Powder Coating Temperature Limit

[Michael Oritt]

I'm considering powder coating the aluminum valve cover on the Climax engine in my Elva MK IV, and there a lot of different opinions online regarding the maximum temperature against which powder coating will stand up. I have not measured the actual temperature under race conditions, but assuming the valve cover does not get any hotter than the engine, I'd guess that 250 degrees would be a safe number.

Does anyone have input--based on experience rather than internet opinion?

 

[BigGreen]

Reply from my (Dutch) source;

The standard powder coating cannot withstand high temperatures above 120 (edit °C) degrees for a long time.
With the exception of Alesta® Heat Resistant that is heat resistant up to 550 °C, only available in black with a light structure.

 

[Michael Oritt]

BG--

I have seen some online sites saying 200F to be the upper limit and I wonder if you are saying 120C.
In any case I think I'll simply use engine paint which I am sure will work and also be less costly than PC.

 

[dougie]

Hello Micheal -
My business is architectural and industrial coatings, both liquid and powder. There are high temp powders that can handle 1500-2000 degrees. For what you're looking for, a high quality 2k urethane can withstand sustained temperatures of 300+ degrees. For small one-off projects like engine blocks/heads, I've had great success priming with this, > 2K AeroSpray High Temp Engine Primer Gray <
And then top coating with a good quality 2K acrylic polyurethane.

 

[BigGreen]

Yep °C

 

[Michael Oritt]

Dougie--

Thanks for the info and now that I have begun to consider lower tech applications I wonder if there is any advantage to the coatings yoiu specify over a good engine paint? The CC valve cover is an unpolished aluminum casting and I am not looking for high gloss so much as durability.

 

[Rob Glasgow]

I’ve always admired exhaust manifolds with porcelain finishes like the XK 150 Jags and wondered how durable they were. Seems like they would be prone to cracking. Maybe the are is similar to the ceramic coating I had applied to the exhaust manifolds on my BT7. That has held up well.

 

[Guido36]

I have a ceramic coated intake manifold and powder coated rocker covers on my Healey 100 nasty boy which has plenty of thermal load. Neither shows any ill effects. I have other high performance vehicles and race engines with powder coated engine components and have never had a heat related problem affect the powder coat….