After many years of using most every kind of automotive paint - from high-end epoxy's to the lowly spray can (or spray bomb - as it's known in the trade), there's one thing that I know for fact: though many paints can be used for many things, some applications call for very specific paint formulations. And the more often you use the right paint type for the job, the better and longer lasting the result. It's not that you can't use a paint "off-label" (for something other than what it is described for) and I'm sure we all have done it often, but you really should try to be sure that whatever you are using it for, it is going to perform over and above your needs to survive the actual conditions it will endure. Sure, many rods sit in climate controlled garages - but many more do not. Using products meant to survive various temps and chemical assaults will make you happy you put the effort in. Whether you use Krylon, Tremclad or a bargain brand, you're not getting much with paint in a spray can. While it's true that paints in spray bombs have been greatly improved upon over the years, such as the advent of "high-temp" coatings, there's still no substitute for activated 2-part paints, and, to a lesser extent, for some of the true specialty paints marketed today, such as Dupli-Colors VHT paints. The plain truth? Two-part activated or "hardened" paints are by far the best, most durable and longest-lasting products you can use and just cannot be stored in a spray bomb - unless of course some high-tech design is incorporated to keep the activator separate until use - which is rare and expensive! After much research and many trials in my own shop, I've found paints that work incredibly well in specific situations and tend to stick to these findings. One such paint that incorporates these attributes, are the Activated High Temp Engine and Caliper Paints marketed by a few companies like Eastwood and Dupli-color, as well as the use of catalyzed auto body paint that you can source at your local auto body supply store. These 2-part-ceramic-containing paints employ the properties you need when you're subjecting them to the seriously harsh conditions of an engine bay, or the heat produced in braking. In these applications, parts are subjected to high heat, various solvents, rapid heating and cooling cycles and a virtual sand-blasting from road grit and dirt. A brief look into the scientific properties that allow these paints to endure and perform as they do includes the utilization of ceramic particle nanotechnology, added alkyd esters contained within them and the hardening properties of the activators required. These properties allow these paints to: - withstand temperatures up to 650F. Spray can paints generally state they will withstand temperatures of 350-400F, which occurs fairly quickly even in a stock engine bay. - be highly resistant to most chemicals, most notably Gasoline and Diesel fuels - many can be brushed or sprayed on - go a long way: one quart covers approx. 40 square feet - some, such as Eastwood's Ceramic Engine Paint, can be used as a single stage paint, but for maximum durability and gloss, I always Eastwood's activator (21854Z) Recently, I swapped out a flathead V8 from a Mercury Truck, due to a serious flaw in the block. The swap engine had likely been painted with a "run-of-the-mill" paint years back. It was peeling near the manifolds, had wrinkled where oil or gas had leaked and just didn't have any shine left, making for a dull, drab engine bay. The first thing I did is strip the engine down to the basic long block. Then, we took that down to bare metal, first with wire wheels, then with lacquer thinner, making sure to strip all the old paint from the many nooks, crannies and dead-end holes. Once all the old paint was gone, the block and parts were thoroughly wiped with a wax, oil and grease remover, in this case Eastwood's PRE solvent. Once stripped, cleaned and masked, I put 2 wet coats of etch primer over the bare metal and let it set up for an hour. As with any primer or paint, there's a re-coat window for etch primer, but be sure to read the tech sheet on whatever product you use. The re-coat window is the span of time available to spray your next coat - or product - before which the solvents haven't sufficiently flashed off and after-which the paint becomes too dry to allow molecular bonding to subsequent coats. If you wait until the next day - and past the recoat window - you'll have to scuff the primer so the top coat will adhere. The next stage was the application of Eastwood's High Temp Ceramic Paint. This product can apparently be brushed on right out of the can (as a single-stage paint), though I would always use it in a two-part format by mixing it with the activator available. According to Eastwood - and as per Paint Chemistry 101 - using it with an activator confers much more gloss and added durability to the product. I sprayed the paint with my detail gun, at a pressure of 25psi, putting on one light coat, waiting until dry to the touch, then spraying 3 medium-wet coats for full hide and gloss. The painted engine was left to cure for 24 hours, then un-masked and re-assembled. I think you'll agree it looks great - and with the durability seen with Eastwood's High Temp Engine paint - I can be confident I can WOW people whenever I open the hood - for years to come!
Very informative, but I see a flaw...I have yet to be able to find a high temp primer, what keeps it from peeling?
I have found - over many engines - that etch primers are immune to heat. No. I sell drugs (pharma rep ), but I have a "serious-hobby" shop I call E-tek Restorations and like to review products and write them up on my site & blog.
thank you for sharing your experiences with several different companies rust stoppers and paints , good information for when we need to use these types of products , your like a HAMB version of consumer reports , keep up the good work
Not true. Hirsh spray bomb engine paint is good to much higher than that. I've never had it peel from heat. Super nice gloss flow out right out of the can. http://www.hirschauto.com/departments.asp?dept=2 http://www.hirschauto.com/prodinfo.asp?number=PRIM HT
The Hirsch high-heat paint is rated to 700F. I'm not saying it's not a good product - it sounds like it's one of the best heat-rated spray can paints out there, but I've never seen it for sale here. Most paints in spray cans, even paints listed as high-temperature paints, are rated at less than that: Dupli-color's VHT (very High Heat) paint is rated to 500F Temclad's High-Heat Rust Paint is rated at 650F Rust-oleum Engine Enamel is rated at 500F Cheers!
For primer on engines I like Rust Destroyer which is heat resistant to 800˚F - I get it at Home Depot but not all of them carry it any more. I have been using it for years and never any issues. It likes a few days to cure and then it's as tough as nails....
speaking of off the shelf, the krylon fusion paint also sticks very well to bare aluminum, it's not just for plastic, the semigloss black looks like a lot of factory black stuff
Hmmm - that's another product I've never seen North of the border. At 800F I would definitely use that under the Ceramic-containing paints. I may have to do a follow up study with brands available in the US!
Canadian Tire used to sell it but I haven't looked for a while so not sure anymore. They seem to have moved everything over to either 3M or Dupli Color
The makers of Rust Destroyer contacted me this week and will be sending me some product to try on my '27 Rod build. I'll give it a full try and post up the results when I'm done.
Nads and I recently painted his Buick Nailhead project with Eastwoods single stage red. Came in a quart can. engine was etched primed, directly after coming home from machine shop and thurough soap and water scrub. Ace Hardware been selling a good etch primer as of late. Last few engines I built, have made it a habit to paint engine before any assembly oils get a chance to penetrate cast iron. In this instace, had to wait till engine was all together, before I could paint. Left intake off, so we could do a complete job on valley cover. It did take quite awhile to dry(24hrs??) But once done, was shiny and hard as nails. He did not thin the paint at all. Overall very happy with product and will never spray bomb another engine. Thanks for the good info. JT
Eastwood says it's ceramic engine paint can be directly applied without primer. That is the way we applied it to my 283. We will see.
It would be interesting to find out just what manufacturer is doing the private labeling for Eastwood , since they're a mailorder company .
Why I painted my 283 with can paint... I have painted two engines with BASF catalyzed enamel....did they last 8 years and 12 years...yes...looked as good as the day I painted them the day I sold them. Here is why can paint....My house has a drive in basement...after driving both vehicles and pulling in the garage...you could really smell the paint real strong...so stong at times I had to wear a paint mask to work in the basement....the smell was still there the next day...not as strong...but still there. My corvette engine was painted in 84 when the engine was rebuilt...rattle can paint...lasted a long time...many years...never a paint super strong paint smell in the basement....I am sure some ill effects have occurred with me from the two catalyzed painted engines. A detached garage would change my opinion of course.
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