Has anyone ever powder coated aluminum cylinder heads and if so how was the success? I am thinking about it, but the local rebuild shop said he would be concerned about heating the heads to 400 degrees and ending up with a possible warping issue. What do you think? Would you try it or not risk it?

 

 

Jonn,
Great idea!!! I've never heard of it being done before, so I would be interested in finding out how it works. Make sure you post the results here on the Forum so that EVERYONE knows how it pans out. Be a pioneer!! What could go wrong????
Don't let the fact that no-one else has done it before put you off. This great country you live in was founded by men who bit the bullet and went boldly where no man has gone before. (Hang on, I have to take the tablets.) Keep us posted.

Regards from Down Under

aussiejohn

 

 

If you use high temp resistant powdercoating it will work, headers can be powdercoated and a company here also powdercoats entire engine blocks (expensive w/ all the masking work to be done but really nice)

 

I have a friend with a 468 Pontiac in a 66 GTO with powder coated Edelbrock Aluminum heads. They look great after two years. Not even any discoloration on the exhaust part trhjat mates to the headers. His whole engine is powder coated and really looks great.

 

Just make sure that you clean the heads thoroughly after they are done to remove any of the powder coating residue inside the runners, etc.

 

don't let the seat's fall out of the heads if them have them (insert's)

 

As DVG said....

The powder coating won't stick where the surface has not been prepped. Well,
maybe I should say, won't stick for a long time. It will fall off when you least
expect or want it to fall off

 

Normal powder coating starts with a phosphate bath, then the part is hung on a charged chain, the powder goes everywhere so any place you don't want it must be masked off. The chain then travels through an oven at about 400 degree F where the powder melts onto the head.
I feel this could be hard on the head, what if a seat or guide dropped out?? So little of the head shows why not just spray paint???

 

The chain is the ground, the gun charges the particles.

Why would you need a phosphate bath? The zinc & iron phosphate baths are used to give better adhesion (phosphate deposits and a little etching) but it will only do that on ferrous metals, not aluminium.

Phosphating is usually done when powdercoating galvanized materials, this to provide a good surface for adhesion. However, it won't work on galvanized amterials that have been passivated. Zinc phosphate will give the best result, iron phosphates a little poorer but still good enough for normal quality surface finish. Indoor applications will do fine w/ an iron phosphate treatment, outdoors would benefit from zinc phosphate.

Because aluminium forms oxides really quickly you will need to remove that, so you need to clean it properly otherwise you could get chalking problems over time which will ruin the finish (bubbles, flaking and loss of adhesion). You would have to prep the aluminium with something like hydrochloric acid or a fluoride treatment (HF, a strong acid!) or sandblasting (I have done that on some manifolds and other parts) Untreated (not etched or roughed up any other way) aluminium gives poor adhesion.

 

I am just stating what a production powder coating line does. This is standard procedure. They use the posphate bath to degrease even though the part is new.
My son runs one of these lines and this is his setup.

 

Thank you everyone for your imput. With all of your help, I have decided to powder coat them. They leave tomorrow. Wish me luck!!!!