Under what circumstances do you purposely raise the grain before finishing?

Hi all,

I recently was finishing a number of Baltic birch cabinet panels before assembly. Some of these panels were being finished with water-based polyurethane, and others were being finished with an oil stain and oil wax (Osmo polyx).

I accidentally applied polyurethane to one of the panels that was supposed to be oil stained and oil-waxed. As a result, I waited for the poly to dry and then used my ROS and 150 grit sandpaper to remove the poly.

My plan was to finish sand the piece to 220, but I was surprised when I finished with the 150 to have a panel that felt and looked noticeably smoother than I am used to with 220 grit. Since Osmo recommends sanding to lower grits if possible in order to receive the oil-wax better, I stopped at 150 and applied my stain and finish. The end result is a panel that is nicer than any other I've finished with my normal "correct" technique.

My guess is that the accidental application of the water-based polyurethane raised the grain and that then using my ROS removed the raised grain "whiskers" to leave a very smooth finish. The oil stain and oil-wax finish did not further raise the grain.

This all leaves me wondering if I should always purposely raise the grain before finishing with oil. The product instructions for my oil products do not mention this step, and the advice I've seen on Youtube (example) and elsewhere discusses raising the grain as a technique to help with water-based finishes, not oil-based.

So when should grain be raised and sanded on purpose before finishing, and when should it this be avoided?

Thanks for reading :)

By wiping with a really damp cloth and then letting it dry COMPLETELY and then finish sanding before applying any finish coat(s), either water based or oil based, I find it works much better.... just my opinion...
Also, wood species does not matter... use basically same technique on walnut, cherry, poplar, maple, etc...

Also, poplar and pine sometimes will wipe with damp cloth again after sanding and wait for it to dry again...then sand and finish..

How much grain will rise after wetting will sometimes depend on how the board is cut, i.e. flat sawn will rise more the quarter-sawn wood...

I used to raise the grain on my furniture with a cloth dampened with water, let it dry and did my final sanding. I did this a lot with cherry that I sanded with a sanding block and garnet paper. When I look at my old stuff, I see a lot less blotchyness than I see on my newer cherry stuff that I sand with a ROS and no grain raising.

Having not done side by side comparisons I couldn't say for sure, but my feeling is raising the grain will reduce blotchyness. Curious what others think.

I can't think of a time when I haven't done a wipe with a damp cloth prior to the final sander pass. It leaves a much nicer surface with no issues downstream. Why would you ever leave this step out?

I don't raise the grain if I am putting on shellac as a first step or a second step after using an oil based stain/Watco. Since I need to sand to denib the shellac anyways, the small amount of raised grain gets taken care of at the same time. If I am putting on anything waterbed as a first step I will raise the grain prior.

Some reading this might not even understand “raising the grain”. I was reading about woodworking as a kid and never saw a good explanation. Sanding tears fibers up...and then smushes them down. So when you put on a finish it makes the fibers vertical and ridged.....
like some medicines for men. Lots of varnish or lacquer can make the “stumps”look like spilt pepper on the finished finish....like a face
just before it’s shaved. Raising the grain needs to be changed to “popping up the fibers,to make them easy to cut off with a piece of
new unused sand paper”...Soooo much easier than sharpening old sandpaper. This is the best explanation I’ve ever seen ! But I’m not gonna
copyright it ! Feel free to use it unattributed. I’ ve always believed in “giving something back to the science” !

Mel: as a relatively new woodworker (can I call myself that yet?), I completely agree that "raising the grain" is usually referred to without any further explanation. I wonder how many people read the phrase and think they know what it means, when in reality they just know how to solve the problem. I only learned that "raising the grain" really means "popping up the fibers to make them easy to cut off before final finish" from doing some more in-depth reading after my recent experience that I wrote about in the OP.

In any case, yesterday and today I've been finishing a few additional door panels with an oil stain and oil finish. This was the first time I've purposely raised the grain before applying the oil stain, and I'm happy to report that it had its intended effect. I have a silky-smooth finish with just one coat of Osmo Polyx.

Thanks, Ken. And I just now remembered the old term, it was “sponging”. It’s possible that went out of use when some who were new to
wood working didn’t understand the term and thought...”nahh,gonna BUY my wood !

Quote:

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Originally Posted by Andrew Seemann

I don't raise the grain if I am putting on shellac as a first step or a second step after using an oil based stain/Watco. Since I need to sand to denib the shellac anyways, the small amount of raised grain gets taken care of at the same time. If I am putting on anything waterbed as a first step I will raise the grain prior.

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I did the shellac as a first coat trick on some softwood panels. Spray Sealcoat, sand (quick and easy) then water based enamel. Really smooth, it looks like I knew what I was doing. Of course I did this in the summer so now there's a bit of bare wood peaking out around the edges. Can't win 'em all.