Sanding Discs
I’m not going to discuss actual sanding here. You can watch the videos for details, okay? If anyone has a specific concern/question not covered in the video I could be coerced into adding more info. here!
See my two videos on Sanding: Video one and Video two. I discuss hand and disc sanding in them. I would also like to state that I no longer purchase the “red adalox” that I talk about in the video because Rio finally carries the sticky backed Aluminum Oxide discs. It’s not that I hate the paper backing but, I really dislike it. They don’t last long, tend to fall apart rather quickly and are ugly. It’s a personal problem.
If somebody, out there, would just make a flexible, plastic disc, that came in all grits I wouldn’t have to go through this song and dance. But, alas…… Anybody out there listening? Like 3M maybe?????
Disc sanding supplies
3M now carries a pretty full line of aluminum oxide sanding discs; ranging in grits from 180 to 1200. They come with a sticky back and are intended to be used with their mandrel, which is hard backed. 
I find the hard backing difficult to work with and really like the flexibility available with my method of using the PSA Quick Change Sanding Discs. The big difference between the two types of discs discussed is that one has a square-ish shaped brass hole for the mandrel and the other has none.
Here’s the mandrel (close-up) for the Adalox and Moore’s disc.
A brief note on these mandrels: occaisionally the head gets squished shut and the disc spins around on it. Not a good thing as no actual sanding is getting done. So, take the disc off, get a small slot headed screwdriver, and wiggle it down into that split there. Don’t over do it, sport – just a little bit. Check the fit of the disc now. Ah, so much better, eh?
So, generally I use Moore’s Sanding Plastic Discs with the 3M PSA Quick Change Discs but I’ve found that the Adalox discs that Rio Grande carries, works as well (not the red one pictured on their site). I imagine that any plastic disc would work. If you have some other brand, try it. Ya never know!Now, I can get all my sanding supplies from one place. Yeah! 
Moore’s from Otto Frei.
Adalox Aluminum Oxide from Rio.
So, now for the song and dance you’ve all been waiting for:
First, take the used (or new) Adalox or Moore’s disc and turn it over so the backside faces up. (I generally use, used disks, as I get double usage out of them).
Next, pull off a 3M sticky backed disc in the grit you need. Carefully, center the sticky disc to the back of the Adalox or Moore’s. 
Next, you need to cut a little “X” through the sticky disc so, flip the disc back over (the new back side), pull out an Exacto blade and cut from one corner, of the brass mandrel slot, to the other. See the image below.
We do this to allow room for the mandrel head to pop through. Otherwise, it doesn’t fit the mandrel properly. See? (Look Down).
That’s it! Pretty easy and now you have a flexible sanding disc. You can also use the mandrel that comes with the kit but, you also have to buy the kit. Could be what you want, then again maybe not.
