I suspect that this has most likely been covered before, but can anyone suggest a suitable make of paint for painting a crankcase internally? ie. it needs to be oil and heat resistant. I gratefully await any suggections.
Thanks, Paul.
Principle 1. First do no harm.
I would strongly resist any temptation to paint the internals of any engine...It won't be seen....And the next owner will curse you from his/er grave.... If you must just get it beadblasted(protecting any bearing sufaces of course...
Degrease thoroughly. Sweat the bit in the oven to force out some of the remaing oil. About gas mark 4...Cool gently on a bed of kitchen towels.. Soak in a suitable sovent.. Repeat as necessary until the bare metal seems to suck oil from your fingers... Remember that metals are porous..Then apply Hammerite...which can be removed later with xylene (and a wire brush) .. sometimes maybe possibly..
Do this more than once.
And never, ever try to sell me the result. Painted internals are just plain wrong and a source of future failures..Please stamp an extra three asteisks after the engine number to warn others..
Of course, you may be prepping this as a museum piece with cutaways etc..in which case try contacting the museum of science and industry in newcastle....
(when I was young I used to derive enjoyment there .. from rolling a torpedo across the room)
And, of course, there is the "Turbinia"
(the Araldite Kid)
? Where did you acquire this opinion? It is certainly at variance with countless engine manufacturers" practice.
Tom
Engine makers are not neccesarily right... I still feel that painting internals is dead wrong...And a potential source of future failure.. Ok, I humbly admit that almost all my experience is with motorcycle engines, from torsion spring, hairsping, desmodromic and many poxy two strokes.. (and my ancient Avenger...)...
But...
On a positive note, and remembering an ancient Honda crank from a CB500T I seem to remember that the big wheely things on the sides were painted green on the edges. I think it was called a double underhand crumptshaft... :-) And it had high compression mist irons too...
I'd assumed this was some sort of enamel - Thing to do Is to get a tester can of the colour you want, spray it onto clean steel. Let it dry well ( bung it in the oven..:-) ) Then soak it in petrol... If it goes soggy - not good..
I have found Hammerite paints to be very resistant to petrol/solvents (including a brief interlude with nitromethanol)
And again, before applying a paint/primer it really is important to sweat out any oil in the metal.. You'd be surprised at how much oil can be held in steel -- I've had some success with cycling fairy liquid, white spirit....
Generally though, the only things I'm comforable with in the engine apart from oil and componets are blue hylomar, kawasaki bond( grossly underated imho) and loctite... I do undestand why you would want to paint bits that noone will ever see-- bit of a paranoid completist myself)
Hey, it's your engine.. Enjoy!
You may be wrong?
But engine manufacturer's are painting fresh castings that have never seen a bit oil. A cast component that has seen oil, is near impossible to get fully clean to get paint to stick well. Any oil that gets trapped behind a layer of paint, will most likely cause the paint to bubble and peal off, which is not a good thing inside an engine.
If you haven't already got something in there, then I wouldn't do anything.
If you have existing red/brown primer then you might want to try and find out what was used originally, probably an oil-based paint, rather than put something on top that will lift off the old paint.
Most of this was put on before the machining was carried out, so was probably applied to the raw castings.
Peter
-- Peter A Forbes Prepair Ltd, Rushden, UK snipped-for-privacy@easynet.co.uk
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