How to tune up Grandpa’s old iron plane
At least once a week, someone tells me that he (or she) has an old iron hand plane that belonged to a grandfather, father, uncle, some other relative or friend. After repeated attempts to “shave” wood with the instrument in question, the owner concluded that there certainly must be something wrong with the darned thing.
The truth of the matter is that in 99.9% of these cases, the “un-usability” of the device is a matter of operator error. (Or as the golf great, Ben Hogan said, “it’s the indian, not the arrow”.) A plane is a deceptively simple device. It is after all, nothing more than a blade, supported by a rigid body. The basic design hasn’t changed in several thousand years.
So, we’re going to rehabilitate your old plane, step by step. We’ll concentrate on the Bailey patent design. This is the type of plane that most woodworkers are familiar with. Stanley, Sargent, Record, Kunz, Sandusky, Defiance, etc. all made planes based on Leonard Bailey’s design. There are some other types, namely Sargent’s Accu-Set planes and Stanley’s Gage planes that are departures from Bailey’s adjustable frog design. But, most of what we’ll discuss here will apply to these planes, as well.
We’re not going to consider the arcane minutia here, just simple, straight-forward, how to get the job done. Here we go.
1. Most bench planes have suffered some damage around the perimeter of the sole and the mouth. These dings will leave “tracks” when you’re planing, so we need to get rid of them. File a small chamfer around the perimeter and “draw file” the back of the mouth. Be very careful around the mouth as we don’t want to increase its size, unless it’s absolutely necessary. (Remember when drawfiling that the teeth only cut in one direction, so make sure you’re going the right way.)
2. With the iron in place, flatten the sole of the plane by “lapping” it on a flat surface such as a heavy piece of float glass, granite gauge block, cast iron jointer or table saw. Leaving the iron in place will put “normal stress” on the plane body. Remember to back off the iron. 400 grit wet/dry paper is a good place to start. Don’t go too fine. Remember a polished sole looks good but as it increases surface contact, it also increases heating and energy required to do the planing (that’s why corrugated soles were developed). Contact areas will “brighten” during the lapping process. The goal is to insure contact at three points; the toe (front), the mouth and the heel (rear) of the plane.
3. Insure that the frog is properly seated by running a bastard file across the bed. Ideally, the upper and lower edges of the bed will “brighten”. This indicates that the iron will seat firmly on those two points when the lever cap is tightened. If the center and one edge brighten first, the iron will not seat firmly and it will be prone to “chatter”. In this case the frog should be filed flat. THIS TASK MUST BE COMPLETED WITH GREAT CARE AND PATIENCE to avoid creating a surface that is distorted.
4. Clean and lubricate the plane.
5. Determine the type of planing you’ll be doing and establish the amount of crown you want on the iron. Shape, hone and strop the iron. See earlier articles on sharpening and crowning in the blog.
6. Insure that the chip-breaker is making correct contact with the iron. Set the chip-breaker back from the cutting edge around 1/32″. Remember the mouth opening is the determining factor in shaving thickness, not chip-breaker position.
7. Re-assemble the plane and adjust the mouth opening (by positioning the frog) to allow the passage of the maximum shaving thickness that you intend to remove with this particular plane.
After a little testing on some scrap, you should be getting results that rival those from any $300.00 plane on the market today.