Sharpening and Using Molding Planes
As the largest specialist dealers in complex molding planes in the world, we are constantly fielding questions about the use and care of molding planes. While I am not proposing that all of these questions can be answered in this one treatise, I do hope that quite a few common questions can be addressed and woodworkers new to using molding planes might find much that is useful in these words. For those that are contemplating the jump to molding planes, I urge you to take the plunge. No other part of woodworking has been more rewarding to me than the use and study of molding planes. There is a certain satisfaction from seeing a molding take form with each pass of a molding plane that is hard to convey to the outsider, but which is frequently discussed by users of molding planes. The means become more important than the ends.
When choosing a first molding plane, it is important to assess not only the particular plane that you buy, but also to decide on type of plane to go for. I strongly urge customer to start out with a profile that is easy to use, but highly useful in cabinetmaking. Most of our customers are of course buying these planes for cabinetmaking uses. A small cabinet ogee, 3/8” to 5/8”, or a square ovolo, ¼” to ½” are my favorite choices to begin. These are the most useful sizes and other more complex profiles, while appealing, can be much harder to set up and use, and might lead to frustration that would cause you to prematurely abandon what will be important woodworking skill.
Once you decide to try a molding plane, there are a few points of which to be aware, besides the obvious point that you don’t want a plane that has been used to death and is totally worn out. There are far more molding planes surviving in the world today, than there are useable molding planes. The very design the molding plane, with most of the wood removed at the center of the plane for the wedge mortise and the mouth, leads to planes warping at this point. Perhaps half of the planes that I handle are too badly warped to be used. American planes tend to be a bit more susceptible to this phenomenon because they were not oiled as much when they were new as British planes would typically have been. A slight warp away from the fence is not a show stopper on some profiles, but on others it is. The planes on our website are carefully vetted and you don’t need to be concerned about this, but if you are buying in the larger market, you need to check the plane very carefully.
The other big issue is of course the blade. Planes that were left in a barn for the last 100 years are rarely useable. More often than not they are warped, and the irons are typically rusted beyond salvage. Don’t expect every molding plane that you buy to have a blade as that is rust free, but if there is more than very light rust on the upper edge of the blade at the cutting edge, pass on it. Again, this is not as issue that you need to consider with our planes.
Once you have bought a nice plane, there are two problems that will frequently occur with even the best of planes. Since the blade is the same width as the day that the plane was made, but the wooden body has had 100 plus years to shrink, the profile of the blade often is not quite matched to the plane. This problem is not normally much of an issue on planes of ½” or less, but by 1 inch in width is can be significant. Very often, by removing a very small amount of metal from the side of the blade, you can move it over enough to compensate for this shrinkage. It depends to some extent on the profile. Some more complex profiles do not lend themselves as well as others to this solution. Often the solution will involve both taking a slight amount off of the inside edge of the blade, and regrinding the profile a bit. This can get tricky and with some profiles, I suggest that you just leave it for a collector. One caveat: you can’t put the metal you grind off back, so do this very carefully and only once you are comfortable that you know what you are doing. If you don’t do this in 10 or more iterations, you are probably being too aggressive.
The second common issue with even good useable molding planes is that the boxing is loose and or warped. Boxing is the term used for strips of hard wood, typically boxwood but sometimes lignum or rosewood that was inserted into the profile of the plane at vulnerable or high wear points to improve the durability of the plane. The grain of the boxing is not running parallel to the grain of the plane. It runs parallel to the blade, so that the end grain is exposed to improve wear properties. Trouble is that this often leads to boxing that has warped a bit and is sticking up at one end. The hide glue that original held the boxing is usually long since deteriorated, and boxing is mostly just held in by friction. If you need to reseat the boxing, it is usually best to remove it altogether if this can be easily accomplished without breaking it. Then clean out the old glue from the slot and from the boxing. Re-glue it using very thin hide glue and wooden hand screw clamps to hold it down.
The two issues that we have just covered, shrinkage of the plane body and loose boxing are both good reasons to choose your starter plane from the suggestions that I offered. Neither the square ovolo or cabinet ogee profiles will have boxing, and in the narrow sizes that I suggested shrinkage will not be a serious issue either.
Many of the planes that we sell are sharp enough to use just as they come, but many are not, and either way, you will need to sharpen your plane at some point. With the simply moldings that we suggested starting with, sharpening is all that you should need to do. With wider and more complex moldings where shrinkage has been an issue, or with irons that have been screwed up, you might have to grind the blade first. Grinding the blade is an art. If you slip up and take off too much metal you can really screw things up. I personally use a Dremel brand hand-held grinder for this purpose. I have also spoken to old timers who use needle files to remove metal from behind the edge and then work down the edge with stone files. This brings up a good point. Only the upper surface of the iron is hardened steel, the rest, including the entire tang, is soft iron. Thus the term “iron” being used to describe the blade. I let the blade protrude slightly from the sole and then mark the high spots with a felt tip pen. Then remove the iron, grind a bit with the Dremel, and try it again. Just go slow and use a lot of iterations.
Once you are ready to sharpen the blade, a few slips are all that you needs. I personally have 4 or 5 slips that I commonly use but I could manage with just one if I had to. I routinely advise people on which slips to start out with. Don’t be afraid to ask. For lubricant, generic mineral oil is fine, or you can get Norton brand sharpening oil. One of the biggest mistakes that people make is that they obsess about “flattening the back.” These blades were hand made, with the steel being laminated to the back by a blacksmith. The back of the iron is not perfectly flat. Don’t try and make it that way now. All that matters is that you have a polished surface at the point of the edge, not that he whole back be coplanar. I just use the side of one of my slips and rub it around the cutting edge until it is polished. It is really easy.
Now, the plane is ready to try. Before you use the plane, make sure that the sole of the plane is well lubricated or you will quickly ruin it. We offer cones of bees wax for the express purpose of rubbing down the sole. You can also use clear paste wax, but it tends to wear off quicker and need redoing. Either way, stay on top of this and don’t let the sole become abraded by a lack of lubrication. It is not a bad idea to wax the whole plane overall with clear paste wax. Refer to our FAQs section for more on cleaning tools.
Setting the blade for use is a bit of an art form. I start out by putting the blade down until it feels about flush with the sole, using my finger as a judge. Then I tap the wedge in. Not beat it in, just tap it in. A proper fitting wedge that has not become contaminated with wax will hold quite well without a great deal of force. Now carefully tap the blade and test the plane in iterations until you have a setting that takes a properly thicknessed shaving. Now you can plane away. The biggest mistake that beginners make at this point is altering the angle of the plane as they are using it. Whether it is an unsprung plane like a bead, which means that it works with the plane held vertically, or a sprung plane, meaning that the plane is held at an angle off of vertical, you must keep this angle constant or you will not achieve satisfactory results. The plane will very often have “spring lines” marked on the front or rear which indicate how the plane was intended to be oriented when in use. Some experts suggest that you pick up the plane at the end of each stroke and return it to the start, so that the blade does not rub on the work piece. Others, myself included, feel that it is easier to keep your angles constant, if you draw the plane back in position, just not pushing it into the work as you withdraw it. Once the molding has taken form the depth stop will touch the work piece. At this point it is very easy to start tilting the plane further and keep cutting, thus ruining your work. It is critical that as the depth stop bottoms out you keep the plane at a fixed angle. You are finished when the depth stop is touching the board over the length of the molding. As a reward for your efforts, you should have a beautiful hand cut molding looking up at you. I hope that this brings you as much satisfaction as it does me.