It’s a Continuous Process
In the first post in this series I suggested that finishing starts at the beginning of the project. I’ll expand on that concept in this post, suggesting that finishing is really a continuous process that extends throughout design and construction.
In a very real sense, one of the first considerations a woodworker gives to a project is the finish. You’ll ask yourself questions early on in the project like “Where will this piece eventually live?” “Am I trying to match the appearance of existing furniture or have the piece make a bold statement of its own?” “Am I going to paint this piece, or let the color and graphics of the wood make their own contribution to the overall effect?”
The answers to these questions will, to a large degree, drive your stock selection. If you plan to paint the wood, you might select birch, or poplar, or some other “paint-grade” stock. If you are trying to match an existing decor, you most likely will look for stock of the same (or similar) species. If you want the piece to make a bold statement in a room full of cherry or walnut, you might prefer the contrast maple would offer. In the first case, you will probably obscure the figure of the wood with your paint. In the latter two examples you will most likely want that figure to be seen and admired. In all cases, though, how you treat the wood during the rest of the design and construction process will either complicate your life or make it somewhat less stressful. So your consideration of the finish really should begin at the beginning.
Save your Off-Cuts
I will mention here some excellent advice I received a long time ago, and which I have repeated often on various blogs and in classes. No matter what finish you plan to use, save pieces of the project stock for later use as finishing samples. This advice is particularly true for stock that makes up what I will refer to as the “show surface”. Generally, “show surface” means the part of the furniture that will get the most attention, either visually or tacitly. In a table, the show surface would logically be the top. For a chest of drawers, you would be concerned with the top, and perhaps also the drawer fronts or one of the sides of the chest. What a piece of furniture looks like is half the battle. What it feels like is the other half, and unless your creations go directly from the shop to the Smithsonian, people will touch what you make. I’ll discuss this concept more in a later post. For now, just remember to save pieces of this stock. Pieces six to eight inches wide and eighteen to twenty-four inches in length are ideal. Again, more about this in a later post.
Care During Assembly
You’ll find a ton of advice in woodworking magazines about careful techniques. There are two or three that I want to repeat, and at least one that I haven’t read elsewhere, but that I observe in my own shop.
Control Glue Squeeze-Out
Glue is your friend, right? Well, sure, it helps to hold a joint together, but that’s as far as it goes. Either it dries too quickly (always during a glue-up) or not at all (when you want to move ahead with the project). Glue is NOT a friend to the finisher. So you must learn to control it.
I’m not going to repeat all of the tips and tricks that have been written about elsewhere telling you how and where to apply glue in a joint. What I will say is that you need to keep the glue IN the joint, and OFF the surfaces of wood that will be finished. However, no matter how careful you are, some glue is going to get where you don’t want it.
Glue gets to the outside of a project in a couple ways. It either squeezes out from a joint, it drips from somewhere else, or we spread it around with our hands.
Gravity can help or hurt
When you glue up a panel – a table top or something similar – set the glue-up off to the side with the glue seam perpendicular to the floor. That way all the squeeze-out will stay localized to the joint. The squeeze-out will run down the joint toward the floor. Placing the glue joint parallel to the floor invites the squeeze-out to run down both faces of the panel as gravity does its job. Use this same technique to your advantage when you glue up other joints. The idea is to keep the glue localized, and prevent its movement on the exterior surfaces of the project.
Getting Rid of Squeeze-Out
When glue squeezes out, my advice is to just leave it alone. I don’t agree with the technique that a damp rag will take care of wet glue. Glue and water are sometimes mixed together to create what is known as “glue sizing” which is frequently used as a stain controller. In other words, it slows down or stops the penetration of finish into the surface of the wood. Why create that situation unintentionally? Instead, set the glue-up aside, and monitor the glue as it dries. Wait until it gets to a rubbery condition, and then use a putty knife or a paint scraper to remove it. Don’t be tempted to do this too quickly; glue skins over fairly rapidly, and what might look like solid rubbery balls of glue can conceal liquid glue in their cores. If you start scraping too soon you’ll just break open these little glue bottles which will then spew their contents all over your project. Let them dry, but don’t let them harden. You’ll be pleasantly surprised at how easy it can be to remove glue in this condition. Letting glue dry overnight just makes your job more difficult.
Keep Your Hands Clean
When furniture maker Phil Lowe glues up a table top, he uses a Mark-I glue spreader. Before you run off to Google, I should explain that a Mark-I glue spreader is more commonly referred to as a right index finger. The Mark-I has a number of advantages. Primary among these is availability, presuming you have managed to keep it attached to your hand. The Mark-I is also quite effective. These qualities should encourage you to use push sticks.
There is a drawback, though. Glue on the fingers ends up being glue on the project, unless you are really careful. If I’m using my own Mark-I, I keep a wet towel on my work table, and I carefully wipe glue from my hands before touching the work. A second option is to use a small scrap of wood as a glue spreader. This technique might be a little slower than the Mark-I, but you pick up the time not having to clean your hands. I decide which technique to use based on how complicated the glue-up is. If it is a panel, the Mark-I is my first choice. If it’s dovetails or mortise-and-tenon, I use a stick, an accordion bottle, or some other precise way of getting the glue only where I want it.
With practice, you’ll figure out how much glue is the right amount. You do want to see a bit of glue coming out of a panel glue-up, but you don’t want to see anything outside the mortise-and-tenon joint. In the final analysis, controlling glue is a matter of experience gained through practice. From the perspective of the finisher, the less glue on the show surfaces, the better – but what does squeeze out must all be removed before you start applying a finish.
In the next post I’ll get into the subject of hand- vs. power tools, and how those decisions and techniques affect your finish, and continue with the discussion of care during assembly.
Jeff Zens owns and operates Custom Built Furniture in Salem, Oregon. He is a frequent woodworking instructor and writer.