What grit on a disc sander

[Dan Oelke]

So I have my new 12" Disc sander - and so far it works pretty well. It came with a 60 grit disc. Very agressive - I can round off the end of an oak 1x2 into a semi circle really fast. I am planning on having my 10 year old son use it to clean up some rounded ends cut with the scroll saw. As such I was thinking a finer grit that would leave a surface requiring less sanding would be good as well as having something a little less agressive so he has better control sanding up to the line.

So I looked a little at discs on line and in the store, but really dont know how fine I want to go without having to worry about being too fine. What do you use or what do you recommend?

I have found that Industrial Abrasives sells a hook and loop pad and 12" hook and loop discs. Their hook and loop discs are pretty inexpensive. This way I could switch until I found something right, but it also means spending $13 for the hook and loop pad, which I could just as easily spend on a couple of PSA discs. I'm also a bit worried that on something like a large disc sander the hook and loop would wear out pretty quickly and/or provide too "soft" of a surface to square a board end against. Do you think the hook and loop is a good way to go or crazy?

[Jim Becker]

Since these tools are pretty much for shaping wood, I only use 80 or 100 grit on them...usually just the 100.

[tod evans]

dan, i keep 40-50 grit and on occasion 24 grit on my 12", anytime i`m using it i`m getting stuff outa the way, not trying to finess small items. for finess i use an edge sander..02 tod

[George Summers]

I keep 80 grit on both of mine (an 8"/1" belt and a 9"/6x48 belt). As said before, it is primarily for roughing. I use the 1" belt for smoothing. I can get belts up to 220 at least, I've not looked for finer.

George

[Bruce Page]

Dan, I have a 12" benchtop with 180 grit & a 12" stationary with 80 grit. I use the 180 grit the most.

[Doug Shepard]

Usually 80 or 100 on mine too. I for one think the hook and loop pad might be worth the bucks though. There might be occasions where changing to a finer grit would be called for. Right now I just wouldn't do it due to not wanting to waste the disc that's currently on the machine. The other reasons: Even when it's time to change discs, the disc can sometimes be a real bugger getting off without leaving lots of little shreds to clean off. Plus I've ruined one or two discs just by not getting them applied right. The hook and loop pad would solve those problems. I'll have to google up the Industrial Abrasives site and find that pad once my current supply of PSA discs runs out.

[Jim Becker]

Doug, hook and loop would be convenient for changing abrasives, but it would affect the accuracy of your ability to use the sander for it's intended purpose...shaping wood. H&L adds some "give" to the surface. That's good for a ROS, but not necessarily desirable for a disk (or belt/edge) sander. You want the "hardness" in that case.

[John Gregory]

Doug, hook and loop would be convenient for changing abrasives, but it would affect the accuracy of your ability to use the sander for it's intended purpose...shaping wood. H&L adds some "give" to the surface. That's good for a ROS, but not necessarily desirable for a disk (or belt/edge) sander. You want the "hardness" in that case.

I agree with Jim, Plus H&L gets damaged very quickly with heat. I found that out on my ROS :mad: . I have a 12" Delta disk sander, not sure what grit is it, my guess is 80 or 100. I only replace it when it wears out. I use those eraser type blocks to keep it clean and effective.

[Jeff Singleton]

In the patternshop I keep 36 grit on my 24" Master and it cuts very agressive, to much for furniture. On my State 20" disc I keep 80 grit and use it for furniture. I will only use glue on disc, no PSA for me. The PSA are a bear to get off most times and they cost more. I use Kindt-Collins Master disc cement, brush it on both the paper and disc, wait about 1/2 hour and postion it in place and pat it all around. In patternmaking it is not unusual to sand of 3/8" or a 1/2" of on a pattern that might be 16"-20" tall so the 36 grit does the job great were as 80 or 100 would burn up. I pay about $12.50 for 24" disc in 36 grit in aluminum oxide, forget about garnet, does not last. I get in at Lake Erie Abrasives in Cleveland and AA Abrasives in Philly. Both also have great prices for spindle sander sleeves. I think a disc sander needs a solid packing like steel so hook and loop are out. I don't think you could sand a straight edge and besides if that baby ever came off it would be like a glass Fresbie and would probably do a number on the edge of your table.

Jeff Singleton:)
Singleton's Woodworking & Pattern Works