ZK Project Notebook

With the plane set to take a not-very-thin shaving, the mouth is 0.006” (six thousandths of an inch, a sheet and a half of paper). Paradoxically, the deeper the cut, the smaller the mouth gets (since the bevel gets thicker as the blade is pushed into the mouth).

You can see that I’m not all that concerned with a polished sole. This was flattened on a medium India oil stone. I start out with PSA (sticky backed) sand paper on a flat surface but I’ve never gotten anything truly flat that way so I finish up with other methods (such as the oil stone, diamond plate or sand paper on a long stick (better control of material removal)).

Jeez, I hate waiting for finish to dry. So I didn’t and started to use the plane. Made some much needed ergo improvements. Verdict: it sure works well. In this photo, I’m planeing a chunk of oak flooring against the grain. No tear out and a very smooth surface.

Next up: birds eye maple flooring (yes, birds eye maple flooring. And this is scrap from a job that involved thousands of square feet of it). Here we have a 55º bevel down smoother (2” x 1/4” iron) and a 55º bevel up smoother (1 1/4” x 1/8” iron), both set to approximately the same depth of cut. As far as I could tell, no difference, both were able to do a very nice job (ie very smooth, no tear out, finish ready).

Got all the pieces but it is in the “hurry up and wait” stage as I apply the finish and let it cure (lots of coats of oil/varnish). Then, finish lapping the sides and sole, open the mouth and do something with the cross pin (either leave it as a press fit or put screws at the ends).

I tried something new for tempering the blade: flux. Very hot steel and oxygen are a bad mix as the oxygen “robs” carbon from the steel and can leave the surfaces (like the cutting edge) weaker. This is why, sometimes, you need to sharpen a few times before the edge starts to hold up like it should. And, maybe, why the corners tend to crumble no matter many times you sharpen. The best cure is to use an inert gas filled furnace and quench so the steel never sees any oxygen. Way out of my price range however and I’m too cheap to send the blade(s) to a real heat treater. There is also a stainless steel “tool wrap” you can use (again, expensive). So I tried using brass brazing flux to cover the blade. As far as I can tell, it worked great – it didn’t interfere with the quench and the steel was clean (as in bright and shiny, no oxidization).

Ahh, winter. The time of the year when pumpkin pies and good cheer abound, I freeze my tushie riding my bike, epoxy doesn’t cure and finish doesn’t dry. My shop spends the winter in the fifties (ºF, well insolated but no heater). the epoxy I’m using cures at above 70º. What to do? After a bit of cogitating and experimenting, a light bulb went on, so I grabbed it and put it to work. I have a 25 watt bulb in a work light sitting on an insolating pad (don’t want a fire) in a small cooler. I change the bottom opening to control the temp, it hovers around 100º.

If you make one of these, be sure and check, check, check the temp. A dimmer would be nice but I didn’t feel like buying one. I started with a 100W bulb and the temp was probably pushing 200º.  Which is past the point where PVA glues melt and epoxy fails.

While waiting for the infill finish to dry, I decided to work on the cap screw. Steel, brass, turn as one piece … ? I thought I’d try something that should be quick and easy, just Loctite a cap screw into a brass cap. So I turned the head of a 5/16” cap screw to just over 7/16” (to get down to bare metal) and trimmed the head length to about 1/4”. Then I drilled a hole in the end of a brass rod and used a end mill (as a drill bit) to get a 7/16” flat bottomed hole. Then a test fit. Which didn’t want to come apart, I guess I don’t need Loctite. Pressed it home and called it good. It is good enough that I was able to machine the brass by holding the screw.

I think next time, I’ll just trim the head length and leave the diameter alone and bore the brass for an interference fit. The drill chuck isn’t all that rigid and the end mill wiggled a bit on entry.

I knurled around the corners (the knurl is rounded, not flat) by holding the knurling tool at various angles to the edges and to flatten out the ridges that created. A little work with a brass brush cleaned things up quite nicely. Lots easier than making a custom knurling tool.
The top is shaped so as not to dig into my palm, wish I could think of something more stylish.