Breaking Sanding belts

[LCHIEN]

I have a Ryobi 4" belt 6" disk sander.
Fired it up today when it was 43 degrees in the shop and the belt broke.
replaced it from a box of belts I ordered way back and it broke when started. Replaced another and it broke immediately on startup.

So the belts 4" x 36" are Nortons. The copyright date on the cardboard sleeves says 1997 but I didn't start woodworking until 2000 so I doubt they'd be before about 2003 as the copyright date is not indicative of date of manufacture, just the package design.

So the belts are all breaking at the diagonal joint, there is a strip of tape that pulls off of one end, after a couple of rotations. I'm presuming that 10 years old, the adhesive is dried up? I don't think the cold has anything to do with it?

I have more but I figure after 3 there's no point in trying.

Is there any hope of repairing these with new tape? What kind of tape? Looks like a fiber tape, the adhesive would have to have a pretty good shear strength due to the tension on the belt.

These belts are butted and taped, not overlapped and glued.

[Cochese]

There's not too much tension on it?

[LCHIEN]

don't have any reason the tension would have changed in all the years I've had the sander. Seems to be reasonable when I close the tensioning lever.

[Cochese]

I think your reasoning about the glue is probably true, but I do wonder if there is any shrinkage that happens with that kind of material.

I'm just spitballing, I don't have much experience with belts. Even on my OSS I rarely use it.

[leehljp]

Not an expert on this but from experience with observation and not so scientific logical deduction: Numerous seasonal humidity changes breaks down the glue. I have some 6 in belts that still work fine after 20+ years, but they stay in a thick cardboard box. And I have had some 3 inch that came undone after setting up for about 6 or 7 years and then putting on my makita sander. My 3 inch belts were not boxed like the 6 inch belts.

These are belts that started out here in the states, went to Japan and came back with me 3 years ago. I took the 6 inch over in 1989, and the 3 inch belts around 2001.

(HF belts on the other hand did this when new.)

[rcplaneguy]

My dad stockpiled (new at the time) sanding belts in the 1990s. I inherited them and recently tried using. Every one failed almost instantly at the diagonal joint. I tried regluing a few but was unsuccessful. After breaking 20 of them I went to Lowes and bought a new one. The new one has worked perfectly for many uses. The lesson? Toss the old belts.

[LCHIEN]

I think your reasoning about the glue is probably true, but I do wonder if there is any shrinkage that happens with that kind of material.

I'm just spitballing, I don't have much experience with belts. Even on my OSS I rarely use it.

I think the shrinkage is minimal. The Belt sander has a spring loaded tensioner that depends upon a spring, springs with age get weaker if anything but not tighter. BUt anyway the spring looks to have a travel of about 1/4- 1/2" to take up the slack.

[LCHIEN]

My dad stockpiled (new at the time) sanding belts in the 1990s. I inherited them and recently tried using. Every one failed almost instantly at the diagonal joint. I tried regluing a few but was unsuccessful. After breaking 20 of them I went to Lowes and bought a new one. The new one has worked perfectly for many uses. The lesson? Toss the old belts.

I think you're probably right but my sense of cheap tells me to try and fix them.

[LCHIEN]

I'm gonna say this:

One layer of duct 1-3/4"" tape holds for about 30-seconds. With the tape applied perpendicular to the joint and trimmed on the edges.

Same thing, but with two pieces of 5 inches of duct tape applied side-by-side and in-line with the belt on top of the first piece of duct tape holds at least well enough to sand for about 4-5 minutes.

So in an emergency repair, duct tape is a possibility. I left it tensioned so we'll see if its still holding in the morning.

And yes, the old tape peeled off the remaining side like, well, old dried up tape. Very easily. So it must be age and temperature cycles.

I got what I wanted to sand done w/o a trip to the store. Some new ones are on the way from Amazon via 2-day delivery, due Monday (tomorrow being thanksgiving).

[rcplaneguy]

Yeah, some of 'em were 3" wide belts for a sears sander and some were large 6" wide belts for a Shopsmith sander. The glue fails with age, trying to keep the old ones going was too annoying after a while.

[tohellwithuga]

A couple ideas from http://www.practicalmachinist.com/vb...-belts-184777/:

I have finally had success with making belts and re-gluing old belts with Gorilla glue. I picked up a large quantity of 1x48 belts at a sale that were older and the joints were failing. My method is to take a single edge razor blade and remove all traces of old adhesive from the joint. I then align the belt ends using a piece of aluminum angle.
Then I wet the canvas backing slightly and apply a thin coat of Gorilla glue to the joint area and clamp them together using a small Teflon block on top of the seam and apply pressure with a c-clamp.
The glue expands into the wet joint.

After setting over night, I scrape the excess glue away that has expanded out of the joint and use the belt. I have not had one break as of yet or a least not until it is worn out!
I can make custom belts from shop rolls when I need a finer polishing belt. It works for me but your results may vary.

The perfect "tape" for gluing over the joint appears to be Tyvek. You know that cloth/paper type stuff that they make priority mail bags out of. I happen to have a roll of it left over from building the house, but the mailbag is the same stuff. Can't tear it, is highly flexible, and presents a cloth to cloth glue joint. No more plastic strapping tape and fighting the adhesive that has to be removed before gluing.

[Stytooner]

I think the reason duct tape fails pretty quickly is due to heat. Just friction from the rollers and platen would likely be enough even without any sanding.

That Gorilla glue idea has merit too.
I haven't had any standard belts break on me. I use a lot of them and they rarely get more than a couple months old.

You would want something that is not heat sensitive when cured and that is pliable with some give while remaining adhered. Probably a secret sauce well known to manufacturers, but closely guarded and readily available at industrial suppliers.
Mcmaster Carr has a very large selection of industrial adhesives and epoxies, but you would need some really good stuff to glue your lower jaw back in place after seeing some of the prices for those.

I have recently tried some of the HF belts and I have to say I am really impressed with them.
Price is very low, but they work very well on stainless steel and oak.
Last quite a long time too.
As long or longer than some of the Norton's I usually buy. Someone must have tipped China off to the secret sauce.
I use mostly 6" x 48" and 1" x 30" and lots of them. Buying belts doesn't hurt nearly as bad as it used to and I find that since I am not quite as frugal with them, the jobs get completed faster, which in turn saves too.

[greenacres2]

I got about 20 when I bought my old belt/disk sander--went through 3 or 4 not lasting more than a few seconds and ordered new. I kept them, great for making sanding blocks and non-slip jig surfaces. But--I've wondered about trying contact cement and/or Gorilla glue. Haven't gotten around to it, sounds like there may be hope. For sure I'm going to use up the ones I bought new first, no point in wasting them too!!

Definitely don't throw them out Loring, they are beefy for sanding blocks.

earl

[greenacres2]

Just did my morning spin on CL--this guy mentions the box of belts like a selling point. Any bets on how long the first one would last??

http://southbend.craigslist.org/tls/4217612979.html

earl

[cwsmith]

I'll go with the thoughts on "old". Things just age to the point where they've lost their integrity, IMHO.

Fixing sounds like the way to go, as I too would view the many breakages as 'such a waste', expecially considering it was just the seam.

I have never used it, or owned it, but what about Gorilla TAPE? Is it too thick to use?

Also, is there any value in trying to contact the manufacturer of the belts. They may well have a suggestion.

Happy Thanksgiving,

CWS