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One constant problem in my restorations is painting old radiators. I’ve heard the theories from the painters I use, and frankly not one of them has managed to figure out how to get pain to stick for any length of time. It may hold for a year or two, but then comes the flaking and I get the phone calls. Anybody have a real solution? Is there a right way that I don’t know about?
SHG
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Replies
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Not sure if this is a real viable solution...I think it would be expensive.
Almost every radiator I've ever seen obviously lacked proper preparation before it was painted. Most recently evident by the paint colored dust bunnies in between the fins.
I have never attempted but there is ceramic coatings for auto manifolds are very high heat resistant finishes. Definate overkill but I bet you wouldnt get a callback.
*Don't know that I did anything special, but mine have stayed nice for >15 years. Cleaned good, primed with rustoleum, and spray-painted whatever color I wanted.
*As kid I ocassionally helped out in a family friend's auto body shop. Used to sand blast the radiators, wipe down with lacquer thinner, and spray with high temp engine paint. The color selection is a little limited, silver, black ....a few others .......don't think your clients would go for Chevy Tonawanda orange.
*Any good paint store or HD or wherever you buy from should have spray radiator paint. Usually black, silver, white or ivory. You may get lucky and find another color selection through special ordering, but I don't know as I haven't had the need. The paint itself I've not had problems with, it's usually surface prep that bugs me.
*Ch*vy Tonawanda? I thought they were using romantic names like Yukon, Denali, and the like. Oh well, Tonawanda's a nice place too, been there a couple of times..The radiators themselves don't get all that hot, do they? I mean, they mustn't get over 212 degrees (boiling temp of water). That being said, hi heat paint shud be more than sufficient. If you want superior, long-term adhesion take the thing to your local body shop, have them sandblast it (probly wouldn't fit in a glass bead cabinet) and prime it with self-etching primer, then paint it. You could probly choose any color you like at your local body shop including Tonawanda Orange, Wimbledon White, or Plum Crazy Purple for that matter. If you have a buncha rads to do it shudn't be that costly either. The only issue I wud have with painting with real live automotive paint is the ongoing smell. I for one am a bit sensitive to all the weird stuff they put in it, so you'd have to let them cure awhile before they'd completely stop stinking. But this would definitely be the best long-term solution.
*Nah,nah. You guys don't get it. In the houses I do, there are between 30 and 40 radiators. These are old houses. We bring 'em down bare, and the painters prime with rustoleum high heat primer and paint. And still.We're not talking about one radiator. We're talking truckloads here. And these are not houses that get painted Tonawanda orange (though I knew her and she was a fine young woman).SHG
*Okay, I think I get it now. Is Tonawanda Orange kind of like Yankee Rose or something?Seriously, if you are REALLY set on making the rads look good, and last, you can do this:Find a Redi-Strip location in your area. They hot (caustic) tank large metal items (car bodies, my truck, ship parts) then they drop them in an electrolysis tank to derust them, then they dunk them in a phosphate tank. This would seem to be ideal for high-end restoration of cast-iron rads (it would destroy aluminum and brass, though). This isn't your local engine shop. These guys dump forkliftfuls of stuff into their tanks at one time. Seems perfect for a truckload of radiators. You end up with phosphated clean metal with no rust whatsoever, noplace. Nooks crannies and all are completely clean. Then you can have them painted at, say, your local body or other such paint shop en masse with self-etching epoxy primer and whatever color you choose. You could (if you were so inclined) even go with a base coat-clear coat system. The nice part about hot-tanking the rads is all the crud from inside would be removed as well. Short of taking them to your local Ford (or Hyundai for that matter) plant this is probably the largest-scale option I can think of. If you can think of a better painting option (say a shipyard or something) great, but for old paint removal and derusting, Redi-Strip is the biggest place you can go. They also operate Redi-Blast, which does industrial sand/walnutshell/whatever blasting. But for a really proper job on the radiators, I'd recommend the chemical process. The only difficulty you'll run into is if the threaded portion of the radiator is quite corroded, you'll end up with pits in the threads after the derusting. But you'd probably have the rust with or without stripping, leading to leaks sooner or later. At least if you had them stripped and derusted properly you could weld any bad spots, which you couldn't do without hot tanking and derusting. Redi-Strip is a North America-wide chain. Take a sample rad down and see how it turns out. I don't think you'll be disappointed, my truck turned out beautiful.
*One more thing, you may wish to check out a paint system called Endura, which is probably the most durable paint in existence. Comes in very many colors, the gunmetal would look quite nice on a radiator. From my experience (however limited) with vintage auto restorations, it doesn't matter what you put on top if the paint doesn't stick to the metal. So the metal has to be absolutely clean and rust free (or it will bubble). There is no way to get this level of cleanliness without hot tanking, derusting and phosphating. Then, the self-etching primer (which is a 2-part epoxy, available in low or high build, Standox makes a very good one, and the PPG one isn't bad either, and both are tintable) will actually etch the metal for better adhesion. Then you can paint over it. If you don't use a good self-etching primer over clean metal, you might as well just wrap it in wax paper. It isn't gonna stick. Spray bombs are only good for cosmetics. Some of the 'better' ones, like Krylon, just contain powerful solvents designed to soften the paint underneath for better adhesion. Rust paints are designed to seal rust in so that oxidation takes longer, but it definitely doesn't stop. Rust stoppers like Coroless work for a bit longer, but still won't stick to a hundred years of grime (and probably nicotine). And the heat a radiator is subjected to compounds the problem by speeding up chemical reactions. Whatever you have will bubble sooner or later; clean metal will bubble the latest of all, and with proper care, not for 20-30 years or more. Think of it, you don't even need to use hi-heat paint. How hot do you think a car hood gets on a hundred-degree sunny day? No hotter than a household radiator, that's for sure. The other option is powder-coating. This will stick really well to good clean metal. And heat only helps it along. It is an electromagnetic process whereby the powder is charged one way and the metal the other. The particles are thereby attracted, and then baked at very high heat. You need clean metal for this, though, so Redi-Strip would still be a good option for you. Whew. That was a mouthful. But I hope it helps. Redi-Strip is your absolute best bet for a clean base you can paint, or powdercoat properly. And by the way I have nothing to do with those guys except being a happy customer.
*There's other stuff made by Eastwood, another by Bill Hirsch, which is exhaust manifold coating, in black or gunmetal or silver. But this stuff needs to get to exhaust manifold temperature to cure, smokes like Janis Joplin when it's curing. If it never gets that hot it'll just stink for 20 years. Good idea, but not an option in this case. Powdercoating would work well though, with proper surfacing.
*Why am I continuing to post to this article? Just can't stop thinking about it I guess.You said your painters use rustoleum primer then paint. Don't mean to patronize you, cuz you might know all this, but here goes:Paint comes in two kinds, one-part and two-part. One-part paint, like rustoleum, tremclad, krylon, or even your garden variety Interior Latex, is pigment suspended in solvent. You smear it on, the solvent (in most cases Volatile Organic Chemicals or VOC's) evaporates, and the pigment is left on. The dissolved pigment hardens when the solvent evaporates. So it's kind of like Saran Wrap.Two part paint is a resin, suspended in solvent, to which you add a hardener. While the chemical process is proceeding the rapidly hardening particles, which are suspended in a liquid emulsion (usually VOC), are applied onto the surface. The VOC evaporates and the resin and hardener react and create a new chemical coating. In most cases the resin and hardener contain agents which etch the surface for better adhesion (the mixture is somewhat acidic or basic until the chemical reaction is complete). Not to be presumptuous, but it seems to me your problem is that you're using one part paint, which doesn't etch. On top of that I don't know what you're doing to take the rads down to bare metal, but even with sandblasting there are pinprick-sized pits in the metal which are just immature rust bubbles. The other way to get the paint to stick to the metal is electrostatically, i.e. with powdercoating. But I've already mentioned this. Okay, I've finally said everything there is to say, I think. Sorry for being so long-winded.
*Okay, now I have to take this a little slower. Could you explain it again, starting with the part following your name on the first post. Truthfully, I follow, though paint is the one area where I've dutifully tried to know absolutely no more than absolutely necessary. I always figured that painters got that was from breathing fumes, and I don't look good in white pants anyway.I don't know that I can get anyone to pay for all this. They'll go for a good hand stripping and painting, but this will sound extreme and extremely expensive. But it's great info. Thanks.SHG
*Tonawanda is a (I am not going to say picturesque) city in Western New York, near Buffalo. If you really wanted an explanation. It could also be a cruel nickname for a very fat girl. Powder coating isn't expensive, can't cost you more than 40-50 bucks per rad. If you sandblast well and powder coat, the rust won't happen for a good 15 yearsx or more, imho.
*Chevy (GM) had an engine plant in Tonawanda ....believe its been closed. SHG, how are they bring them down bare? I don't believe scraping is good enough on cast iron.
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One constant problem in my restorations is painting old radiators. I've heard the theories from the painters I use, and frankly not one of them has managed to figure out how to get pain to stick for any length of time. It may hold for a year or two, but then comes the flaking and I get the phone calls. Anybody have a real solution? Is there a right way that I don't know about?
SHG