Don't know how advanced it is, but i figure the advanced guys would have the most knowledge on this.


Has any one had experience, good or bad, with coating your own headers. I have a compressor and sprayer, so doing it is no problem, but i want to do it right the first time.


Any help is appreciated.

Mike

 

I used to know the URL by heart, there is at least one member here who has done his own in black. He moved from Homestead and I could never remember the new URL.

If someone can't come up with it, I can dig for it later.

Basic problems I think are cleanliness of the header (sterility somewhat), since you need as much bonding as possible, just like any kind of paint. There is steel sterilizer that might be used, used for regular high temp paint and can be found at paint stores. You also of course need a rust free, and paint free surface to apply too.

 

http://members.***.net/gmarengo/


That's probably what you are talking about, and i think its a good guide, so i guess i'll follow that.

Thanks,

Mike

 

Yep, I dont hang around tech much but thats the only one I'm aware of as far as DIY on the site.

 

One of the advantages of a professionally applied cera-metallic coating is the application to BOTH inside and outside surfaces of the header tube. Aids significantly in retaining heat within the tube. I can't see any evidence in the link that he coated the inside of the tubes, but maybe I missed it. I was also a little surprised by his comment that a black coating was a better thermal barrier than a chrome-colored coating, and that sort of flies in the face of traditional heat transfer. Maybe its the structure of the coating and not the color that differentiates it, but I'd want to see more info before accepting that statement.

 

I've actually read that flat black is better for avoiding heat, but I dont know the truth in that, because I always thought black ABSORBED heat due to its color law of absorbing all colors of light yada yada, hmm.

I think the internal coating is wise as well, and it only runs you a couple hundred bucks to get it done professionally. Coating on the outside might not be much better than running header wrap, which will void most header warranties.

 

Jet-Hot's strongest coating (2000 degrees) is black in color...maybe he was refering to that?

 

The silver coating is aluminized of some sort isn't it? I know it melts at low temp but I thought it was aluminized coating, which is not a great heat conductor but doesn't hold it that well either.

 

yea, for some reason the good coatings are allblack. thats what I am coating the outside of my turbo headers with.

 

From talking to many coating companies, the reason that black is used in high temp (turbo) apps is because there is aluminum in the metallic coating, and will dull over time. Some shops will not even coat a turbo manifold with the metallic coating simply to avoid an issue when it does fade. We coated one for a honda with the metallic and it does have some fading at the flange. It simply looks flat now, instead of shiny. The rest of the piping is great though.

 

Without going back to my "thermo" books, and just from memory, black will absorb heat better, and black will emit heat better. For example, your household heating radiators would work better painted black than silver. But you want the header primaries to retain heat, so black wouldn't seem to be "good" for thermodynamic reasons.

I know several of the coating companies, like Jet Hot use a "black chrome" finish on their high temp (2000degF) coatings, but I would guess that this is more of an issue of the compounds they need to put into the coating to make it stand up to those kind of temperatures, than "black" performing better thermodynamically. And maybe a bit of the aesthetic approach too, to limit visibility of high temperature dulling or discoloration, as noted in a post above. I think "brain's" post confirms this.

As I recall, Swain has an intake manifold system the coats the underside of the manifold with a "silvery" reflective TBC to keep engine heat from entering the manifold, and coats the top of the manifold with a dull black "emitter" coat to promote loss of any heat that gets past the internal TBC.

 

With black being a better absorber and transmitter of heat, would it actually make a difference then to paint an aluminum radiator black?

Sorry that this is a little off topic, but this question has peaked my interest.

Jon

 

This 'trick' is used on brake calipers, dunno about radiators.

 

Swain tech's coatings on the headers are white and they don't coat the inside of the headers. Got to find the email they sent me on why.

Edit: cant find the email. Guess I'll have to do some research again.

 

Yes. Make sure it is a thin layered paint. Too thick, and the paint would act as "mini-insulation".