The leather treadle belt on my Singer 328K was slipping when I sewed over anything thick or used twin needles. I tightened up the belt, but even with the belt tight, it was still slipping. I think there were a few things causing it to slip. The main reason is probably because the treadle belt is scraped up from when I was using the belt with the original balance wheel and there wasn’t quite enough clearance for the belt. Another factor is that I have it on a treadle base with a large wheel to make it treadle a little faster. Also, it is a zig-zag sewing machine, which requires more force to turn than a straight stitch machine.
Someday I’ll replace the leather belt with urethane belting, which I think will work better than leather for this machine, but for now I just wanted to put something on the belt to make it stickier. I figured violin rosin would work. I planned to buy some, but then I thought, hey, rosin is made out of pitch, right? I live in a house surrounded by pine and fir trees, so maybe I could make some rosin? Rosin doesn’t cost much, but I thought it would be a fun project to try to make my own.
A Google search gave me an idea of how to make rosin. Basically, you boil pitch, then add beeswax and other secret ingredients. I didn’t find any actual recipes (I guess that’s top secret info), so I just winged it.
There is snow on the ground at my house and it’s been raining, so I didn’t really want to go tramping around in the slush looking for pitch. I remembered that I had some pitchy firewood, so I decided to try scraping the pitch off of it, since I only needed a little bit of rosin.
I put the pitch in a metal measuring cup and set it on the wood stove to melt and boil a bit. I added a couple of small chips of beeswax and stirred them in.
I made a mold out of pieces of a manila folder, poured in the hot pitch, and let it cool.
I regretted using my good measuring cup when it came time to clean it up. I had to heat up some rubbing alcohol in it to dissolve the pitch then rub the cup with coconut oil, but I got all of the pitch residue out of my measuring cup.
The rosin came right out of the mold. And what do you know, it kinda looks like a tiny piece of rosin!
I rubbed the rosin on the leather belt as I treadled until the belt felt just a bit sticky.
The belt is slipping a lot less now. I had fun making the rosin, and it didn’t cost me anything to make it, so I got double enjoyment out of the project.