Problem with Sanding Disc?

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Locobreath

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Apr 7, 2004
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Guys: Can you figure this one out?

I have a Jarmac 4 inch sanding table which I bought back in 1997. At that time I bought a few packets of the sand paper discs along with it. About one year after using the machine, I noticed the discs no longer adhere too well. They buckle and starts eating into the aluminum miter plate. I tried using another disc. When I peel off the paper behind the disc, I feel there is still adhesive and it sticks to the aluminum wheel but soon comes off after just minimal use sanding. I haven't used the machine now for a couple of years and took it out just a few days ago and tried again. The same problem.

I went to the hardware store near me. He told me to clean the aluminim disc with solvent to remove the glue that remains after a disc is removed. I tried this. The glue does not come off and I have the same problem.

I am still trying to use the original packets of discs that I bought with the machine. Do the discs lose gripping power over time? Is this the problem, not the fact that there is some minimal dried adhesive on the aluminum disc? :confused:

What should I clean the wheel with to remove the deposits of adhesive? Do I need a newer batch of sanding discs? Would that do the trick?

Thanks guys. :confused: :confused: :confused:
 
I don't know if it will work, but at the autoparts store get a tube of sanding disk adhesive and try that. Body men use it to stick sanding disks on DA sanders. Should work but no warranty. LOL Fred
 
Ha Enjay, Sounds like the adhesive on the paper has gone bad. You could try using a solvent to soften the adhesive. Or the stuff Fred mentioned should work fine. Also 3M makes the same stuff that comes in a spray can and is easier to deal with, although you will likely have to get it from a automotive paint supply store.
 
Try cleaning with ascitone, works well for cleaning, a whole lot cheaper, get it at auto body and paint store, also get new sanding pads. I have a Sears hobby sander with triangle shaped cushion head. ascitone worked well for me.:thumb:
 
dont buy the disks with adhesive on them. It sounds like you dont use the machine offten so buying a whole pack of pre-sticky disks isn't a good idea. buy the disks without adhesive and get the spray adhesive, after spraying the disks give it like 2 mintes to set up, they should have no problem sticking after that.

As far as cleaning the metal disk, use ascitone.
 
Thanks again guys:

3phase: You're right. I don't use the machine often enough. When I got the machine it came with a disc already installed. It lasted for about one year. Once I tried to replace it I had no luck. I think they gave me old packs of discs to start with. If anyone is interested the machine itself does a great job. I use it with a dremel rheostat and get a full range of speeds.

I don't think jarmac makes discs without adhesive. I've looked in Sears for alternatives but I didn't see any 4 inch discs. That's one of the problems with buying small, hobby sized tools. I'll look for 5 inch and see if I can cut them down.

My local hardware man told me to use denatured alcohol. It didn't work. I'll try the acetone.

Matthyro : What is the brand for the contact glue cleaner?

I have a small bottle of Goo Gone. I haven't used it because it will probably leave an oily film on the disc.
 
Fix it fast with lacquer thinner. That will melt anything off the disk. Watch out for that stuff though. Use the proper precautions, it's volatile stuff. I use it quite offend to do the hard work. A small can goes a long way. If your considering rubber cement thinner, well, that's basically a high grade lacquer thinner. I use lacquer thinner to thin out my rubber cement all the time and it works fine. :thumb:

Dont give up on those old disks. This is what it sounds to me like is going on. You have residue glue build up on your disk. What that will do is create high spots in your sanding disk when you stick a new one on. The high spots will get hotter faster due to the uneven pressure. The heat melts the glue and the problem gets worse. Clean off all the residue and try a new sanding disk.

Make your own sanding disks. I do all the time. Bye the sand paper in large sheets. Use a compass to draw out your disk on the back of the sand paper and cut out with an old pair of scissors. For best results cut the disk 1/4" too big. Use a spray adhesive, like 3M's 90 or 76 to stick the sand paper to the disk. Contact cement would work too, but its a little more tricky to get an even coat, although there would be less mess than the spray type glue (it has over spray that can be real trouble if your not careful) Once the sandpaper is adhered to the disk then true up the edge with a scrap of sand paper left over from cutting the disk. Do this while it spins at high speed and it will smooth out the balance. To change the sand paper. Rip it off or cut it off with a knife, being careful not to damage your disk. Then clean off the excess glue with lacquer thinner.

I like to have over-size disks by just a bit because it gives me a softer edge that is good for some forms of shaping. :cool:

One thing more, that I have done in the past. Seeing as how it would take to long to clean off the disk and glue a new one on, I have just glued one sand paper disk right over the spent sand paper. As long as the old paper isn't torn, this works quite well and speeds up production. I have had them up to 8 layers deep with no problems. You can do this if you make your own sanding disks, because the high strength glues, like 3M's 90 and Contact Cement, hold so much stronger than the commercial sand paper disk adhesives.

Try this all out and tell me what you think. :confused:

TrainClown :wave:
 
Thanks everyone for the fine suggestions. I think I solved the problem.

I noticed that the Jarmac discs are very thick and hard to bend. (heavy padding). When I bought them they were not flat- but distorted.( Is it possible that the distorted shape was due to the drying adhesive?). When the disc was on the machine the tendency of the discs were to pull away from the aluminum plate (to return to the distorted shape). I really think the discs were just no good even when I bought them.

This weekend I went to Menards, a large hardware chain. I bought 3M sand- paper sheets (4 1/2 x 4 1/2inch) (thin sandpaper) with adhesive backing. I used the old Jarmac disc as a template and cut them with scissors. I removed the adhesive backing and it stuck fine. It's been on the machine for two days now and works very well. For $1.98 for three sheets, I can affored to use them even if i don't use the machine a lot. I noticed that 3M sells an adhesive remover for their products. I will buy some as soon as there is an adhesive build up. So the adhesive residue is probably not the problem.

I still have some old adhesive on the aluminum disc. It will have to be removed at some point soon. Denatured alcohol did not work. (recommended by the hardware man.) I'll try the lacquer thinner next. I'm a little put off by the health issues. That's why I no longer use Floquel. But for now the sander has come back to life and I'm using it a lot.

One other question: To bypass the use of chemicals I thought of using my soldering iron on the adhesive and then using a putty knife to scrape it away. Would it work? I'll try it and let you know when I do.

Thanks again all.

Trainclown: Good detective work. :thumb: :thumb: :thumb:
 
Locobreath said:
Thanks again guys:

3phase: You're right. I don't use the machine often enough. When I got the machine it came with a disc already installed. It lasted for about one year. Once I tried to replace it I had no luck. I think they gave me old packs of discs to start with. If anyone is interested the machine itself does a great job. I use it with a dremel rheostat and get a full range of speeds.

I don't think jarmac makes discs without adhesive. I've looked in Sears for alternatives but I didn't see any 4 inch discs. That's one of the problems with buying small, hobby sized tools. I'll look for 5 inch and see if I can cut them down.

My local hardware man told me to use denatured alcohol. It didn't work. I'll try the acetone.

Matthyro : What is the brand for the contact glue cleaner?

I have a small bottle of Goo Gone. I haven't used it because it will probably leave an oily film on the disc.
Click to expand...

Brake disk cleaner will take the oiley film off if you get that.
 
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