Yep, the first coat lightly raises the grain and freezes the raised fibers in place. Sanding then gives a smooth surface to start the final finish coats.

Keep in mind though, waterborne finishes don't add much charatcter to the wood. I usually do a quick coat of zinsser sealcoat (dewaxed shellac) to pop the grain a bit before starting my waterborne routine. Danish oil ( I use deft because it's cheaper than watco) will work too, but takes longer to dry.

I don't bother with pre raising the grain at all.

My waterborne of choice is crystalac super premium or polyoxide. I get them from mcfeely's who always seems to have $1 shipping. On a budget, rusteloum ultimate poly is another good one and really cheap.

 

Don't waste your time.

http://www.hardwoodlumberandmore.com/Articles/ArticleViewPage/tabid/75/ArticleId/28/Pre-Raising-The-Grain.aspx

 

Let dry at least 2 hours then sand with very fine sandpaper (220 grit) to ensure an even finish and proper adhesion of additional coats. Do not use steel wool. Remove all dust.

Will 320 grit sandpaper remove dust partials and provide scratch pattern that will allow next coat to adhere?

Some people recommend do not sand between coats of waterborne poly. Still others recommend using 320 grit, and say only use 220 grit on runs and dust nibs.

So apply light coat & try 320 grit between coats and tell us how you made out.

 

Finishing is really a matter of training. The article AlaskaGuy posted is good, you should read it. Also look at Charles Neil's videos on YouTube. It's really all about habits, most of us garage WW just have bad habits when it comes to finishing, but a little tweak in the way we do things can make all the diff.
I've never had a problem with hardwoods grain rising when wet. Blow them off real good with 80lbs of air and wipe with tack cloth and get rid of all the loose material.
I have switched to oils myself. I just think it makes a better finish than waterborne and is a bit easier but takes a lot more time. The wood just looks and feels more natural to me.

 

The only time I think it is necessary to go through the grain lifting process is with softwood, like cedar and pine if you intend to stain the wood. I use a pre color conditioner which needs to go on very wet and does lift a lot of grain. However you just wipe it with some 320 once and that is almost dusted off, 600 works too and if you're impulsive with sandpaper and just can't leave it at one swipe, then you should use that.

 

Like they said, let the first coat lock it in and go from there.

 

By request this is Baltic Birch Plywood. From a test spray on scrap I know that the grain does raise, but a quick pass with 320 fixes the problem.

I would have much preferred to spray with lacquer, but water based was requested.

 

Raising the grain happens anytime water or water-borne dyes and finishes touch the wood. Even after "pre-raising" you still get some swelling. The point of the article, and my experience as well, is that it doesn't matter since you will get a smooth surface anyway after you sand the first coat.

A correllary to this point is doing prep-work sanding on projects. People obsess with sanding the raw wood to 320 more, but that not only is unnecessary but can prevent good absorption of the first coat (stain, dye, oil, or finish).

I sand to 120 on most projects and 180 on end grain. The objective is not to smooth the wood, but rather to remove tool marks. The smoothing step comes after the first coat of finish when the wood is first "sealed." So, who cares if the grain is raised? It gets smoothed out after a little post-sealer sanding.

 

+1 on sanding after sealer is applied. As mentioned above people equate sanding to finer grits with having a smoother finish. Remember to "Finsih the finish." After all of the tool marks are sanded/planed away it is the finish that needs to be leverled and taken to whatever sheen one desires.

 

I do a lot of drawers using BB Plywood and finish with Target Coating WB finish. Never found a need to pre-raise the grain. My drawers look good and feel good.

 

BTW, I'm to the point where many of my projects, the raw wood seldom gets sanded. I use scrapers and planes more than anything now. Even panels that are flattened with the thickness sander get a once-over with a scraper.

I try to save the sandpaper for between coats of finish.