Do you think i could paint strip and soda / vapour blast with the removed engine complete, or is it going to involve a full strip down to component parts? Although i can block / tape up all the points of entry, i wasnt sure how the seals and gaskets would stand up to the process if still assembled...
The sandcast casings aren’t painted. But I don’t know if they are treated in some way to stop oxidisation.
Mine has the same kind of staining mate, I've tried numerous "cleaners" but nothing touches it. Be interested to see how you progress on this.
I wouldn't use any process like soda blasting or vapour on a complete engine . I ask my vapour blaster the same question and he said no way to ensure blasting material won't get in . It will destroy engine in no time at all . There was an engine for sale on ebay , I think a multistrada that expired this way and I think I sold for less than £350 .
I am sure the chemical reaction went through the full thickness of the existing paint layer, therefore vapour blasting would not help removing the staining. Sand with 380-600 grit wet paper the existing paint. I see no point in completely removing existing paint, you just need to open the pores, so the new paint can stick to the existing one. One thing is very important ! never leave more than 24hours between sanding and applying the new paint layer. Most ideally sanding and spraying should be done the same day.
