Larry Williams
>David, I'm glad you feel you had success with this. There are reasons, though, I would avoid it.

Most importantly, these old planes are the product of hundreds of years of evolution. Even the shape of the coffin smooth plane contributes to its stability. Wood selection is important to, beech is used and oriented such that it rapidly moves moisture to and from the core of the plane. Interfering with this is, IMO, like gluing panels in place when using frame and panel construction--it defeats the whole design.

Linseed oil also expands as it dries similar to other oil finishes I've used on planes. When absorbed into the ends of the rays which are exposed on flat-sawn surfaces, it can cause checking as it expands when drying. I found it terribly frustrating at times to lose a plane to finish expansion. Too see how much linseed expands, pour a little in the bottom of a jar and let it dry. It won't dry to a smooth surface, the surface will be heavily alligatored by ridges formed when it expanded and was pushed up.

Linseed oil supports fungal growth. My first bench turned almost black after a few years and was finished with boiled linseed oil. Looking at 19th Century planes that have had this treatment, one finds that same fungal growth as well as a layer of dried leached out oil on surfaces that weren't subjected to wear. This is especially true of end grain surfaces. I've seen instances of it covering the bed of a plane where it created problems with seating the iron after the iron has been sharpened down a little from the length it was during the initial treatment.

What I want in a finish is a relatively permeable coating that protects the wood. Just a couple coats of a nonexpanding oil with a light sanding between them and a good buffing of the final coat will allow sufficient moisture to pass through to allow a beech plane to quickly reach equilibrium in changing humidity. It's a little like frame and panel construction, the idea is to work with the wood instead of fighting its properties.