Hammered Dulcimer design, construction, and unrelated stuff

Sunday, October 18, 2015

On How to Properly Sand, and do a Hand Rubbed Finish

I really like Minwax Wipe On Poly.  I have been using it for years now as a sealer under shellac, but have recently discovered how to do a really nice hand rubbed finish with it.

The secret is in the sanding.  The finer the grit the surface is sanded to, the less poly it will absorb, and the quicker a gloss will develop.  So I currently sand starting at 100#, then 150# over the whole dulcimer.  The edges are sanded on a big edge sander, and the top and back are sanded with a stroke sander.  After that, I sand 150# with an air powered  random orbit sander followed by 180# on a different sander, and 220# on a third.  By this time the surface is feeling silky smooth.  Then I go over the whole dulcimer lengthwise to the grain by hand with 400# on a sanding block.

Then blow off the dust followed by wiping down with a tack cloth, then apply the first coat of Wipe On Poly as thinly as possible, but making sure the whole surface is covered.  I don't wipe off the excess, just make sure there isn't so much on as to drip or drool, then hang the dulcimer up to dry in the clean room.  After a couple hours the poly is cured enough to scuff sand with 220#, just enough to remove any dust motes, and make the surface smooth again, then blow off and wipe down with the tack cloth again.  The sparingly apply a second coat of Wipe On Poly and hang up to dry.

Next day I go over the whole surface very lightly with a worn out piece of 400# paper, just enough to get off any dust motes.  Then wax, and the finish is silky smooth!  I've been using the satin Poly, and it has a beautiful glow done this way.  I think if I wanted a higher gloss, after the 400#, finish sanding the wood with a quick once over with 600#, and in between coats of poly, scuff with 400# instead of the 220#.  The gloss Poly would also help.