Okay…so I’m doing some things to dress up the engine of my '70 E-Type OTS. I had the exhaust manifolds coated with “Ceramachrome”, supposedly it will never discolor, peel etc. Got aluminum cam covers, which really made an improvement over the ugly stock ones. Then, had my mechanic and his painter painted the cylinder head. I showed the painter a sheet of what I wanted, called “Oldsmobile Gold”…he stated: I know EXACTLY what you want! Well, he had NAPA do a custom mix, and what I got was “Warbird Yellow” with some tinge of green and gold metallic. While its not exactly what I wanted it’s something I can live with. The car is a driver, never to be judged under the bonnet. Now, here’s the dilemma…NAPA loaded the paint into an aerosol can that has a hardener that is activated by a plunger at the bottom of the can. It’s been 8 weeks now, and the paint is tacky to the touch, especially if you touch it when the engine is up to operating temps. So much so, it will leave fingerprints, and a microfiber cloth will “drag” as you pass it over, and will actually pick up some paint. It appears that I have no alternative but to redo it. So…(not knowing anything about paint) is this a pain in the ass to remove and redo? Should the aluminum cam covers be removed, or do you think they can mask around them?
I reached out to NAPA and was totally ignored. Upon consulting with the paint can manufacturer, he consulted with his experts and the general consensus was that a “2K” paint was not indicated for high temp applications. So, what to do? Is this a “strip” off all the existing paint? Can the existing paint be sealed and painted over? I have my triple SU carbs and intake manifold ready to be installed, which will be the final touches and give me my major “bling” moment. Boys and their toys!!
Did a quick Google and polyurethane actually starts to melt at shockingly low temperature. I assume it emits not so great to breath fumes also like most burning plastic. I can’t believe a painter was involved in that decision. Did he know you intended to actually drive the car?
It’s going to need to be fully removed again and carefully stripped and repainted with high temp paint like VHT. Not fun. Not sure what the best stripping method would be but I don’t think it’s sand blasting.
paint does not appear proper to my eye on computer. in my experience it will do what it wants to on startup and may cure with use and heat. probably very difficult to remove now. will not affect bling moment or value. j
After 8 weeks and several heat cycles, if it hasn’t hardened by now I doubt it ever will. Since it gets soft after running, I believe Erica’s idea is the correct one as is the advice of the paint maker and the paint is softening after being subjected to heat. A high-temperature paint is what is needed here.
I’d have to think, to do a quality job, the head would have to come off. If you want it to look really neat, pulling the head might take less time than painting around all the bolts and items with the head in place.
I’ve had very good luck with 2K primers, color and clear coats on engines and radiators. Applied with spray equipment with proper hardeners. Not good for high temperature like exhaust manifold. Engines block and cylinder head not really that hot with coolant running at 220F. A black car sitting in hot sun will be almost as hot. Eastwood also sells the rattle cans with built in hardeners. Something must have happened with the can that didn’t mix in the hardener. You can buy a cheap paint gun at harbor freight and mix you own paint. Use it two or three times and get your money back.
I sprayed mine with sng head paint. Its been on 3000 miles looks great . taped the nuts and cam covers and used paper to cover all around. Sprayed in very thin coats to keep it from running. I agree your paint is not going to set up
I just wonder if the hardener wasn’t mixed sufficiently prior to application?
Whichever, it sounds like you need to mask off the cam covers and seal the spark plug holes and strip the paint off and re-apply a more suitable paint.
I just measured my 4.2 S1 head temps after a 20 mile drive. It’s about 200°F in the valley between the cams, ~180°F on the intake side. Can’t get an accurate measure of the exhaust side of course - manifold temps were ~550°F.
If anything though, if it were a hardener problem the issue should be getting better and better if the engine is being run regularly. The exhaust heat would act as a kind of baking oven to supply the energy to link the paint molecules. A cheap normal enamel will harden when baked.
I’d expect the exhaust side of the head at least to show some sign of curing. If not, it probably is that the paint can’t take the heat and reverts to a plastic state when heated.
It may not. Some hardeners need to be in a pretty precise stoichiometric ratio, others, difference in mix ratio like you say simply changes the reaction time. No matter, looks like you are going to have to strip and redo, or get your painter to stand by his work.
I know someone here can as they had told me some time back, but I’m thinking it was at a build date of late ‘66, them being shipped as ‘67s. Look at xkedata.com and find the SN close to yours to find an approximate build date, if you haven’t gotten a Heritage Certificate
JCNA indicates they have no evidence that any cars titled as a ‘67 were gold. Unfortunately all that seems to do is suggest production in the latter half of ‘66 or later.
The two-part ratle cans are pretty specific with their instructions.
You have to be very careful to shake the can at the proper intervals.
My guess is that for whatever reason, it wasn’t mixed properly.
The stuff is toxic, and I wouldn’t be breathing near it if it’s still tacky and hot.
And I’m no chemist, but I’d venture that any removal technique is also something you wouldn’t want to breathe. If it were mine, I’d just bite the bullet, pull the head off, and start over.
Your car would have originally had a unpainted head (raw aluminium) so why not strip the paint off in situ and leave it bare. Only need to take off the cam covers and mask up.
