Okay, I've got a finishing question..............

Mark Rios

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Central CA
Okay, you have a board. Let's say a hardwood board since that's what we mostly use around here. You sand it initially, with let's say....100 grit, to get it generally smooth and round off the edges and so forth.

Is there a difference in finish material penetration, i.e. BLO, stain, gel stain, clear lacquer, clear poly, etc., between the sanded surface at 100 grit and continuing to finish down to 220? down to 400? 800? 1000? I realize the some finishes are meant to stay on the top of the surface and not actually penetrate so I'm asking genrally here:
Does the porosity of the wood change as you sand to a finer/smoother surface (before applying any finishing product)?

I seem to remember being told a long time ago that one can help keep end grain from absorbing too much finish material (and subsequently getting too dark) by sanding to the next higher grit or two. Does this sound right and does it apply to the above question?

Thanks for your insight, explanations and info.
 
To my limited understanding, yes, sanding to a higher grit/smoother surface will result in less absorption. The smoother surface will have fewer variations in the surface to absorb stain or oil in a given amount of time.

Now for the professional answer.... tod??? :D :D
 
To my limited understanding, yes, sanding to a higher grit/smoother surface will result in less absorption. The smoother surface will have fewer variations in the surface to absorb stain or oil in a given amount of time.

Now for the professional answer.... tod??? :D :D
My similarly limited experience confirms that rougher surfaces absorb more finish, too.
 
yup, picture the scratch pattern left by the abrasive, big honken rocks leave big honken scratches for the pigments to lodge in.....if a fellow is using dye instead of stain the differance isn`t quite so noticable but it is still noticable.

for what it`s worth, it`s very seldom that i sand anything that`s to be stained past 150-180 on a random orbit sander just cause the scratch pattern is minimal and the pigment retention is good......tod
 
Sanding

I think even those weirdos who like sanding stop at 220 on bare wood. I'll sand with an ROS to 150 and then hand sand with the grain to 220. Even better, a nice pass with a sharp plane or scraper can save you most of that sanding. I did a test last winter on several scrap pieces. I stopped at 80, 120, 150, 180, and 220 on different pieces. Then thin shellac, blo, and varnish. Couldn't tell the diff after 150. This was on mahogany - YMMV;)
 
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