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I use a stationary disc sander for some of my building. I don't use it often and the adhesive on the discs often partially lets loose between sanding sessions. To be useful, the sanding disc needs to be absolutely flat, without any bubbles where the adhesive has let loose.To try to solve that I usually apply aditional contact cement to the discs, but that lets loose in time too. The additional contact cement gets pretty crusty on the aluminum disc and even with acetone or lacquer thinner as a solvent, it is difficult to clean off. I don't really want to have to apply extra glue to keep the dic flat, if possible. I currently have Grizzly discs, but have tried others, with the same problem. Being in Hawaii with it's high humidity may make this an unsolvable issue, but just wondering how others do with their disc sanders. Been struggling with this for many years. 15" disc size. Appreciate any input on on solutions, product recommendations, etc.-Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

I assume you clean the metal of the disc before re-applying a new sanding disc? Are you burning the wood when sanding?

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"Act your age, not your shoe size" - Prince

Might be your environment. My 12" disc sander stays at around 40% RH and the discs do not come loose, I often go several weeks without using it.

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Steve Smith
"Music is what feelings sound like"

I have a 10” disk sander. I use Klingspor disks. I usually have trouble getting them off. The adhesive has never failed but my shop is humidity controlled (40 - 43% and usually between 60 and 80 F). When I change a disk, I clean the goobers off of the metal with naptha.

Thanks for the replies. I expect it is just a humidity issue. it is not caused by heat buildup.The discs never burn. That's why I use a 15" disc so the heat dissapates better. I build in a dry room, but my power tools are in a non controlled room. Been dealing with the issue for 40 years, so I guess I'll just keep going. I don't actually expect a solution, but thanks anyway.--Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

At least you get to live in Hawaii Bob! I've had no issues with my 10" one for at least a couple of decades in much less humidity so as you think, it's likely something you have to live with unless RH is consistent in all areas of your shop.

I was gifted a 10 inch sanding disc by Simon Faye (Thank you Simon!) I keep the sander I built with it in a non environmentally controlled shop. I use 2nd hand Mylar backed sanding discs and adhere them with 3M spray 90. They stay stuck reasonably well. I think the Mylar (plastic) backing helps limit moisture penetration.

Just guessing here: The fabric or paper backing for the sanding disk would swell when it absorbed moisture making the disk somewhat bigger than at low humidity. That would cause some shear across the glue and bubbles where the backing swelled away from the metal disk. Being 15” in diameter makes the effect larger than for our smaller disks.

Same problem here. My 12" sander didn't do that when I first got it, I thought it was from buying cheap discs. But when I got some good ones it still did it. Maybe I need to try the Kingspor. It is in my climate controlled shop.

It is still very useful, but I have just been managing by touching everything up on a surface plate afterwards.

Pat

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Pat

What are your discs made of? Not the sandpaper, but the disc behind it? I built a 12” disc sander using a salvaged 12” disc from somebody’s old Delta, some shafts, pillow blocks, sheaves, belt and salvaged motor. The old Delta disc is steel. I’ve never had trouble getting PSA sandpaper to stick and stay stuck. But I do control RH in my shop.

My 12" disc is aluminum and I have to use naptha to get the sandpaper off. Of course, I always clean well with naptha before putting on a new disc too.

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Steve Smith
"Music is what feelings sound like"

The 12" disc on my Shop Smith has been my most frequently used power tool in my shop for many years. When I first started, ShopSmith sold a pure latex contact cement that worked great. It held tight under heavy sanding and when removing the disc, the latex could be rubbed with a finger coming off the disc cleanly, rolling up into a ball. But the contact cement was discontinued and I couldn't find a suitable replacement. Other cements would hold somewhat, but were a nightmare to clean off the disc. Sometimes I would have to scrub the disc with gasoline to get the stuff off.

I eventually switched to hook and loop discs which has a trade off. They last a bit longer because the are sort of ventilated during use, but they do have a slight rounding effect that has to be compensated for.

I have searched on the web for latex based contact cements but haven't tried any yet.

With the replies, it seems that humidity is the issue. No way I can deal with that aside from creating a new and bigger dry room which is not going to happen. The hook and loop idea is interesting, but the pieces I use the sander for can't have rounded edges. Thanks again for the help.-Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

I have found the best way to get the old adhesive off, after you have removed the old disk, is to turn it on and use a sharp card scraper on the table and gradually move it across from the outside of the disc to the centre. Gets all the crud off in a couple of passes.

I replaced a really old disc on my sander a couple weeks ago. Acetone and naphtha barely touched the residue adhesive, but D-Limonene worked like a charm. D-limonene is basically the active ingredient of Pure Citrus, Goof Off, etc. but concentrated. Plus, smells good, though lingers.

Dan- I've had he same issue. The normal chemicals used to remove contact adhesives did not work very well on my aluminum sanding disc plate. I have a number of citrus based products around here, as well citrus out in the orchard. I'll try some things. Thanks for the tip.-Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

Hi Bob,
The Mylar backed sandpaper -might- solve the problem if it is humidity related.
https://www.amazon.com/Sungold-Abrasive ... XHLW&psc=1
I've glued the hookit Mylar sanding discs to my 10 inch disc sander. Hookit is the opposite of hook and loop, so the sanding discs aren't as "furry"
These people sell Gem sanders and discs to go with them:
https://www.amazon.com/Sungold-Abrasive ... XHLW&psc=1

Thanks Clay. I did not see any discs large enough on those sites, but I'll check into it.-Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

I may have solved my problem, I hope. I removed, thoroughly cleaned the face plate, and applied a brand new disc on Saturday. By Sunday morning it already had bubbles under the sanding disc. I have been trying to come up with some idea about glue, or some kind of interface that might work better. So, I decided to try 3M #468MP Hi Performance Adhesive. If you are not familiar with that, it's the pickguard adhesive of choice. It sticks really good to anything and can be removed by rolling it off with your fingers. Naptha also softens it. I use it for pickguards, inlay, jig making, and applying labels among other things.You can buy various sizes of it on Amazon. Extremely useful for a ton of things. I bought a 6" x 180 yard roll of it in the early 70's and I'm on my second roll now. As far as I can tell, it never goes bad if kept dry. Large sizes, like the rolls I got are pretty hard to find. I had to call 3M and jump through hoops both times I got it. I got my last roll from somewhere in Kansas City that 3M told me might sell it to me. It's a pretty industrial size. Lots of small sizes on Amazon though. I buy 12" x 12" sheets there too. Anyway, I took off the new/used disc and applied the 3M stuff to it. It is holding absolutely flat like never before, but it has only been a day. Here's hoping it works. Gonna make radius neck and tail blocks today, so will report back.

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso