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
Here is what I’m working with, it’s a bare long block, and I feel like whatever cleaning/prep method I use, I need to protect the internals and surfaces that I don’t want to get wet. So I wiped down every surface that I plan to tape with acetone and a clean cloth. I figured I’d tape it all off first and then clean it. I can’t even get the tape to stick- I’m using regular 3M blue painters tape. And it just won’t stick to any surface. I can’t even begin to imagine how you would clean this with dish soap and water without making a huge mess and getting water into places where you don’t want water. That’s the other reason I was thinking brake cleaner - for control to make sure it doesn’t get into the internals. Am I better off just****embling everything and then painting it? I thought it would be a cleaner/more pro look if I painted everything separate before****embly. I want to get this done since we’re moving into the cold/rainy season here very quickly. Thanks!
I have a 5 gallon bucket of lacquer thinner that I use to degrease everything I’m going to paint first. Sometimes takes a lot but that’s why I buy 5 gallons at a time. After the thinner comes the wax and grease remover. Uses up a lot of rags too. Spray can prime, spray can paint. Almost always use Rustoleum in one version or another. Usually turns out pretty good, some things have been in service for several years and are still acceptable-to me anyway. But all my stuff is not show car worthy, they’re just drivers. And hardly anybody anymore gets down on their hands and knees to look under a car or truck, mostly because we have to ask for help to get up.☹️.
Came here to say this about using a torch and watch the moisture leave the iron. The iron always has moisture on the surface unless you pull it out somehow. Like others have suggested, Dawn dishwashing soap. This has an advantage IMO because you can use hot water which will lift the soil more effectively and it is very cheap. It's also non toxic for those who are into that sort of thing.
I like to clean with a torch. That’s how we did it growing up. Ill also use a wax and grease remover with a scuff pad. Then epoxy and automotive paint. Torch it and spray it Done
A method I've heard of other guys doing is mock up everything without gaskets, spray it all, then disassemble and reassemble with all the gaskets. I just tape stuff off and spray it separately, but I'm doing one here and there.
I guess the last four I’ve done for myself have been clean Baer metal so it’s automotive epoxy primer and single stage urethane paint. My 289s and the race 440 get a semi gloss black, the mild 440 gets New Kubota Orange. All the blocks do git hit with 80 grit after they are a deburred.
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