The Perfect Wood Panel Glue Up

There are times when you will not be able to buy wood wide enough for your project (or it would be prohibitively expensive) and it's not reasonable to use plywood. In this case you will need to glue up a panel from a series of smaller boards. In this post, I will describe the process for creating a wide panel that is flat and straight.

Wood Selection

The process of building a wood panel starts at the lumberyard. The wood you select not only determines how the panel will look, but how the wood responds to changes in moisture.

All things being equal, quartersawn lumber is less likely to cup and warp than other cuts. However, these days you're not likely to find wide boards that are all quartersawn. So pick boards that are not already warped or cupped. If the wood is pretty straight to begin with, it's likely to stay that way as you mill it.

In addition, pay particular attention to the color and grain of the wood you are selecting. Unless there's a particular effect you're going for, try to pick boards that are of similar color and grain. Doing so will make it easier to make the boards appear as though it's one, seamless panel. The best way to achieve this is to try and find a single board that you can cut into sections and glue together to make the panel.

Stock Preparation

As in every other aspect of woodworking, how you prepare your wood will affect every subsequent stage of the project. If your boards are not flat, straight and square, you'll find it difficult to get them assembled into a flat panel.

After you've selected your boards and cut them to rough length, face joint, thickness, edge joint and rip to width each of the boards as I as I describe in my post on stock preparation

Arrangement

Once you've selected your boards and cut them to rough length, lay them out on your workbench and deterimine which edges to match up. One rule of thumb suggests that you make sure the growth rings alternate (that is, one board curves up, the next curves down, etc.). Another says that the grain should all go the same way. While these ideas have merit, the most important thing to consider is the look of the finished panel. So if you can get the grain of all the panels to line up in the same direction, great, but not at the expense of the appearance of the panel.

If you bought your lumber in the rough, you will have to face joint and thickness the boards before you can really get a sense of the grain and how to arrange them

Once you have an arrangement you like, draw a big "V" across the joints of the panel or number them so that you can keep track of what order they go in

Edge Jointing

When you place the edges of the boards together, there should be no gap between them. If there is, go back to the jointer and make another pass or two to get the edge perfectly straight.

If you're using hand planes, takes the two boards to join together and fold them together like a book. Then, use your jointer plane to true both edges at the same time. By planing both boards at the same time, any variation in the edge from 90 degress will cancel out.

Some woodworkers like to join panel boards with a "sprung" joint. In this instance, the edges of the board to join are just slightly concave. The idea is that this keeps the ends of the joint tight. To do this, take a couple of swipes with your hand plane in the middle of the board's edge.

The Glue Up

Now that the boards to make up your panel are flat, consistent thickness and fit together without gaps, you're ready to glue the panel together. There are several ways to do this, depending on what clamps you have on hand. In every case, however, you need a flat surface to work on. If your work surfaces is twisted, there's a chance that twist could translate into your panel as well.

Lay out your choice of clamps and place your boards across the clamps and make sure you have everything you need before applying any glue. Squeeze some glue on to both edges of the joint and spread it out to a thin layer. There are glue bottles with a roller made for this application, but I find that just using a small piece of scrap wood works just as well for me. You want to cover the edge completely, but try not to apply too much glue, as it will just squeeze out when you clamp the boards and make a mess.

Push the boards on the clamps and push the edges together. I like to slide the joint back and forth a bit to help spread the glue and create a bit of suction to hold the boards together while adjusting the clamps.

The remainder of the glue up depends on what kind of clamps you have:

Parallel Clamps. If you have several parallel clamps, such as the Bessey K-Body or Jorgensen Clamp Master, the panel glue up is pretty simple. Push the boards down against the bar of the clamp and then tighten up the clamp, making sure the boards stay against the bar as you do so.

Pipe Clamps. Pipe clamps have a few problems that you need to account for during panel glue ups: The jaws are not parallel, the jaws can mark the wood and the bar tends to deflect as you tighten the clamps. The latter is especially true if you're using 1/2 inch pipe instead of 3/4 inch pipe.

To handle the non-parallel jaws, cut some pieces of dowel with a diameter about the same as the thickness of your panel. Place the dowel between the clamp jaw and the edge of the board. This makes sure that the force of the clamp is centered on the edge of the board. In addition, it keeps the clamp jaw from mar the wood edge.

To account for the deflection of the pipe, it is often useful to use some clamping cauls across the panel, perpendicular to the panel joints. To make a pair of cauls, cut some boards longer than your panel is wide. Try to make the edges slightly convex so that, when the pair is clamped together, the clamps will pull the joint flat. Apply some packing tape, painters tape or some other kind of tape to keep the glue from stickiing to your cauls.

By carefully preparing your stock and taking your time when clamping the boards together, you'll have a nice flat panel, ready to trim to width and crosscut to length for use in your project. What techniques do you use to glue up your panels? I'd love to hear any tips or ticks you might have!

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