Joined: Aug 2017 Posts: 142 Threads: 29
Reputation:
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Location: New Forest
Car type: 27 Chummy
Hello All
My BLIC magneto cap is absorbing moisture and making it very hard to start. Resistance as low as 20 Meg, leaking the HT spark.
Baking in the oven restores the performance. Is there a way of waterproofing the bakelite or using EHT spray etc to prevent absorption. New caps do not appear to be available.
Many thanks.
Adrian.
Joined: Aug 2017 Posts: 557 Threads: 89
Reputation:
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Location: Deepest darkest Kent
Adrian,
some Blic distributor caps are a brown and some a reddish colour. I suspect the reddish ones were painted with a red insulating varnish when new.
Once you have cooked the cap and removed as much moisture as you can. You can use a hygrometer to check how dry you have got it.
Then I would try a high voltage insulating varnish. Varnish inside and out and when completely dry clean the contacts inside.
Hope this helps.
Joined: Aug 2017 Posts: 381 Threads: 16
Reputation:
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Location: Port Elizabeth, Sunny South Africa
Car type: '26 Chummy, '28 Top Hat, '33 Type "65", single seaters
Adrian a good soaking of DWF (De Watering Fluid) aerosol spray should sort it out, it's made for spraying electrical stuff, I've soaked dizzy's with it, inside the cap as well. It dries off and repels water.
Aye
Greig
Joined: Aug 2017 Posts: 142 Threads: 29
Reputation:
2
Location: New Forest
Car type: 27 Chummy
Many thanks for the suggestions.
I have read somewhere that if a spark tracks across an oily surface then a carbon track is left behind which can never be removed. Most dewatering products seem to lubricate as well so could they be oil based?
I think I will try the varnish first and see how that goes.
Many thanks.
Adrian.
Joined: Mar 2015 Posts: 5,445 Threads: 231
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Location: Scotchland
Does anyone know if these type of caps could be 3D printed?
Joined: Aug 2017 Posts: 142 Threads: 29
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Location: New Forest
Car type: 27 Chummy
Hello Ruairidh
The shape would not be a problem, but the dielectric strength of the printing filament might be a problem.
I once read an interesting article about a group trying to recreate distributor caps for the liberty engines. They tried several resins I believe without success.
Adrian.
Joined: Mar 2015 Posts: 5,445 Threads: 231
Reputation:
67
Location: Scotchland
That’s a shame, maybe one day soon...
Joined: Aug 2017 Posts: 926 Threads: 22
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Location: Near Cambridge, UK
Car type: 1928 tourer (mag type), short chassis Gould Ulster
It may be worth trying Donald Day. He does stock new BT-H caps, so possibly he has others as well. Sit down before he tells you the price!
Robert Leigh
Joined: Aug 2017 Posts: 41 Threads: 1
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I wonder...maybe it’s not possible (currently) to 3D print them, but what about using 3D printing to create cost effective tooling to allow them to be cast / injection moulded?
