Hi!
Maybe this help someone.
Had my cars to get a few weeks away cause of registry. Yesterday i was getting my car back. What a hazzle - On each side of the pipes 2 big black plastic burnes from a plastic trouser on the section with the 4 pipes
.
and at the rear section a burn from a plastic bag. Have tried a lot of things: petroleum, thinner, terpentine, alcohol, polish...
But had no chance to get it of. Tried it with hot pipes...with plastic knives, wood, ice...everything i tried did not work.
Now i have tried it with a soldering lamp...was taking the hottest part of the flame directly on the creamic coat and what a surprise with a wet kitchen cloth you can rub most of it of - polishing - soldering lamp again - polsihing.... The flame is a lot hotter as the pipes when hot from driving. But the ceramic coat resists. Of course its no fun and a lot of work but after 3 hours the pipes looks like new. (and my hands are burned)
