Monday, June 15, 2009
Josh's Saw Rehab
Okay, so the other day I am over at my brother Josh's place and there is a saw hanging on the wall. I recognize this saw. I once tried to use it when I was helping him build a deck. It was awful. Dull to the extreme. I ask him "Hey, do you actually use that thing?"
I take it down. I touch the teeth. I run my finger down the teeth with more than a little pressure. Egads man! You'd have better luck trying to saw a board in half with a row of dimes!
"Do you want to sharpen it?" he asks.
"While you're at it, maybe you can make a nice wooden handle for it too," he suggests.
I'm thinking "No way do I have time for that!" But the seed is planted, and hey, he is my brother...
It's a Sandvik - not much of the etch left, just part of the name, "ship point" and most of the image of a ship under sail.
When I removed the saw nuts (two were actually machine screws) I got a surprise - "Hidden Dragon!" What the? The metal plates are original, and the handle clearly has recesses made for them, but underneath are more dragon designs. Why?
I thought about changing the handle design to more of a Disston pattern, which I like better, but decided to just reproduce the existing handle. I dug up some 4/4 Alaskan birch and traced the handle. (That's not a crack in the wood, it's an old gauge line from some forgotten project...)
Using a brace and bits, I bored the holes for the saw nuts and removed most of the waste from the hand grip. I was really an idiot here, but I didn't know it yet...
Bow saw time!
I used a rip saw to cut the kerf that houses the blade in the handle. The original handle had a curved slot to fit the curved end of the blade. I just went ahead and cut a straight kerf that will show on the top edge of the handle for a few inches.
Shaping the handle was a bit of chore. One problem was finding a way to hold the work piece but still allow access for the rasps I was using. I think next time I will leave a long strip of wood attached to the handle for clamping purposes, and then cut it off when most of the handle has been shaped. For this go around, I dug up an old vise rig I used way back before I made my shavehorse. It's just a small bench vise mounted to a 2x4 that clamps into the face vise. It worked pretty well for this job.
Now back to the idiot part. When I bored the holes for the nuts, I used the wrong size auger bit. To fix this mistake I couldn't use another auger bit, as the lead screw would have nothing to hold it. So I rebored with a standard twist bit in the brace. This worked fine, but I made my second mistake and forgot to clamp a backing piece to the handle and as a result, I got some nasty tear-out. Arrgh!
Now I had to try to patch these. After crawling around on the shop floor and digging in the chips, I actually managed to sort out several of the missing chunks. For the others I cut small pieces from the cut-offs from shaping the handle. I glued these in place, clamped them up and put it aside to dry while I sharpened the saw.
I tried something new on this project. In the past, when I have sharpened saws and wanted to darken the teeth to more accurately see what is happening with the file on the teeth, I have used a magic marker. This never worked very well - it was slow, did not provide full coverage, and destroyed the marker tip. This time I used a much simpler technique that worked incredibly well. It was fast, provided full coverage and required only one special piece of equipment:
I couldn't believe I had never tried this before! So easy! It was great! Now, first I had to reshape the teeth, and for this operation I didn't need any blackening; the teeth were already very dark from age. But after shaping, when I wanted to sharpen the teeth, I really needed the blackening to help me see things. Here's a shot of the saw after reshaping the teeth, showing the difference between the unblackened shiny teeth and the blackened teeth after one pass through the candle flame.
And here's an end-on shot after sharpening one side. It is very easy to see which gullets/teeth have been sharpened and which have not. I will definitely be using this technique from now on.
Back to the handle. The patches had dried and I carefully reworked the openings with a sharp knife. Not too bad.
I decided to stain the handle dark - it just seemed like the right thing to do.
While that was drying, I made a blade guard. I ripped a kerf down a narrow piece of wood from the scrap bin. This saw has a pronounced belly to the blade - the edge with the teeth is convex. In order to keep the blade from rocking I needed the kerf in the guard to be deeper in the center. I achieved this by alternating cutting with the first couple of teeth at the toe of a saw, and scraping with the corner of a flat bladed screwdriver.
After the stain dried, I put on a coat of amber shellac...
...and then a liberal coating of my own mineral oil and beeswax mixture. The results were not too bad. I probably should have spent more time on final shaping, but I think the results are satisfactory.
I couldn't decide whether to reuse the metal plates or not. I decided to let Josh decide. I didn't have any true saw nuts, so I used some European cabinet fasteners. Not traditional, but they work. Here's the rehabbed saw without the metal plates:
And here it is with them:
Josh chose the "with" option. Here's one last comparison between the original plastic handle and the new wooden one:
A fun project. I enjoyed replacing the plastic with wood and bringing a tool back to life, and I added a new technique to my saw sharpening repertoire . Plus, it was for my brother, so it's all good!