I had an occasion to modify my H.F. ElCheapo angle grinder into a disk sander that the former Bush administration would've classified as a weapon of mass destruction due to it's aggressive nature. I bought this adapter for it:
http://www.harborfreight.com/5-inch-backing-pad-fo
It was only $3 'cause I had one of those 20% off coupons found in Wood Magazine's advertiser pages. I also had a supply of c- weight sanding paper remnants- I buy an assortment for $20 per 10 Lb. box, so my per 5" disk cost is only a few pennies. I proceed like so:
With a compass draw a 5" diameter circle, followed by a 2" diameter, and finally a 3/4" one. Cutout the 3/4 arbor hole and pie slice out to the 2" circle line, this allows the retaining washer to nest below the pad's surface.
Now go and find a surface that needs to be hogged down in a hurry, this is not a fine finish tool, but if you need to quickly knock down a glueup surface or renew a workbench top or grind a stump, this is the beast that will do it fast. Be advised that with no dust collection, this thing spews out the dust, so use outdoors or over a powerful sanding suction box.
