Re-handling a tanged chisel is a little more complicated than re-handling a socket chisel. But it is not above the capabilities of the average woodworker. If you can turn wood then you can accomplish this task.
Select a blank big enough to make the handle you want and an inch or so longer than you need. The wood can be just about any hardwood that you like. I find ash, hickory, and hornbeam to be good choices, but certainly not the only woods that would be suitable. The blank needs to be milled straight and square with ends perfectly square to the sides. If this is not possible, as in my case where I am repurposing an old hickory maul handle, you must round the blank between centers and then cut the ends square to the blank. This is necessary to ensure that your handle blank is parallel to the drillpress spindle which will produce a chisel handle that is straight to the chisel.
The tangs on chisels are most often of rectangular cross section and taper from the bolster to a point. Three different sized holes are usually sufficient for a good fit. However if the tang is unusually long you may need four or more different sized holes. This chisel has a 2 5/8″ long tang and three holes are fine for that length. Using dial calipers, a micrometer, or some other accurate means of measurement, measure the narrow width of the tang about 1/4″ from the point. Select a drill bit this size. Then measure the narrow width at about the midpoint of the tang and again about 1/4″ from the bolster and select the appropriate drill sizes to fit these measurements. Next layout, and mark on your handle blank, the depths of the three drills. The depth of the smallest drill should be about 1/8″ to 1/4″ deeper than the tang is long, approximately half the length of the tang for the midsize drill and about 1/4″ from the end. Now it is on to the drillpress.
Start with a center drill big enough to drill a center whose diameter is just slightly bigger than the measurement across the widest points on your tang at the bolster. The object here is to leave enough of a center to engage your tailstock live center after final fitting of the tang into your handle blank. Now drill the holes starting with the larger drill, then the midsize drill and finally the smaller drill.
Now it is time to get out your propane torch. Put the chisel in a bench vise and hold it near the bolster. The mass of the vise will wick off much of the heat minimizing the possibility of taking the hardness out of the chisel. Put the point of the inner blue cone of the torch flame to the base of the tang. Work the flame all around the tang and up and down its length. You want to concentrate the heat on the base of the tang because this is where most of the metal is. You do not need to get the tang cherry red. In fact you don’t want this as this may take some of the hardness out of the chisel. You only need to get beyond the flash point of the wood which is about 570ºF. When you move the flame up to the point of the tang and you begin to see the metal turn slightly red it is time for the first burn in.
Set the torch down being careful where you point the flame. Put the handle blank over the hot tang and slowly bring it down over the tang being very careful to keep it straight in both planes (front to back and side to side). Keeping the handle blank straight is very important because you cannot correct it if you go too far out of straightness. Stop when you feel the resistance begin to get firm and remove the handle blank and mark the orientation of the blank to the tang. Chances are you have not seated the blank all the way home yet. Cool off the chisel in water and reheat the tang and do the whole operation over maintaining the same orientation as before. Do not try to force the blank down onto the tang. Always stop when the resistance gets high. You will probably have to repeat these steps several times until you get the blank seated to about 1/16″ from the bolster.
The next order of business is to cleanup the newly burned in mortise. I use 3 corner Swiss needle files for small tangs like this one, but small chisels might also work depending on the size of your mortise. The object here is to get the charred debris out of the mortise and to bring the fit just a little closer to the bolster. At his time you can also do some minor correcting of parallelism between the face of the handle blank and the mating face of the bolster. however, if these faces are not parallel or very close to it after the burn in you will have to make a new blank and start over. Don’t feel bad. It has happened to me before.
Turn your handle to whatever pattern you like. Fit the ferrule. and apply your finish of choice. I like boiled linseed oil and carnauba wax for my chisel handles.
When your new handle is finished hold the chisel vertical with the edge on a piece of hardwood on a solid surface. Keeping the handle in the proper orientation to the tang place it on the chisel and give the handle a firm whack or two. This should seat the handle firmly on the bolster. I find a dead blow mallet works well for this but you could use a piece of softwood and a hammer. You now have a chisel ready for another generation of service.
As always, thanks for stopping by and feel free to leave a comment.