Two Coats of PolyShade on the Tonearm
Recorded on March 20th, 2016
Even though this tonearm is a proof of concept, I’m taking it as far as I can before making a new one out of cocobolo. This weekend, I bought a can of Minwax PolyShade (American Chestnut), and some ultra flexible 320-grit 3M sandpaper. The goal here is to put as many coats as the tonearm needs to give it a better “transmission layer” in the form of a poly/stain shell. I don’t know if it’ll work, but I’m inspired here by a message in this old 12” DIY tonearm thread on Lenco Heaven:
First I tried listening to this contraption in its “pure” form, with no sealing or finish applied to the wood. Well, it was predictably horrible. Then the rod was sealed with shellac, and a few further thin layers of it were applied. Shellac was chosen because of its ease of application, quick drying and hardness of the surface film.
After 2-3 layers the sound started “opening up”. It was better than raw wood, but still “tolerable” rather than “good”. 5 layers — aha, it’s singing again! In the end, I put something like 10 layers of shellac and a couple of very thin wax layers on this stick.
How does it sound now? Well, it has completely dried up and settled, and to my ears it’s at least equal to the original aluminium tube “Sorta-fon”. I was surprised that something made out of cheap and very common wood can do so well. The “transmission layer” of shellac really changes it.
I’ve never stained or sealed wood before, so I have no idea what I’m doing. I’m using a very light touch with the 3M sandpaper between layers, and since each coat takes six hours to dry, it’ll take days to get to the point where I can put the final wax on it. I’ve never seen anything like the 3M 320-grit ultra-flexible paper. It feels like sandpaper from the future.
I read a lot about how steel wool is the greatest thing ever for getting a smooth finish on wood, but the more I looked into it, the more warnings I saw about how steel wool sheds. It’s probably great if you’re refinishing a dining room table, but I don’t want any metal bits dislodging from the arm and getting into the cartridge or falling into the LP grooves. If Home Depot had had synthetic steel wool, I would have bought some. Instead, I’ll have to get some Norton 0000 synthetic steel wool from Amazon.
More later as I add on layers of PolyShade. I’m beside myself with impatience because I also bought a new “bearing” in the form of a tungsten carbide glass scriber tool (shown in the photo above). It seems like it fits the hex head of the bolt in the tonearm well, but I won’t know until I’m done with all these varnish layers.