Thursday, March 1, 2012

It Mysteriously Varnished

Progress is going along smoothly as I work to put the 36's control system back together. Here is the new frame in a test placement under one of the contactor boxes. I need to make a couple of small adjustments, and I picked up some hardware to make it complete. It looks like it should work exactly as intended.

And then I started varnishing the insulating blanket material with Glyptal. It soaks into the fiber, so the varnishing took most of the day. All three boxes got a first coat.


It looks good. I plan to put a second coat on soon, whenever it's warm enough again. I also want to put at least one coat on all of the covers, but that can wait until warmer weather. I should probably also coat the covers on the 309 sometime. DB-15 arc chutes open straight down, so the cover should be the only target of normal arcing, unless something really goes wrong.

And I did some rechecking of the electrical circuits, and cleaning and straightening in the workroom. And talked to Rod about getting the parts we need, such as new rubber washers. The picture above (R) gives a good view of the 1/2" bolts that hold up the contactors. We need new rubber insulators to support the contactors, and this may not be easy or inexpensive. But Rod will certainly be able to find a solution.

4 comments:

Fred Lonnes said...

Suggest you look at Fabreeka as a source of rubber washers.
http://www.fabreeka.com/
some are available thru Mill Supply Houses such as Reid Tool or McMaster-Carr

Fred Lonnes

Randall Hicks said...

Fred: Thanks for the advice. Have you guys ever tried replacing the rubber grommets on these contactors? They evidently tend to get compressed and hard with age, but it never occurred to me to look at them that closely on the 309. If the 36 hadn't been disassembled, I probably would never have thought about it.

Colin said...

Hi Randall

It's great to see how your work is progressing.

Am I right in thinking that the plate that the contactors bolt on to is insulating? I am thinking that the contactors have live frames and the rubber grommets act as additional insulation for the contactors, would I be right? I know that later contactors have quite elaborate insulators to isolate the live frames from the mounting steel work. As I remember you saying that the box was made of wood in this case, presumably, such insulation is perhaps not so crucial. Good luck with sourcing your grommets. If we didn't have the Atlantic Ocean between us I could imagine a glyptol coated paint brush in my hand. Maybe one day!

See ya Randall.

Randall Hicks said...

Colin: Yes, you are correct. The top of the box is lined with solid pieces of transite, probably the same material the arc chutes are made of.