Saturday, February 20, 2010

Back Story on the Shave

A while back, I bought a small wooden spokeshave blade with the intention of making a spokeshave. I bought an gabon ebony blank, and went to work. I worked on it on and off for a while. One thing I have to warn any wooden spokeshave makers is to not use such a hard and unforgiving wood (such as ebony) for your first shave. At one point I managed to crack the entire front portion off, luckily I was able to repair it seamlessly. On the other hand it makes such a nice shave, the ebony is very hard and dense, so it beautifully takes a polish. This was the first time I had used ebony like this, so I wanted to make sure to not mess up the finish. So I consulted my fellow galoots on woodnet to see what they thought. Here's what they came up with:
What Finish for a Ebony Spokeshave
I chose to go with a combination of buffing, shellac, and wax. This is a picture of the finishing products used. A buffing wheel charged with brown tripoli (it looks green because I had been using green honing compound prior to the tripoli), dewaxed shellac, and wax. Technically I should include alcohol because I used it to thin the shellac, but I forgot. First I sanded the shave up to 600 grit. Then I buffed it with the tripoli, until it looked good. Then I put on three coats of about 1 part 2 lb. cut clear shellac to 2 parts alcohol, buffing in between. The final layer is a coat of wax, also buffed. I'm really happy with this finish, I plan on using it on more tools.

Now to the blade. The blade comes dull. The bevel and the bottom do not totally meet at the cutting edge as can be seen by this highly advanced drawing:
This is what is wanted:To achieve this you must grind away the excess to make the sharp point. I did this freehanding it on my grinder. This is a drawing of the most desirable situation. Usually on a conventional blade I would do this step with my honing guide and coarse diamond stone, but the spokeshave's threaded posts prevented me from doing any serious grinding on the bevel.As you can see, this makes the non-beveled side become like a hollow ground blade on a conventional blade like this:

The advantages of the hollow grind are that it reduces the amount of steel that needs to be taken away to sharpen, which makes the process quicker. After doing this to the bottom of the shave blade, I was able to achieve a sharp edge.

The blade I bought from The Japan Woodworker came with a photocopy of David Charlesworth's article on making a spokeshave. Unfortunately they didn't actually photocopy the entire thing, so I had to go to the library and rent the book the entire article is in. I also used this article by John Gunterman. Both were very helpful.

This tool will prove to be very useful in upcoming projects.

1 comment:

Bob Rozaieski said...

A good solution indeed. Old wooden shaves often have a similar hollow forged into the "flat" face of the blade.