DavidLG4527 August 2021 at 07:37 #53335
Does anyone have any experience of repairing these battery covers?
When I got these I was told they were bakelite but I’m not convinced they are.
The cut outs for the cables have been hacked about and I would like to tidy them up.
Any suggestions on what to build up the missing areas and what will stick to the base material appreciated.
Davidh1427 August 2021 at 09:03 #53336
Wow David, where did you get those?! Are any more available?
The covers won’t be bakelite, which would be rather too brittle. They’ll be the same material as the battery cases were, a very hard rubber compound. The plates were held in with pitch, which clearly attaches pretty firmly. I would imagine Isopon/Plastic Padding type fillers would work well, you might even be able to add colour (soot?) whilst mixing, otherwise paint to match. You would need to clean and roughen the damaged surface first.
LaurenceDavidLG4527 August 2021 at 11:03 #53337
Ebay – they come up occasionally.
I don’t think they’re hard rubber. I have a pair of hard rubber batteries and they don’t feel like that at all. They have a very hard surface. If you tap the covers they sound like a pottery flower pot sounds and I suspect if I hit one with a hammer it would break as a flower pot would. I have been told they do shatter. Not going to try it. . . .
Davidh1428 August 2021 at 09:14 #53338
The word “vulcanite” springs to mind. i’d be surprised if these weren’t made of the same material as the original prewar battery cases, unless a cheaper material justifying its use. Yes, I’m sure they would shatter, given the opportunity!
Off to search ebay ….
LaurenceDavidLG4529 August 2021 at 09:59 #53339
I think you’re right. I was comparing it to a modern hard rubber cased battery which of course would be made from an entirely different material.
I looked up Vulcanite:
In 1839 Charles Goodyear discovered the method of mixing sulphur with rubber to form hardened or vulcanised rubber, called Vulcanite. The proportion of sulphur can be increased or decreased in order to vary the required amount of hardening accordingly. Between 25-50% sulphur gives a hard product with the familiar feel of plastic. . . . Vulcanite could be produced in almost any colour, although the predominant colours are black (ebonite) and brown. . . . Vulcanite is a thermoset material which, after moulding becomes brittle and cannot be remoulded.
I will do some experiments colouring plastic filler. I have some black pigment powder for colouring cement which hopefully will do the job. Soot is hard to come by these days. . . .
DavidDavid Bracey29 August 2021 at 18:30 #53340
Here you go if you fancy a bit of diy
Davidh1430 August 2021 at 09:55 #53341
More for repairing inner tubes than batteries, but what an amazing survival! Especially with such complete paperwork … that belongs in a museum! Someone got a bargain, at only ?6, but surely of no use today. Never understood why hot vulcanising was necessary, when rubber cement and patches work perfectly … perhaps the adhesives weren’t much good back then.
LaurenceDavid Bracey30 August 2021 at 20:14 #53342
Yes, just an interesting find. Not seriously suggested as any use to you.
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