Since the motor mandrel with the Beall system takes a 3/8” bolt I’ve made several sanding mops.
First was a 320 grit for finish sanding in general. That worked well enough so I made a couple in 220 grit, a thick one and a thin one.
This past week I started making a mass production of challenge coin holders and decided I needed to up the game on the sanding mop. I wanted to sand the 2 1/2 inch wide holders in one pass. So I needed a sanding mop at least 3 inches wide.
I looked at several youtube videos of folks measuring, cutting, punching, and that seemed nice.
But after a couple of years of using a mop made out of square pieces of 4” sanding belt I decided to throw caution, and accuracy, out the window and go bigger.
I went to my local American Maintenance Suppliers (a real garage man-cave store) and snagged a half dozen 3/8×4 bolts, and a bag (50) of 3/8×1 1/2 inch fender washers.
(Parenthetical: A few months ago I made the score of a lifetime on sanding supplies, about 40 (forty) 36×60 sanding belts for $40. Each belt is the equivalent of about 24 full sheets of sandpaper. I got grits from 80 to an unbelieveable 40 microns. The sandpaper mentioned is from this score.)
I dug out a piece of 120 grit sanding belt and was just getting ready to rig up an impressive measure and tear jig when it occurred to me that about an hour after I started using it the whole neat and symmetrical thing would be shredded into a roughly circular shape. So I unrolled it off the end of the workbench and used the edge of the bench to tear it into strips.
Not exact measurement, just roughly 4 inches in width. Some strips were closer to 3 inches others were more like 5. Then I made a mark about 6 inches from the edge of the bench and tore the strips into rectangular pieces as long as the mark.
Since the belts had been tightly rolled by yours truly after I got them home they had a very tight curl. Rather than try to flatten them out and get them all square and true I grabbed small handfuls and went to the drill press and drilled 3/8 inch holes in the rough (eyeballed) center of each stack. Since they weren’t completely aligned in the stacks some of the holes were more off-centered than others.
Back to the workbench. 3/8 bolt with 2 fender washers on the end. Then a simple process: two of the pieces of sandpaper back to back on the bolt then a fender washer…repeat at 90 degree offset until the bolt was full. Then 2 more fender washers and a nyloc nut to hold it all together.
I ended up with a sanding mop about 3 inches wide and 7 inches in diameter. It worked like a charm with one exception. The 120 grit was a little too aggressive for the finish I wanted, so I took another 30 minutes or so and made one in 220 grit.
I got to work and sanded 400 LINEAR FEET of 2 1/2 inch wide hardwood in about 3 hours. (The bottom box is FULL.)
Here’s a piece before sanding…
And the same after a couple of passes over the mop. Note how the edges are softened and the saw marks smoothed out.
Sure enough the square edges of the mop rounded off.
Later on I’ll make some in 80 and 150 just to round out the stable.
-- Pete, "It isn't broken, you just aren't using it right."