it up to getting what you pay for.

As always, many thanks for sharing the advice and wisdom of experience!

[ThomasPowers]

Are they lapped or butted?  In general buy better belts; but can you use them for slack belt grinding instead of platen grinding?

[cedarghost]

I can use them for slack grinding. In need to build a contact wheel attachment too. I think that would do ok. 

I don't know if they're lapped or buffed.  How can you tell?

[ThomasPowers]

Lapped: one end goes over the other end and is glued.  They only run at a single direction and will have a single headed arrow on the underside. They tend to have more of a bump to them in use. DO NOT RUN THEM BACKWARDS!

Butted:the two ends are butted with a thin bit of "tape" underneath the joint gluing them together. They run either way and so will have a double headed arrow on the back side. They have less of a chatter when in use.  Usually found in better belts.

[cedarghost]

Got it. I read "lapped or buffed". Need my glasses!

they are lapped belts.