Checking for proper finish sanding

[Jerry Bruette]

I'm working on a gun stock and think I have it finish sanded to 220. If I wipe it down with some MS will it show if I did a good enough job sanding e.g. no swirls, no coarse lines, no cross grain etc?

Will the MS just evaporate and not interfere with the final finish?

[Paul F Franklin]

That works for me. I try to look at the piece from various angles with respect to the light in order to best see any scratches. You can also use denatured alcohol; it evaporates faster.

[Mark Bolton]

MS, DNA, or water is what we use. We dont go super fine as a rule so i dont know how fine will show up but MS wa saleays the default. Water serves double duty as a grain raise.

[Kevin Jenness]

Wetting out the wood with solvent can help show flaws, especially swirls and glue spots and other contamination that will inhibit finish bonding, but good raking light is essential. Mineral spirits will take longer than many other solvents to evaporate. I would be cautious about using it before waterborne finishes.

[Jim Becker]

You "can" use mineral spirits, but I've switched to naphtha or alcohol because mineral spirits sometimes has just enough residue that it "could" affect the waterborne finishes I tend to use. Water, as Mark mentions, is also just fine, especially if you intend to do a grain raise and a final fine sanding to knock off the fuzz once it dries. Distilled water is best, but honestly...I just use tap.

[Jerry Bruette]

Don't think I'm interested i raising the grain, so if I use alcohol should it be DNA or is rubbing alcohol good enough?

[Paul F Franklin]

Rubbing alcohol is isopropyl alcohol diluted with about 30% water. It will work to show sanding defects, glue, etc, but will tend to raise the grain where DA usually doesn't. And because of the water, it is slower to dry than DA.

[Mel Fulks]

For years I didn’t know what “raising the grain” was. When as an employee, I had to do it ,and learned it got rid of “whiskers” ,I remembered
the specks of debris in my amateur efforts. 150 grit was local standard, occasionally 220.

[roger wiegand]

Raising the grain at the last sanding step and quickly taking off the raised fuzzies with a fresh, sharp piece of sandpaper of the final grit is well worthwhile. I think you will find it improves your finishing outcome. So I'm in the camp that would use water for the check you suggest.

[Scott Holmes]

When I'm using a finish that raises the grain... most do a t least a bit...

Even after coloring; sometimes the colorant raises the grain.
I give it a finish coat or two.
THEN, I lightly scuff sand with 220 or 320 open-coat sandpaper.

The clear finish locks the little wood whisker and the sandpaper easily takes them off. This method is my choice because wetting the wood, then sanding reduces the raised grain; however it does expose fresh fibers that will raise up with the next coat of color or finish. it. This method does not expose fresh grain to raise up on the subsequent coats.