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Failure: sanding pads

Owen Lowe

Owen Lowe

Joined
Oct 25, 2005
Messages
935
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243
Location
Newberg, OR: 20mi SW of Portland: AAW #21058
Help, my backup pads and interface pads are always coming apart! It’s not the Velcro that’s failing; it’s the foam that’s pulling away or deteriorating from the hard plastic and Velcro. Actually, I think it’s the Velcro that’s causing at least half of my problems. It’s some tenacious s…t! Occasionally, it grips so tightly that it pulls the soft fuzzy side off the back of my sanding disks. I have 2” and 3” pads with both the regular Velcro hooks and the micro-hooks — doesn’t seem to matter… and these are not old pads (I seem to buy a few each year). My interface pads breakdown at each side where the velcro attaches to the foam. The backup pad breaks down where the foam is attached to the plastic arbor.

Maybe the yellow-foam $7-10 sanding pads are the “cheapies” and I need to spring for the $20-30 pads? Maybe I need to get 5 or 6 backup & interface pads and dedicate a grit to each? Maybe I need to make my own?

If making my own, what is considered an excellent wearing, medium density foam and what glue for attaching it to the arbor?
 
I have had problems with the micro hook and loop pads and discs pulling each other apart. I learned to slip my finger under an edge and gently lift the disc off by sliding my finger under them rather than ripping them off. That helps. Other than that, the firm and medium pads last much better than the very soft foam ones which seem to fall apart just because they are so soft. I use firm backing pads up to 220 and then the medium pads. If I go beyond 400 grit, then I go to the soft pads. The discs seem to cut way better in the coarser grits if they are on a firm pad, and when you get to the polishing stages, then the soft ones are the way to go.

robo hippy
 
Similar to Reed, I grab the hook side and the loop side with the thumbnails sort of facing each other and pull gently at first. This works pretty well.
I have been pleased with the pads I get from sanding glove. The soft pads aren’t as strong.
 
I went a different route, sort of. I purchased pads for every grit so I don't have to pull the sandpaper off as often. I purchased my last ones from Vince's Woodnwonders and have been very happy with them.
 
Saw this video on youtube and had to try it.
View: https://www.youtube.com/watch?v=G44HICpHgqg

Used HF hex bits with point ends ground off and quick bit holder, knelling pad and velcro from HD. Used a hole saw to cut both wood and pad.Velcro could also be gotten from Vince). The best part was the quick attachment chuck for the discs. I found that without having to change disc the velcro seems to hold up better. And the knelling pad seems to hold up well. I found this method worked better than changing sanding disks.
 

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Bob, is that like a yoga mat or garden pad you’re talking about?
 
On the hook side, I sand off the hooks on the first 1/16th of an inch (circumference) . Seems to help keep the velcro from pulling off the pad. Like others have mentioned, thumb nails help...
 
Have you considered that you may be apply in too much pressure or having the speed to high on the spinning disc? Those two factors can cause an early demise of the backing pads, and velcro. I have had the same thing happen, but as I've learned to slow the sanding and less pressure against the wood, the sanding usually is better, easier, the abrasive cuts better, and I get the project done more quickly with better results all around.
Of course that may not be the issues with your particular setup....it might be the pads or mandrels. You did not mention what brand you use, but they are not all equal. I use mostly the ones from Vince's, but seems the ones from Klingspor do work well also. I have had some I got from our local club that were not the greatest, but what I got from Vince seems to last longer.
 
I do similar to what Bob said. After mounting the wood on the hex bit I turn it down on lathe and attach foam with SHoe Goo. I have found Kaizen foam to be the best the kneeling pads just would not hold. Once the glue sets up turn the foam to shape on lathe and glue on hook pad with same glue. I do use a interface to save the hooks and this method along with using different mount for each grit makes these last much longer
 
I agree with Roger. Heat from too much pressure and/or too high a speed is almost always the culprit. Also, open cell foam does deteriorate with age. I was making my own sanding disks and had some foam sheets that were several years old and just turned to mush when I tried to cut them into disks. I now just buy them from Steve Worcester and they seem to hold up reasonably well.
 
I only use the soft ones with finer grits, they seem to just fall apart if not... The medium soft ones are easy to glue back together, impossible to fix the soft ones... Overall, they are a minor expense, I just buy lots of them, they are disposable like the paper...
 
Thanks everyone. I am an adherent and proponent of slow-speed sanding, so I don’t think the failures have been because of overheating. (Early on I certainly burned the hooks off of pads, so I’m familiar with too much speed.)

I’m wondering if it’s more caused by the inside bowl shape and deforming the foam too much. I make quite a few bowls with inward curving upper walls - kind of comma shaped. I think this might be why the foam is separating from the hard plastic of the arbor. It’s flexing an awful lot to get that curve where the wall meets the bottom. That and the overly tenacious Velcro might be the downfalls for me.

One of my longest lasting back up pads has the whitish foam and is still doing quite well; the yellow pads just aren’t. I prefer not to say where I have been buying the failing pads and I think I’ll try the Sanding Glove version. Or, make my own, so thank you for the assembly tips.
 
Owen,
I have had exactly the same problems and ended up discussing it with Vince Welch. He was certain I was applying too much pressure. I can't seem to change my ways, so then he suggested the very thin, firm backup pad. And to keep trying on the pressure.
 
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