conical disc sandpaper exploded

rdewinter · Post by **rdewinter** » Mon Apr 14, 2008 2:08 am

I was using the conical disc on some popular giving it a final touchup removing some saw blade swirls on the edge when all of a sudden a quarter of the paper came off and knocked the wood piece out of my hands. Wow, what a potential disaster that was. No one hurt. I put another piece of conical sandpaper on the disc and started to sand when this sandpaper tore off and again knocked the wood piece to the floor. Again no one hurt except my wood piece had a dent in it and there was a 4 inch gouge where it touched the spinning disc. Has anyone experienced this problem? Anyone have a clue what could have caused it? Sure don't like losing two sandpaper discs that run $16 each. BTW, when I install the conical sandpaper on the disc the split in the sandpaper doesn't close up entirely leaving about a 3/16" gap. Am I installing the paper wrong? How do I close that gap? The gap doesn't seem to affect the sanding? I really love this ss accessory because it gives great results once you master how yo use it. If any ss owner doesn't own a conical disc, you are really missing out on an outstanding tool.

Bob
San Diego, CA

Bruce · Post by **Bruce** » Mon Apr 14, 2008 9:52 am

Bob, you posted this twice so you'll want to check both for replies. My first thoughts are that you did not have good adhesion of the paper to the disk. This could be because the disk wasn't cleaned of oils, dirt, or old glue before applying the paper or the disk was too cold for the glue to adhere, or the paper was too old. I suspect one of the first two. I apologize if I'm telling you something you already know, but before applying new paper, clean the old glue and other impurities off of the disk with mineral spirits and wipe it dry. Then before applying the paper, be sure the disk is not cold. You can warm it slightly with a hair dryer or heat gun. You don't want it hot to the touch, just slightly warm. Lastly, press the paper to the disk with some decent pressure to activate the pressure sensitive adhesive. A roller of some kind would work nicely for that.

As for the gap you have at the seam, I think that is normal, although I didn't see any gaps on Nick's disk in his sawdust session. Humm... If you try to get the gap to close, I'm afraid you'll crinkle the paper and have ridges, which would be very bad. You want a purely flat surface. I hope this helps.

rdewinter · Post by **rdewinter** » Mon Apr 14, 2008 10:44 am

Thanks Bruce. All good suggestions. I like the improving the adhesion suggestion by using a roller. That may be what happened the second time. The first time I was using a previously used disk. When it tore apart it sure was scary.
I also learned a lesson the hard way. I got my fore finger too close to the spinning disc. I touched the spinning sandpaper while trying to hold down the piece. The conical disk won!! After I got the bleeding stopped, I discovered I now have a very smooth divot in my finger. Lesson learned....a) don't touch a spinning sandpaper disc, stupid and b) maybe wear a tight fitting glove just in case I do.
BTW, after putting the third $16 sandpaper disc on, I was able to sand several pieces without problem.
Anyone found conical disc sandpaper at a more reasonable price or has anyone seen ss put the paper on sale?

Bruce · Post by **Bruce** » Mon Apr 14, 2008 11:05 am

As a matter of fact, the Sanding Sale is going on right now. I don't know where you bought your current supply, but if you paid $16 per disk, you got ripped off. Even SS's regular price is only $18.59 for 3 disks. Right now they are on sale for $14.87. Here's the link.

kalynzoo · Post by **kalynzoo** » Mon Apr 14, 2008 11:47 am

I had a similar problem, with similar results, the wood being kicked out of my hand. I cleaned the disk with mineral spirits. After it was dry I sprayed it with the pattern adhesive spray...I use DAP but 3M also has a tacky spray. So far its worked. Now if SS would send the back order on the sanding discs I could play with it more often.

Nick · Post by **Nick** » Mon Apr 14, 2008 3:46 pm

Drew and I also experienced this problem when we fist tested our thicknessing jig. The problem was that we were in a hurry and did not wipe the disc down with a solvent before applying the abrasive. Incidently, we use naptha instead of mineral spirits -- slightly more powerful solvent and it dries more quickly.

And by the way, there is a gap on our discs.

With all good wishes,

timster68 · Post by **timster68** » Mon Apr 14, 2008 5:32 pm

Nick wrote:Drew and I also experienced this problem when we fist tested our thicknessing jig. The problem was that we were in a hurry and did not wipe the disc down with a solvent before applying the abrasive. Incidently, we use naptha instead of mineral spirits -- slightly more powerful solvent and it dries more quickly.

And by the way, there is a gap on our discs.

With all good wishes,

Can you get Naptha at say Ace hardware or something similiar?

timster68 · Post by **timster68** » Mon Apr 14, 2008 5:34 pm

One more thing, would Naptha be good at getting the goo off the bandsaw tires (going to put Urethane on real soon) I printed out the earlier discussions of removing old tires but hadn't heard of Naptha before.

Bruce · Post by **Bruce** » Mon Apr 14, 2008 8:06 pm

I believe that Naptha is more flammable than mineral spirits, so you might want to take that into consideration. At the very least, wear solvent proof gloves when handling it in a well ventilated area.

cincinnati · Post by **cincinnati** » Mon Apr 14, 2008 8:42 pm

timster68 wrote:Can you get Naptha at say Ace hardware or something similiar?

They should have it. Also Home Depot or Lowe's. Comes in a qt. can most of the time.

http://www.danforthcenter.org/taylor/te ... naptha.jpg