Water-base finishes have really come a long way in recent years, but one of the things they still do to your wood is they raise whiskers in it. It's just natural that when you get moisture on a pice of wood it raises the grain a little bit and you don't want that raised grain in your finished project. So, what you want to do, if you're gonna use a water-based stain, is de-whisker the wood ahead of time. Now I've got a couple of pieces here. The piece on my right is silky smooth, right off of my random orbit sander. The piece on the left, not so much, 'cause that one has already got started on the de-whiskering process I'm talking about. So here's the deal. I've got a coffee can full of water here and my foam brush. In order to de-whisker, what you want to do is put water on at about the same level that you would put finish on. So I'm looking at this water the same way I would look at the water-base polyurethane I'm gonna put on this later. Put it on in the same volume. What that's doing is soaking into the fibers, that's what's gonna cause those fibers to pop a little bit. And after an overnight time period to let that dry, then, the board is like this and quite rough across the face. The grain has raised all the way down the length of this board. So you've got to let the grain dry before you come back to the next step. Now, this is when we get to the de-whiskering part, so of course you get your trusty razor out of the bathroom for removing the whiskers... No, we actually want to do this with a piece of sandpaper. The key is light, light touch. If you over-sand this, what's gonna happen is, yes, we're gonna get the whiskers off but we're gonna take the wood down to a point where we have to de-whisker all over again. So I've got a 320-grit sandpaper in my sanding block. I want to just skim over the top of this with a very light touch, just enough to knock the whiskers off, not enough to get past 'em to where I'm back down to the original surface again. On this board, that's about all it's gonna take. This one's about done. Like I said, if you over sand, what's gonna happen is that you're simply gonna have to do this process all over again. Now, what the de-whiskering is gonna do for you, when you put your water-base on here you might still have a little bit of grain come up but it'll be no where near as dramatic. The big deal with that is that as we sand the whiskers off under a finish you don't want to get to a point where you're taking so much off you're taking the finish off. So what we gain by doing this ahead of time is a lot less sanding once we've got a coat of finish on here. So water-base finishes. It's a great idea to de-whisker the project before you actually apply your first coat of sealer.
Since I've heard George say that he uses Zinsser seal coat to keep the grain from raising, does he still recommend using water to raise the grain? Thanks.
I was taught to use distilled water when dying and/or raising the grain on my projects in order to keep minerals in the water from unintentionally staining the project. While most tap water might be safe to use, it may be a consideration for woodworkers in some parts of the country.
Great tip, I always wondered how you go about it. The light touch with super fine sand paper, good tip.
For an amateur woodworker who works almost exclusively with water-based finishes, this is an excellent tip - so simple. Why didn't I think of that.
thanks!