Sawdust on the Floor

I had a friend ask what was involved in turning rough lumber into something that can be used to make furniture. The reason for his question, he had heard of a great deal on some rough oak, with a price that sounded really good. The only problem, his collection of woodworking tools is somewhat limited to a good tablesaw and some other hand tools.  Add to this the fact that some place he had heard that you could actually dress lumber on a tablesaw, so he asked is it true?

I hated to burst his bubble, but the table saw is one of the last tools to be used when you are dressing lumber. For clarification, some lumber yards sell lumber labeled as “rough” that has the top and bottom surfaces sanded smooth leaving only the two edges rough. This lumber can be cleaned up with a sharp table saw blade, and some hand sanding. All other rough lumber needs to have all four sides treated or dressed before you can use it.

But before we begin working the wood, there is one additional step that you should undertake. Unless the lumber stock is from your own trees, and you are 100% certain that it never had a nail or screw driven into it. then you need to check the stock for hidden metal. One small nail or screw that the tree has grown around can and will cause serious damage to your woodworking tools. I use a small metal detector similar to the ones the TSA people use at the airports, to check all rough stock before I ever start working on it.

Once you are satisfied that the stock is clear of any metal, clean off the wood with a good stiff brush to remove any dirt that may still be on the wood. The dirt and debris that is often found on rough lumber can cause as much damage as the metal particles if left on the surface of the wood. Take the time to clean it before you start working on it.

The first tool that is needed to dress the stock is the jointer. We start by running one edge of our stock over the knives of the jointer, repeating this action until you have created one straight smooth and continuous edge. At this point, the stock will lay completely flat along the entire length of the infeed and outfeed tables of the jointer. The next step is to rotate your stock 90°, from your first edge. This will allow you to work on the adjacent edge of the stock. Just like the first edge, move this edge over the knives repeatedly, until you have a straight, flat edge. While you are working on the second edge, be sure that you hold the first securely against the fence of the jointer. This ensures a 90° angle between the first and second edge.

My jointer has a 6″ wide bed, so that is the widest board that I can accommodate on my jointer. Any stock that is wider then this 6″ limit, will be ripped down to 6″ width. After the stock is dressed, If a wider piece is needed I will glue it back together. Getting the stock dressed correctly is too important to skip these steps just because you want wider stock.

With all of your stock dressed with two edges, now its time to take your stock and run it though your surface planer to dress the remaining two sides. Start by placing one of the dressed edges on the bed of the surface planer, plane the opposing surface to your desired thickness. Once this surface is at the desired thickness we can move on to the fourth side. Rotate the stock so that the other edge you dressed on the jointer is now on the bed of the plainer and plane the opposing surface for its final thickness. It’s very important in these steps that you always work off of the surface that you dressed on the jointer. Keep that surface against the bed of the planer. Don’t flip the stock over as you plane it, work on one surface only. And here is the reason why.

Turn the power off on your planer, and look inside. You will see two rubber rollers, one on the infeed and another on the outfeed side of the planer knives. Under ideal conditions these rollers will hold your stock evenly against the bedplate of the planer. For that to happen the surface of the wood against the bedplate must already be flat. Under this condition the roller hold down pressure will remain constant over the entire length of the stock. When this happens the top surface of the stock is planed parallel to the bottom surface. And since we started with a bottom that was already flat from the jointer the two surfaces end up totally flat and parallel to each other. Planers work to make the top surface, parallel to the bottom surface.

Back to your stock, you have one surface already dressed on the jointer while the other is still rough. If you were to run the stock through the surface planer with the rough edge down, this rough edge now becomes the reference for the top edge. The planer will start working to making the top surface match the contour of the bottom surface. If the bottom is bowed or cupped, that is what the planer will try to duplicate on the top surface. So keep the good side down always.

Remember that most woods actually have some physical memory. The rollers may force the stock down while it is under the roller pressure, but the wood will return to its original shape once it is free from the force of the rollers. In other words, a bowed piece of stock will still be bowed after you take it though a surface planer, it just will be a thinner bowed board.

When we started off running the stock over the jointer, there were no rollers on the jointer to affect the shape of the wood. You simply keep passing the stock over a single knife point until, the edge of stock could lay totally flat against both the infeed and outfeed tables of the jointer. That edge is then used as the reference side in the planer.

Getting back to my friend, he has neither a jointer or surface planer. I suppose he could get by purchasing the more expensive partially dressed stock, or he could invest in a good jointer and surface planer. I suppose there is a third option, he could find a friend who already has the tools and work out a trade for some of the rough stock, for some shop time. I wonder what kind of a deal we can work out?

Related posts:

1. Reclaimed Lumber
2. What Tools Should Be Included in a Complete Woodworking Shop?