sanding discs

[Karl Best]

I've been having a lot of difficulty with the 2" hook-n-loop sanding discs that I've been using. After switching the discs no more than a dozen times the hook-n-loop on the base will no longer hold on to a disc. These are the wave shaped discs and the generic base that I got from Woodcraft. Is it normal to have to replace the base regularly? Certainly I should be able to get more use out of it than that. Or am I supposed to get a number of bases and dedicate one to each grit so that I'm not changing the discs so often? Is there a better system to use?

 

[Bill Boehme]

It sounds like you are overheating the disks by either applying too much pressure or running the sander too fast or the lathe too fast. Make sure that you aren't trying to sand with worn out sandpaper. Worn out sandpaper generates a lot of heat without accomplishing much work. Often we try to compensate by applying more pressure or sanding faster. All of these are things that will kill a H&L pad in very short order. Just let the sandpaper lightly float on the wood and also cut the speed way down. Most woodturners tend to be frugal about spending money on sandpaper, but we need to use sandpaper like somebody else is paying for it ... sandpaper wears out ... and much faster than we are generally willing to acknowledge. There are also interface H&L pads that can save wear and tear on the main pad. One last suggestion is to blow the dust out of the pad before applying another sanding disk ... the disks also need to be kept clean. My H&L pads generally last more than a decade.

 

[Tim Connell]

I use the "Roloc" bases from Wood Turners Wonders. I use a different base for each grit, primarily for speed. I use the mandrel, and a quick twist is all it takes to change grits. Ive been using the same bases for two years now with no problems.

Wood Turners Wonders also sells Velcro repair discs when you do need to repair the holder.

 

[hockenbery]

The only time I have ever had any hook and loop mandrel not hold was one that did some sanding without any disc in place.

Typical mandrels all go through many hundreds of disc changes before failing.
Failure is either separation of hook material from the foam or a fracture of the foam.

slow lathe speed medium to high drill speed light pressure.
If there isn’t a stream of sawdust coming off, change to a fresh disc.

 

[Karl Best]

Thanks, Bill. I was wondering if I might be overheating the H&L pad. I'll try to slow down. And thanks, Tim, for the product suggestion; I'll give that a try.

 

[Dean Center]

I have found that when the discs don't stay attached and I replace the disc with a fresh one, it sticks fine.

My theory is that the hook part has been used for a while and is a little worn. Then when the loop part on the back of the disc is also worn from the disc being used for a while, the combination causes the disc to release in use. The loops on the newer disc are better enough to stay on.

 

[robo hippy]

Like others have said, generally the interface pads last a long time, which is why we use them and not the main mandrill which costs more. The main thing that wears them down is heat. Most of the time heat comes from sanding too high speed, so low lathe speed, and with the angle drills, never more than half speed. Too much pressure. This generates heat. There is/was a practice for hand sanding where turners would use padding between their fingers and the abrasives. Fingers would not get hot, but the wood still did. Dull abrasives will also create more heat. Many times it is a combination of all of the above. I did have a few instances of 'cheap' abrasives where the adhesive between the abrasive and the loop part of the disc would come off, which was due to bad glue, and again heat.

Funny thing about sanding, slow speed cuts better than high speed. It is all about traction. If you are sanding too fast, the abrasives never get a chance to dig in and cut. I think it was Vince Welch of VincesWoodNWonders who first got that idea to sink into my head. I later heard several well known turners make the same comment. I did try those wave discs once. I prefer the blue over sized discs from Vince. With my warped bowls, I need my lathe to be down around 15 rpm, otherwise, I can't keep the abrasive on the wood. This can happen with hand sanding on bowls, especially if the bowl has moved even slightly. I made an articulated arm for when I sand. It allows me to rest my arm on the rest while I sand so the only work I have to do with the drill is squeeze the trigge. This allows me to spin the bowl with one hand, which is my preferred method up through about 180 grit. There is a video on You Tube about that. Articulated arm for sanding/robo hippy

robo hippy

 

[Dave Bunge]

One thing to be aware of if you're considering the "Rocloc" system: they only work with your sander running in clockwise (forward} direction. If you run the sander in reverse, the pads will come unscrewed. I run my sander in both directions so that was a deal killer for me. Otherwise, it's a very interesting concept (dedicate a pad to each grit, swap grits by unscrewing the old pad and screwing on a new pad) if you only sand in forward direction.

Dave