The Stovebolt Site Forums The Shop Area The Electrical Bay The AD Heater Toggle Switch Born Again Saga!

The original heater toggle switch was a little erratic and just wasn’t smooth when I switched it. I dint want to replace it with on of those rotary heater switches that the vendors are selling, so, I commenced to opening it up and see if I could restore it.
Wasn’t that much of a problem and all that was wrong with the insides was that the grease had dried out, caked up and causing the contacts to be erratic. A good clean up, re-lubrication of the detent and a new rivet and it was back working like new. On the outside the wire wound resistor, which is supposed to be potted with a ceramic coating had lost its coating. The ceramic coil form was loose in the coil so I mixed up some porcelain, which I just happened to have on the shelf, and repotted it. Of course I couldn’t fire the porcelain so after it had dried a good soaking with super glue appears to bind it together just fine for now.
Here is a picture of the reassembled switch and scrolling back a few shows the disassembled switch and potting.
http://rides.webshots.com/photo/2086740890098611668iVAzNn
Denny Graham
Sandwich, IL

Nice going Denny!

Nice repair job. Was the wire on the coil covered before with some potting agent...it looks like it was bare to me. Why did you cover it and how long will it last?

Won't it get darn near red hot, move around and cook your crazy glue/ceramic coating?

I would have thought that with the resistance wire open to the atmosphere, it would dissipate heat much better.

I'm sure I don't know the whole story.

Stuart

Stuart that was one of my first-involved questions on this site. I agree, thinking it would get to hot, on low, I burnt the heck out of my fingers ONCE! At least I learn quick!

Most of the coating is off mine which is probably why it burnt my fingers... I imagine the coating is more of a protective measure to radiate the heat better without getting as hot as the element by itself would.

Very interesting... Denny let us know how it goes!

Jeff

Thanks guys,
The resistors are made like a standard electronics wire wound resistor, i.e., they are potted in a ceramic. If you look inside the coil form and around the base of the leads you can still see some of the material that didn’t flake off. I've never seen a wire wound resistor that was bare, too much of a chance of it shorting. They typically are used where a lot of heat is to be dissipated, as in the heater switch where the resistor is dissipating roughly 15w. The reason these get so hot is that they are sized just big enough to handle the load and not any bigger. You could replace the resistor with a standard modern day power resistor rated at .5 ohms 15w but it would be a larger resistor and not get all that hot.
Don’t know how the potting is going to hold up Stu, got any suggestions? This is all an experiment so time will tell. Like I said, I couldn’t fire this resistor after potting it with the slurry, and I couldn’t find the coil forms to make new ones, and in fact couldn’t find the proper eyelets for this application either. I can’t get hold of Stimpson by phone and they won’t return my emails. They have the market cornered when it comes to eyelets. Luckily I have a small supply of eyelets still in my inventory that covers most of my repairs but they are running thin and none that would work in these switches.

Denny Graham
Sandwich, IL

Wait till ya see what I been doin’ with the original light switches.

I would think if it gets red hot that heat would melt the black housing as it's plastic and not bakelite, at least i know mine is the last time i looked at it. (that's been several months ago and put away. I liked the previous shots (in your photo link) of the switch taken apart. The info is great denny. thanks

I LOVE your shop
&&
the tip on the rebuild

Wrong Jim, this one is Bakelite. That's the problem; I was looking into making some reproduction switches since no one is making one. If I did it, it would have to be an exact replica and the Bakelite is the brick wall. I have been trying to find a source for black Bakelite raw material for a long time with no luck. If it were just thermoplastic I can find that everywhere. I could do it in the Bakelite in small quantities using a hydraulic press but like I say, I can't find the raw material. The white switch lever is a thermoplastic.
The inside parts are pretty simple, brass contacts and phosphor bronze wiper and detent.

If you replaced your switch with a new one and want to get rid of your old one, let me know, anyone!
Denny Graham
Sandwich, IL

Hey Denny thats advertising!!! :mad: Put it in the swap meet area!

(Besides, Id want one to... )

Nice Work Denny !
Hmmmmm Denny send me a message we will chat on the bakelite ...My parts guy at the plant has lottsa connections he gets us the brown Bakelite for lottsa things at the plant in any thickness we want ..maybe he can hook ya up with black ???
Tim

Believe me Jeff, I'm not lookin' to exchange any money here. I'm playing grave robber, like those body snatchers Burke and Hare in Edinburgh, I'm just looking for burned out cadavers. Seems like most of the old failed switches just get thrown away when the new one arrives from Jimmy Carter. I want to try making new contacts and wipers for them but I need some old ones to experiment or practice on. I’m hoping to be able to do the same thing with these the light switches also. Haven’t got the light switches completely figured out yet but I’m getting there. Here’s a taste of how I’m coming along with them; http://rides.webshots.com/photo/2440156710098611668AhSEYh
I worked on winding new rheostat elements with Nichrome60 yesterday and have run into another brick wall in getting the eyelets. My small supply of eyelets has about run out and can’t find a supplier. Stimpson over in Bayport, NY is the only manufacturer in the game, they have a monopoly on the eyelet market and I have been unable to talk to anyone there by phone or email and I’ve been trying for two weeks. I was forewarned by a couple of other rivet companies about their independence, and am finding it true.

Tim, I’m not looking for cured phenolic, what I need is a few pounds of the raw black granules/powder. I can't find it anywhere, can't even find books on it. I want to make my molds, use my 50 ton press for pressure and apply heat to cure the thermoset. Not a high volume way of making components but I could turnout a few every night after supper like this. Injection molded thermoplastic has pretty much replaced the Bakelite in many applications because of the speed, cost of dies and other equipment. Some of the new plastics can even stand the hi-temps almost as well as the Bakelite.

I'm on a tight time schedule right now cuz all this bench work is gonna have to stop as soon as the weather breaks. Like the tulips, I start to bloom in the spring. So when it's warm enough that I don't have to wear the snowmobile gloves to work on the truck I shut things down in the basement and start working above ground, no more experimenting till next winter.
Denny Graham
Sandwich, IL

i'll have to go locate my box of electrical stuff and see if mine is bakelite
hummmmm can't remember. it looks like yours.
haven't been that box for some months since i'm waiting on the paint shop AGAIN
but i'll have to find my old one anyway when the interior electrical gets done ...
he's still got my steering column..... guuuurrrrrrrrrrrrrrrrrrr

Just curious--I thought the fan switch was just an on/off switch; why does it have the resistor?