Fine Furniture Finishing Newsletter, Issue 3

This issue's topic: Wood stains and staining.

"The end-grain gets so much darker than the rest of the wood, no matter how

little I try to put on. What should I do?"

"When I was trying to stain some poplar, it came out blotchy. How should I

fix it?"

The answer to the first question is easy enough; the second question is

tougher. End grain on wood is just like the end of the stem of a cut flower.

Just as the flower stem sucks up the water in the vase, so too did the wood

use to do for the tree. Now that it's a board on your project, it is ready to drink

up whatever you brush on it, whether it's stain, paint, or varnish.

When you're painting raw wood, oftentimes you'll notice that any end grain

pulls in the primer coat. Usually you just dab on a little more primer on those

areas and you're all set. When you topcoat with your color coat, it all sits on

top of the primer quite nicely. The same is true for clear varnishes; the first

coat or two is pulled into the end grain, making those parts appear duller or

rougher than the rest. Usually by the second coat, -and certainly by the third

coat, everything has evened out and looks fine.

The problem comes with stains because they are neither opaque like the

paint, nor clear like the varnish, but are translucent. So, the more stain you

apply and let absorb into the wood, the darker it gets. Since end grain always

absorbs more of anything than the other parts of the wood, it ends up darker.

After that long preamble, the answer may already be coming to you; let your

wood absorb something clear before you give it a chance to absorb something

with color in it.

There are three generally accepted ways to do that. One method is to flood

the end grain with the type of solvent that your stain uses so that it's already

"filled up" by the time you apply the stain. Not as much stain can be absorbed

since the wood cells are already full of solvent. The solvent would be water with

water-based stains, mineral spirits with oil-based products, or alcohol for those

who are using alcohol-diluted aniline dyes.

The advantages to this method are that it is fast, and if you slop a little

solvent onto the adjoining face grain, there will be little problem avoiding light

colored areas on the face grain. The disadvantages are that once you flood

the end grain, you have to get the piece stained and wiped before the solvent

is totally absorbed or evaporates, so you have to work quickly. The other

problem is that it's near impossible to judge how evenly you got your piece

colored; the flooded end grain will appear very dark while wet, but may dry a

whole lot lighter than the surrounding wood if it didn't get enough stain.

The second way to solve the problem is to give it a light coat of varnish first.

The varnish will be partially absorbed into the end grain cells and limit how

much colored stain can be absorbed, keeping it lighter.

The varnish solves the haste problem of just using solvent, but introduces two

new ones. One, you have to wait for it to dry before you can move on to the

staining. Don't rush it or you'll end up with sticky goo! The other potential

trouble happens if you get some of the varnish onto the face grain without

wiping it off while it's wet. Later, when you start staining, you'll discover that

not only did the varnish work on the end grain by preventing too much stain

from coloring the wood, but it's equally effective at preventing the stain from

coloring the face grain, -leaving you with a much lighter part of a board that is

difficult to fix by trying to blend.

The third solution, and the one I like best, is to partially seal the end grain

with white (clear) shellac. Unlike the varnish, the shellac will dry quickly, so

you can move on with the staining. The shellac is always re-solvable, so if

you accidentally get some on the face grain, you can wipe it off with alcohol

and immediately continue with the staining.

One last bit of advice on this subject; don't go too heavy with whichever of the

three methods you choose. You still want the end grain to absorb some stain

just like the rest of the project. If you use too much solvent/varnish/shellac,

you could end up with end grain that is too light. (Though that is usually

easier to cure with another coat than when it is too dark.) A little experience

helps here, and the easiest way to get it is to practice on a scrap of the same

wood. After all, you'll almost surely be trying out the wood stain on a scrap

anyhow.

The second question about getting blotchy results on poplar (it also can

happen on many other species) is not as easily dealt with. The first thing

to check for is to see if the blotching is in a pattern of jointer or surfacer

knife marks. If it is, the wood just needs to be sanded more thoroughly to get

rid of these "compressions" in the wood.

Assuming that the answer wasn't that fast, here are some other options:

You can use a wash coat of the solvent over the whole piece, just like the end

grain example above. This will be even out the amount of stain that is

absorbed in different parts of the board(s).

The shellac treatment also works, but dilute the shellac with an equal part of

alcohol or more to make a thinner wash.

There are commercial versions of both of the above that you can buy, if you want

to try them.

You can also try using a gel stain, which, being thicker (lots!) sits more on the

surface of the wood, providing a more even look. It won't get as dark, though, if

that's what you were looking for.

And finally, you can glaze the wood instead of staining it. What's the difference?

Glazing is coloring the wood after it has been sealed, instead of before. Seal the

project with your choice of varnish or shellac and let it dry. Mix up some stain (it

needs to be a pigmented stain, not a dye) with some of the same glazing formula

that we use for antiquing and faux finishing. Apply it with a brush and remove it with

a rag or towel to get an even coloring. This works great for light to medium coloring,

but may start to get a little "chunky" if it has to be applied too thickly to get a very

dark result.

Incidentally, you can get a wide range of looks by combining staining and glazing,

particularly if you like a slightly "antique" look to your wood by having the color be a

little darker in recesses or the corners. Stain the piece, and after the first seal coat of

shellac or varnish has dried, brush on a glaze coat, wiping it for the effect you want.

When it's dry, continue with your normal progression of finish coats. You can get

some really sweet and subtle effects this way.

---

In the last newsletter, I was talking about mixing colors, and had mentioned

something about matching colors. Though that discussion wasn't about trying to

match any particular color, there may be times when you wish to get an exact

match. Reader Mary Mansell reminded me, (and I'm reminding you) to always

compare dry samples when your trying to get a match. A small hair dryer is the

thing to use.

---

My featured product of Issue Three:gloves. Keep your hands handsome

(or pretty) with gloves when you're working with messy phases of your projects.

Dishwashing gloves work fine for things like cleaning/scouring old pieces in

preparation for more fun things to come. They're not made for handling paint

stripper, however, get a pair of chemically resistant gloves for that. They're

usually available at paint or hardware stores. Both of the above are usually a

little clunky for more delicate aspects where you need a better sense of touch

(blending a glaze might be an example).

If you will only be working with water-based products you can use thin latex

gloves, available at most paint or grocery stores. They melt more or less

immediately with mineral spirit-ed products though; for these I use vinyl instead

of latex gloves. They will still soften with exposure to massive quantities of

spirits, and your fingers will eventually poke through. They can be a little harder

to find, I always buy a box of 100 at a pharmacy.

---

Please forward this newsletter to interested friends.

Best wishes,

David Sorg