Inspired by NYDESMO.com I've resprayed my heads using etch primer and then satin black, then dremel'd the fins edges to achieve the required finish. This works best on the lower cylinder head half which is the original powder coat finish, but the resprayed upper is trickier as some of the paint around the edges has flaked off in the process. Any ideas how I can overcome this?
I've been thinking about this. I think I will finish the polishing, then mask the polished edges and respray where the paint has flaked off. Then lacquer to prevent corrosion of the edges (as suggested to me on a previous post) and hopefully 'seal' everything. It probably won't be as durable as powder coat but the cost for that would be much higher.
I've never heard of people powder coating the barrels or heads - only the valve covers and side casings. Powdercoating requires curing for 10mins at at least 200c and although i know a lot of heat gets generated when running, I'm not sure it would do either any good unless you wanted to shift valve seats and bore liners etc so bare castings only. Not sure of the thermal efficiency compared to VHT paints either? Yours looks really good. The ultimate finish would be ceramic coating I think. My project engine has been soda blasted and and I'm leaving it bare - just a good dousing in ACF50 beofre she goes on the road. Ceramic coating is thwe ultimate I think.
Etch primer does not stand up to heat very well unfortunately so high heat can cause flaking at a later stage. Polishing the edges might be easier if you do it when the paint is still soft and is less likely to flake or tear, or you could try scraping it when soft with a plastic grouting tool. This makes a good strong scraper for soft surfaces and does not dig in to the metal. I use Hammerite satin black for painting cases and that stands up to wear and tear very well, although it obviously does not get as much heat transference as a cylinder would. If cured correctly though it is one of the best finishes I have tried and it is not necessary to use a primer.
i would say paint and then use a fine sand paper to sand through edges without chipping paint.. maybe 180 0r 220 grit on a block
Thanks for the tips and advice, for info I used Auto Glym Satin Black but never thought about Hammerite although I see that comes in aerosol spray form too.
used bbq paint on exhausts with good results could get a nice satin finish one a few years ago looked good and lasted well
