How to Plane the First Face of a Board Flat
I almost always start a project by figuring out where each of the individual parts is going to come from rather than just cutting up a board at random. There are a few reasons for this. First, I want to make sure that each part will have the best visual and structural grain orientation and pattern before I start to cut anything up. For example, I want the straightest grain possible for parts like table legs, frame rails and stiles, and drawer blades. For things like door panels and drawer fronts, I want the best looking grain. This might be a wide cathedral grain for a door panel, or a sequential grain for adjacent drawer fronts.
Second, I want to make the most efficient use of the lumber that I have. Sometimes the grain in the boards that I have works out so that I have almost no waste, but this rarely happens. There’s almost always some waste because getting the grain right is more important to me than minimizing waste.
Third, I want to plan my crosscuts and rip cuts to minimize the impact of warping in the board as much as possible. By cutting boards into oversized project parts before I start planing, much of the cup, bow and twist can be managed with the saw rather than the plane. I talked about how to do this last time.
Once the planning is done and the parts are cut slightly oversized, only then do I pick up a hand plane. The plane I start with is the fore plane or jack plane (two different names for the same plane). This plane has an iron that is sharpened with a moderate camber. In other words, the edge of the iron is ground in an arc across its width, not straight across. Cambering the iron helps to ease planing and keeps the corners of the iron from leaving tracks in the surface of the board. The plane is set to take a relatively thick shaving, however, it shouldn’t be so thick that the plane becomes difficult to push.
I prefer to work the convex face of the board first as it will typically be more stable if the concave face is placed down on the bench. I begin the process by planing directly across the face of the board, but only along the center of the board’s width. My goal is to reduce the crown at the center of the board. Eventually, the plane will not cut just in the center, so I will plane a wider path, further reducing the crown. By occasionally checking with a straight edge, both across the width and along the length of the board, I can locate the remaining high spots and only plane where necessary to bring them down. This reduces the amount of work and preserves as much of the board’s thickness as possible.
I’ll know that I’m done with the fore plane when I’m taking full length shavings across the board and my straight edge shows the board face to be in a general state of flatness, both across the board’s width, and along its length. At this point the face of the board will not be completely flat. The surface will be scalloped from the curved blade of the fore plane, but this is as far as the fore plane can take the board. So, either the job is done (perhaps if the surface is the bottom face of a table top), or I move on to a finer tool.
If the surface requires greater refinement, such as the top surface of a table top, a case side, drawer parts, etc., I switch to the try plane. The try plane has a cambered iron like the fore plane, but the camber on the try plane iron is substantially less than that of the fore plane iron. In fact, the camber is so subtle that it may go unnoticed, until a straight edge is held up to the edge of the blade. This very subtle camber allows the try plane to further flatten and refine the surface, but still prevents the corners of the iron from leaving tracks.
I use the try plane to work diagonally and along the grain. Because of its length, the plane will only cut the high spots until they are brought down level with the low spots. Therefore, the length of the plane is an aid in making the board flatter. I again occasionally check with a straight edge, both across the board’s width and along its length, and I stop planing when the straight edge tells me that the face of the board is flat.
I’m very careful here to pay particular attention to the center of the board to make sure that it isn’t bowed along its length. If it is, the plane may cut a full length shaving from end to end, but it will follow the bow. If the board is bowed, I’ll plane just the center of the board’s length to bring the bow down and continue in this way until the face is flat from end to end.
At this point I will also check the face of the board for twist using a pair of winding sticks. Following the process of planing across the board with the fore plane and then diagonally and along the grain with the try plane typically removes minor twist in the face of the board. However, it’s necessary to make sure that all twist is removed before squaring an edge to the face or planing the board to final thickness, otherwise the twist will end up on both faces and the edge as well.
To use the winding sticks, position them at opposite ends of the board and sight across their tops. If the face of the board has any twist, it will be obvious because the tops of the sticks will not be parallel to each other. If the face of the board is flat, the tops of the sticks will line up parallel. If there is any twist in the face of the board, plane diagonally across the high corners to remove it. I typically check the board with winding sticks at the ends, and then alternately with one of the sticks in the center of the board, just to be sure.
Once the face of the board is flat, I don’t plane it any further unless it’s a final show surface for something like a table top, which will receive a lot more scrutiny. In these cases, I’ll make a few passes with a finely set smoothing plane during preparations for applying finish. In most cases, however, the surface left by the try plane is acceptable as is and requires no further work.
At this point, I can move on to the next step in the process. However, the next step in the process will vary depending upon what the board is going to be used for. If the board will be glued up into a wide panel, then it’s ready for match planing with another board. If it will be a drawer front, or other similar part that needs to be dressed on all four sides, then the edges can be addressed next.
If the second face of the board needs to be planed flat and to a specific thickness, I will wait to do that until I have addressed the edges, if I am doing the job with hand planes. It’s slightly easier to hand plane a board to final thickness if the edges have been planed first. If I’m using a thickness planer, I’ll send all of the boards through the machine after hand planing their first faces flat. The thickness planer doesn’t care if the edges aren’t yet planed.
However, as this series is intended to explain the process of milling lumber with hand planes, I’ll address the edges next.