Thread: Linisher belt joint types

Thanks for the heads-up. I'm about to buy some more belts. The H&F blue belts I got last time have mitred joins.

That sounds a bit nasty! I have used the lapped and glued as well as the butt spliced with tape. Some times they rip a bit making a huge flap wheel effect. I can't say a have had a belt part at the join yet but my belts don't last that long anyway as I am quite hard on them.
I keep some of the worn belts for polishing but I'm usually going a lot easier on them at that stage.

I have been told that humidity really effects the bond. Sometimes it's the manufacturing process that did not work out just right. Maybe they had the new apprentice joining the belts that day!
25 years without a whip injury happening is pretty impressive! I tell everyone that comes to my workshop that the belt grinder is called the "thumb puller".

When you say scalloped type join, do you mean it looks like it has been cut with pinking shears like a sine wave?

I have seen these belts advertised and always thought their was far too much edge that could lift during grinding. But there is a lot of money stitched up in developing and testing abrasive technology. I'm just an end user!

i have had these break and ran out the door to switck power off in other part of shed! have found in tropics belts need to be fresh. tried some thin super glue on a couple of joins and they lasted really well cheers Bob

Originally Posted by Ben Dono

do you mean it looks like it has been cut with pinking shears like a sine wave?

Thats them!

My mate has some 100mm wide ones with the same lap and they have let go. He was saying you sometimes get a second of warning as in a noise pitch change. I got no indication of an imminent fail.

I don't have many of the scalloped type but the ones I had were fresher than the miter joins.

I"ll stick with the miters from now on.

The same type belts(at work) have failed one after the other.Who knows, maybe we had a a bad run of them, but I thought it well worth a heads up if it saves someone and injury.

cheers
Grahame

Grahame,
this is a common problem with all the "modern" belts. I have usually used the lapped belts, but they are not available in small quantities any more, and I have been having a lot of failures with the tape joined ones. (catching when doing sheet metal). After a vigourous discussion with a Sydney supplier, about the quality of the joins, I tried an experiment with using Weldbond Professional Wood Glue but you can use any good alternative. I got some new belts and ran a glue line accross the join each day for 3 days, let it harden and hey presto, no more breaking belts. They now run out of abrasive coating first.
Hope this helps,
rgds,
Crocy.

Thank you Old Croc,

I have some weld bond somewhere.I certainly intend on giving this tip a shot.

I date my belts when new and most don't seem to last better than 12 months whether I use them or not.

thanks
Grahame

Originally Posted by Grahame Collins

Thank you Old Croc,

I have some weld bond somewhere.I certainly intend on giving this tip a shot.

I date my belts when new and most don't seem to last better than 12 months whether I use them or not.

thanks
Grahame

I made the mistake of buying a box of 10 once, and they all fell apart, so now I buy them 2 at a time from Blackwoods, glue em and have not belted my thumb since. I thought it was the heat or humidity here in Townsville, but now I am convinced its just cheap glue or tape.

Let us know how you get on,
Crocy.

Some great tips guys! I'm going to try out the weld bond and super glue trick.

There is a tape you can use for a temporary bond. I noticed it on one of the websites in the states. It's for pipe and railing workers polishing after they have welded and installed the product. They join the belt around a railing and use a little grinder with a wheel to drive the belt.
There is another guy on YouTube that uses single sided fiberglass carpet tape!

You run the risk though. Splitting belts can be nasty!

At times I have asked the suppliers about repair tape for the belts and they usually back away from the question pretty fast. I would say for the most part it's an OH&S issue.

The weld bond idea sounds great. I do sometimes inspect the joins on old belts before I run them. The ones that let go usually have started lifting away from the tape bond.

Have had plenty of experience with belts in manufacturing/jobbing environments with belts and belt failure, but luckily all with polishing lathe setups. Similar to a 5-10HP stand mounted grinder with long shafts and 2.5m belts. The joy of these things is that your work positions are well offset (600mm +) from the motor, and when a belt splits or lets go, you normally get enough warning to step toward the motor and out of the way of the flapping belt before it becomes too hairy for comfort. Once clear of the belt path, you have access to the primary power controls and estops.

The long belts mean that belts don't wear as quickly, but go a lot faster, and have a lot more material flaying around if they fail. Working with canvas contact wheels means you get much more 'feel' for belt problems developing and can normally stop and change belts before they split or let go.

That said, in that sort of environment, fresh belts come from the wholesaler on a weekly basis and are often in the skip by the next week anyway, so join degradation is less of a problem. But, you soon learn to take the tension off the belts even for short periods of inactivity such as meal breaks, so they don't sit stationary under tension for long periods as might happen with a lot of grinder/linisher conversions.