Leaky distributor cap

[andrew34ruby]

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.

Any varnish type product is likely to cause problems. After a few years it is likely to slightly crack, peal, etc. And it's then difficult to remove the 'varnish'. Holts wet-start used to do this, it was a very temporary fix. Holts damp-start was an oily water repellant and never gave problems. Thirty-odd years ago I used WD40 and Duck oil on thousands of old distributor caps with long lasting success.

If you can see a carbon track, just sandpaper it away, then spray.