monty1975

Stupid question time... I'm sanding shellac with 3M brand 220 grit sandpaper and the sandpaper is clogging rapidly. After about 50 strokes the shellac is piling up on the paper like this:



There are no visible high spots on the face of the block, i'm using light slow strokes, and the shellac has dried for 24 hours in a dry space and feels nice and hard.

Tried with 150 and 100 grit and it was worse. Tried with 320 and it was a little better. Am I doing something wrong or should I plan on changing the paper 10 times every 20 square feet?

Thanks,
brian

Rick Mosher

Garnet isn't the best choice for sanding finish. It also looks like the finish may not be completely dry. Get some 3M fre cut white silicone carbide sandpaper #415N.(I prefer 320 grit for sanding finish) You won't have the problems with clogging as long as you let the finish dry completely. (Is that shellac fresh? Sometimes canned shellac will go bad and not dry properly)

monty1975

Rick,
Thanks for the quick reply. The garnet shellac was homemade and as fresh as it gets- about 24 hours old. I put down four coats of about a 1.5 lb cut.

Interesting - Do different shellac colors sand differently? I have super blonde flakes, amber, garnet, and ruby. Does it have something to do with dark/light? I was planning on laying down a few more light coats of garnet after this initial sanding, doing a super light sanding, and then laying down a single coat of super blonde. I'm really trying to darken the wood up as my stain didn't go as dark as I had hoped.

I did notice that the super blonde really flows off the brush differently than the garnet....

How long does Shellac take to completely dry when using a 1.5 lb cut?

Shellac is cool stuff but i'm still on the steep part of that learning curve.

again - thanks
Brian

Rick Mosher

Sorry, the garnet I was referring to was the type of sandpaper you are using. Silicone carbide lasts much longer and doesn't clog easily.

cabinetman

The shellac may not have cured completely. You could try the Norton brand (made in Canada) A413, 320x (marked 320A), called No-Fil Durite. It's a light gray silicone carbide (intended for dry use). You could also try the dark gray to charcoal colored wet-or-dry silicone carbide paper (works best when wet) (320x), with water.

ACP

There is a shelf life on clear shellac flakes too. Not just in liquid form. I don't know if that is an issue. I would let it cure more. Like the others said, silicon carbide. Stearated for dry and non-stearated for wet.