I tried doing a search for engine paint (no quote marks because they don't seem to work) and I looked through the first 6 pages and came up empty. Actually when I tried to hit the back button it told me it couldn't find anything matching my search criteria (!).........

but I have a freshly machined (unassembled) engine at home now and the hot tank took everything off again.

What brands of paint are recommended for primer and for high temperature paint?

I have tried por-15 (not the engine specific paint) before only to have it peel off after a year.

So what does everyone recommend?

Plasti-Kote and DupliColor make engine paint. I've used both with acceptable success. Don't like Mopar Performance's engine paint. VHT makes good stuff. I've had excellent results with NAPA's farm equipment spray paint, colour = "International Harvester (IH) Red", made by Martin-Senour, as an excellent match for the '60-'68 engine red. Surprised you had poor results with POR15, which has a very good reputation. Are you sure you did the prepwork exactly to instructions?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I followed the instructions, did the metal-ready thing, everything I thought I had done right. Maybe I had missed something, its been quite a few years.

what did you primer your engine with prior to final coating?

I used no primer. I cleaned the metal extremely thoroughly, used a wash solvent the name of which escapes me at the moment (PreCleano?) made by an auto paint company and specifically intended for cleaning-down metal to remove all surface contaminants prior to painting, and set about applying the paint in a series of thin coats, which I allowed to "flash off" (partially dry) before each new coat.

The one time I tried using primer under the engine paint, the result sucked.

The factory didn't use any primer, either.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

no primer? huh......I figured the factory didn't use it since they had a pristine unit to start with, but I didn't know you could get away with that 30 years afterwards. I suppose it depends on the amount of prep and quality of paint. Now that I think of it I don't think any of the engine paint labels I have read actually said anything about a primer!

I am leaning towards using the VHT because I found a color that will match the car and its readily available here.

I do have some surface rust I plan to scrub the hell out of (wire brush), and plan on taking my time with it.

'course, gotta put it all back together first.

Hello,

I have used four of the POR products and have had no trouble. POR-15 is not for high temp so that is likely why it came off for you. I tested the high temp manifold paint on a broken manifold by applying the gray one and hitting it with an acetylene torch until passing from red to white hot. Upon cooldown, just fine so I used it on the real thing...just fine. I have also used it on brake backing plates and drums and on brackets used on the engine itself. I used Plastikote on the block and valve cover and pan. POR recommends you degrease with 'Marine Clean" then come back with "Metal Ready" and let em dry. I used both, AFTER scraping and heavy spraying with Auto Zones Valucraft Brake Cleaner...the real thing. I dried out the POR product treated steel on all parts and of frame by warming with an acetylene torch or propane torch. Literally, water ran from the steel...I did this because years ago as a welder I had to learn to get the water out of the steel before running certain beads. The POR treatments really atttack the steel while adding phosphate, and I could see how persons not having dried the metal would have trapped water under the coating.

rock
'64d100

Water out of steel...? Fascinating. I've played torches on steel and seen the water run, too, but I always understood it to be the copious water vapour produced by combustion condensing on the cold steel. Once no more mist or droplets would form, the steel was warm enough not to condense the combustion moisture.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hi Dan,

I am a physical chemist who specialized in iron oxides Iron interested me partly because iron is an element that goes through at least distinct changes..you can see it in soil, too. Iron goes from an electron configuration of +3 to +2 to +1 to zero, as it adds oxygen from water molecules. (Remember high school..LEO the Lion says GER...Loss of electrons is oxidation, gain of electrons is reduction?. In southern red clay soils and in rust, the iron is oxidized...no water. If you add a reducing agent as in the POR products, or add molecular water (from the air or groundwater) you can watch the red color in rust and in red soils go from red to yellow to black and the material is adding water to itself! That is a big part of why wet soils are black, besides the fact they are cooler and thus retain organic matter longer) and why iron and steel under water go black. Steel and iron both take up molecular water from that in the air after being heated and "dried" then cooling down. As the surface of say, a manifold, goes through repeated cycles of this some parts are highly dry (oxidized) and some aren't, thus you rarely get bright red manifold rust, but the intensity of the heating and the powder structure of the iron combine to make a powdery brown (+2) rust. Condensation on steel surface occurs because of the vapor pressure difference between water vapor inside the steel's structure and that in the air...water literally can't run into the steel so condenses on the surface. But with POR's reducing compound water going in is enhanced because some other ions are also being exchanged, I could mix up a more potent soup, but "Metal Ready" phosphoric acid is pretty darn good and much safer than the more potent soups.

So what? Well knowing the secret life of metals helps me paint, weld and play with em and be able to predict what might happen to my old slant parts! It is why I use stainless, bolts, washers, nuts and a good antiseize on connections.
rock
'64d100

Fascinating! Thanks for the lesson. Keep it comin'.

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Too many people who were born on third base actually believe they've hit a triple.

Actually, thats not what I used on the engine. I used straight VHT on the block a few years back and the hot tank took it out recently when it was machined (I fully expected that to happen, so it wasn't a big deal). I was just looking to see what others had used recently.

I had however used POR-15 on two items, the upper control arms and on my neon's driver side fender lip over the tire. both items peeled off after awhile, the fender lasted about six months and the control arm on the duster about a year.

I do remember using "metal-ready", although as I said earlier it has been a few years now (about five) and I can't remember exactly what steps I took.
I performed vacuum forming of various plastics for years before I got into CNC machining, and we normally had to heat up our aluminium molds (forms) with a large propane torch to get it up to a useable forming temperature, and also to rid them of moisture that effected the quality of the plastic parts. when the mold was heated, it would sweat like mad and had to be sopped up with a rag. if you tried to just burn off the water it would carbonize and leave garbage on the parts.

I also use DupliColor, Chrysler Industrial Red, and I don't prime. I wash everything with a good grease cleaner and water, then laquer thinner. Just before painting, I use a mild phosphoric acid metal prep. The results have been good.

now the fun part is balancing those crazy redox reactions (i'm one of about three people in my high school AP Chemistry class that can do it- to a certain level of complexity)....

never thought that stuff would ever come into a real life situation

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My Dart
GO VOLS!
It's not rocket science, we're just splitting atoms.

Eeyargh. I remember one thing about high school chemistry: Early in the year, the teacher brough in a 1-litre beaker with a stuffed mole inside. He used it to explain molarity: One mole in 1000 ml = one molar (I hope I got that right). He then removed the mole from the beaker, grabbed its head and its tail and yanked them apart, revealing the mole to have been held together with Velcro. He crammed the head part back in the beaker and said "There. Now it's one-half molar."

As far as balancing redox equations, I might be able to do it if I'd applied myself harder in maths and chemistry classes.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hm, I've heard about phosphoric acid for years, but never how to find it. Can you offer a suggestion here?

What might be the best way to treat a door with rust in the bottom? Apparently they hever had drain holes or the holes were stopped up. It is so rusted that the skin is starting to separate from the frame at the bottom - but not a lot through to the outside.

Theoretically one could use Bondo on it, but at the very least the heavy rust needs to be taken out and there's no way to get at it with power tools. A local suggested burning it out with a torch, and I'm not very excited about doing that. I'm hoping there is something I can squirt in there to do the job. Is this Metal Ready the thing?

From what I can see there must be different kinds of Metal Ready, but the sites I see seem to have more hype than information. Products I've had experience with require you to sand down the rust to almost nothing before application. Any suggestions appreciated.

He, erm, just gave you everything you need to find a convenient supply. Get on Google and search "metal ready" phosphoric , and you'll get numerous results. If you only need a little, the bright pink "Naval Jelly" rust remover from Duro, available at your local hardware store, is also a Phosphoric acid preparation.
Paint hides all kinds of corruption. if you've got rust severe enough that the skin has begun separating from the frame, it's likely that once the paint's removed and the rust removed, there'll be considerably more rot than is presently apparent.
Well...no. You can't de-rust metal that is no longer there! You're right to reject that silly "burn it out with a torch" idea; that's one of those things that usually starts with "Hey, one of y'all hold my beer, and y'all watch this!" and ends with ambulances and fire trucks.

For areas where the structural integrity hasn't been compromised (no separation, no missing metal, just rusty metal), a rust converter might be more appropriate. Do a google search on "rust converter" and you'll find lots of information.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.