Wednesday, March 23, 2016

Making strike knob buttons

On old English planes, especially the longer ones, you often find a strike knob on the front part of the stock, made from wood. On Dutch planes you find similar strike buttons, but they are invariably made from steel. I had an old, worn out plane, and I sacrificed it to get hold of the button so I could replicate it. Here is how I go about making them.

First on the lathe I turn a spike-like shape, but still in the round. I don't turn to a point, that comes later.

Then I use a large bastard file to create the flats, so the result goes from round to square. Still in the lathe, not rotating of course! The four jaw chuck gives a nice visual to make the square as square as possible, allthough I don't pretent it turns out perfectly. Counting file strokes helps to keep everything more or less symetric. First I file the straight part.

And then I file the tapered part. this also brings the spike to a point. When you don't leave enough material when turning, this step will strongly shorten the spike.

Then I turn it around in the chuck and shape the head. Rough shape with the lathe tools, then refining the shape with a file. (a sacrificial washer behind the head to protect the chuck).

When I am happy with the shape I bring it to the vise and use a hammer to give the head a hammer finish. Which means hammering the surface to create small facets all around.

And that's one finished strike button. After this I will heat it up with a propane torch to cherry red and let it cool slowly to give it a nice black color. Finish with linseed oil.

Here is a strike button on the front of my new jointer plane. You hit it to retract the blade or you hit it very hard to loosen the wedge.

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