Sunday 23 June 2013

Prototype Coffin Smoother

Of course I have a “bucket list” of planes that I would like to make and I have for some time wanted to make a small version of a traditional coffin smoother. My idea was to make a smoother with a 1 1/2 inch wide blade and between 5 1/2 to 6 inches long. I do not own any traditional, unhandled, coffin smoothers so the design proportions were up to me. I have, in the past, used the “compose as you go” method successfully on several woodworking projects. However, I do not recommend this method for plane making. Accurate drawings are a must. After drawing the plane, I can usually feel confident that the proportions are going to work. I make planes to use, so for this plane I also needed to make a mock up infill out of some scrap pine.

Prototype of coffin smoother

Steel dovetails on coffin smoother

Finished steel coffin smoother with Ebony infill, 1 1/2" wide blade & 5 3/4" long body

For those of you that are new to infill planes then you will notice from these photos that when you dovetail a steel sole and sides together, then the dovetails disappear. When I first became interested in infill planes I could never imagine going through the labour intensive dovetailing process and in the end not see the joints. I have always been inspired by the work of plane maker Konrad Sauer of Sauer and Steiner Toolworks. He opened my eyes to the fact that certain infill woods marry beautifully with the clean, crispness of 01 tool steel, and of course ebony is one of these woods.

This plane is coffin or curved shaped, which of course is a great deal more challenging than a parallel sided plane. Fitting the infill is one of those challenges and it takes patience to get it right. The infill has to be tediously hand fit. It makes an amateur plane maker like me really respect the guys that do it for a living. In the end I am happy with the fit of my infill.

Front infill detail

Rear infill detail

I am trying to keep the corner detail crisp, where the steel sides meet the steel base. The close up photo of the front shows this. I missed the mark on this detail on my last plane, which annoyed me to no end. If you look at other plane maker’s websites you will see that this detail gets approached in various ways. Aesthetic details are important to me however, when I am making a plane the anticipation of taking that first shaving is my biggest priority.

I am happy with this plane. Of course it is not perfect. That will never happen. Next time I would change the shape of the lever cap a little and I also need to work on my finishing. It does not have the one handed versatility of my small, low slung smoothers, but it is nonetheless very comfortable to use. I am looking forward to making this plane with brass or bronze sides and because you see so much of the infill this plane design is great for showcasing beautiful woods.