If this is happening a little too slow for your liking, it is because I have to make sawdust all day long to keep the wolf from the door. That is 10 hours gone. Making these little planes and blogging about it is mostly a night time affair, after taking care of normal daily chores and duties!
We have made a plane body and it is looking pretty good! Time to do some metalwork.
This is what we want to achieve:
At the top is the finished plane iron, below is the material I made it from; an old HSS jointer knife.
There are four dimensions that concern us:
1. Blade width.
2. Blade length.
3. Tang width.
4. Tang length.
The blade width needs to be a little wider than the width of our finished plane body. Measure the body width and add a wee bit, say 1/16”. It can always be fine tuned later on. In the end the blade needs to stick out just a teeny bit past the edge of the plane on each side.
Blade length is determined by measuring the distance as shown in the photo. It is the length of the exposed ramp or landing that was so carefully flattened when we built the plane body.
The width of our tang must be a little less than that of the tenon or opening. Theoretically it can be a sliding fit but then everything must be perfectly square and centre. By making this fit a little loose we get some lateral or sideways adjustment. This will ensure that the blade can be set parallel to the sole with equal amounts protruding past the sides.
The 3mm (1/8”) difference as shown in the photo will be too much for a real narrow plane like the one I’ve made here (5/8”width). I think it would be fine for a larger plane. If in doubt, make it only 1/16th, it is easy to grind more at a later stage if necessary.
Obviously it needs to be long enough to go through the plane! It also needs to stick out past the wedge for ease of adjustment. As always, rather make it longer. Again, it is easy to shorten at a later stage, once you are used to the plane.
Once all these dimensions are obtained, mark them out on your blade material. Make sure the tang is centered! The HSS I used is hard stuff and nothing I have in the shop will scratch it for marking. I also couldn’t find something that would write on it. I covered it with masking tape for easy marking.
I cut with a 4” slim cutting disc in a baby angle grinder. The beauty of HSS is that you don’t have to worry about heat; it doesn’t affect the material’s properties. If you are working on an old plane blade, cut slowly and cool often with water. You don’t want the steel to get hot!
Once cut, clean the edges on a disc sander or grinding wheel. Ensure that the edges are straight, square and parallel to each other. Time to check the blade for fit in the plane and adjust by more grinding if necessary. You might need to ease the shoulders of the blade for a good fit. Then grind the primary bevel to 25 degrees. I do this on a bench grinder with shop made adjustable rest to get the angle perfect.
If you are using carbon steel, KEEP COOL! Not you, the steel :^) Have a container with water handy and dip very often.
A few swipes on my whetstone to establish the secondary bevel, some polishing with the strop and we are done! I know some likes to use sandpaper for sharpening. Whatever works for you!
Next we’ll make the wedge and fine tune our plane. In the meantime, why don’t you shave with your new blade tomorrow morning!
-- Div @ the bottom end of Africa. "A woodworker's sharpest tool should be his mind."