Picked up a fresh engine from the rebuilder last week. Gonna prime and paint it before****embly, but it’s covered in a coat of oily residue. What do you recommend to clean it up and prep for paint? My normal go to, and maybe this is why all of my rattle can jobs turn out so poorly, is to spray it down with brakleen. I always used brakleen to clean parts prior to paint, since it dries so fast and doesn’t leave any residue, and no need to use a cloth so no chance of fibers left from a rag. Is brakleen not a good cleaner to use for paint prep? I used it to clean the valve cover and timing cover prior to priming, but the primer dried with a fuzzy texture to it that I now need to sand down. I did several light coats about two minutes apart. So what is the best way to clean to oil residue off and prop an engine for paint? Also would love to hear some pointers on rattle can painting in general, since everything I spray comes out poorly in my opinion.
It is a rust remover. You could spray the engine with a solvent first. But I’d definitely use a rust remover before priming. I’ve had good luck with Duplicolor engine paint and the matching primer.
I had a set of heads two years ago with the same issue, they came back in bare metal and oily. I cleaned them with brake clean, wiped them with wax and grease remover and a lint-free cloth, and once they were dry I taped them all up and sprayed them with Dupli-Color ceramic engine paint. I got a nice smooth, shiny finish and it looks as great today as it did then. For spray can painting: When you think the surface is clean and dry prior to painting, go over it one more time. Keep your distance from the surface consistent Start and stop your spray off of the part Start with very light coats, getting heavier as you progress Don't spray in direct sun, wind, etc. Some guys swear by preheating the paint can in water or carefully with a heat gun (depending on the time of year and your ambient temp), it can help the paint flow better. I've never done it. On my cylinder heads I think I had 4 or 5 coats total. I didn't prime them at all.
My engine was painted with spray on brake caliper paint from the auto parts store. Prime and let dry with brake clean. Spray the bare iron engine with caliper paint. Long lasting, looks good.
During winter I will heat the rattle can and use a propane torch to heat the parts I am painting. Not hot, but warm enough that it bakes that first coat on. It works. I clean blocks with reducer, just like any car before I paint it. I use epoxy primer, automotive base/clear after sanding down the casting so I have a nice smooth finish. I also added metal flake to the flathead before I shot it in hardened clear. I use paint guns but you can have hardened enamel put in 2K rattle cans at any reputable paint store, including clear.
For rattle cans I use direct to metal paint. No primer. I found thicker paint layers are more prone to cracking and flaking. As the surface is slightly porous so I use kerosene to draw out any contaminants then brake cleaner or acetone as a final degrease.
If it’s a bare block or head I degrease with brake cleaner and use a propane torch to burn off anything else (might not be an option in your case). I like Rustoleum industrial paint, it’s not affected as much by a little bits of oil left behind unlike a body paint and it seems to last well on an engine, no primer either.
I use this before painting many items. Hot water, plenty of rinsing, blow dry with air pressure and then let it sit for a day or two. Maintain 60-65’ during painting/drying
I use a propane bottle to carefully burn off any oil residue, don't get too hot near gaskets and seals , wipe down with lacquer thinner and paint
I've always washed the exterior of blocks with dishwashing soap diluted in water just like you'd do the dishes. Then blow it dry with an air hose, and mask off any machined surfaces before painting. As soon as the paint dries I remove masking and wipe down the machined surfaces with an oiled rag and then****emble the engine. Never had any issues with engine enamel in rattle cans ever coming off doing it this way.
Just used brake cleaner and Duplicolor engine paint topcoat. Block had a slight coat of surface rust as it had sat for over a year (inside my house) with no paint. No primer. Turned out very good. Will see how well it holds up though in service.
After whatever cleaning method you go with, use a propane bottle and heat the surface. You will be able watch and see the all moister and contaminant being pulled from the metal.
And get yourself a few of these they are a game changer for spray bomb painting,got mine at Ace support my local hardware store plus I'm friends with the owner
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