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Powdercoating Aluminium
loggyboy - 9/12/11 at 12:37 AM

Cant seem to find much information on the subject, but is there any special prep needed when powdercoating ally sheet?
I know you can get special primer for steel suitable as an undercoat for powdercoating, but not seen one for ally.

INDY BIRD - 9/12/11 at 12:39 AM

I think it is just an etch primer etc then powder coat, I'm sure they will come along and say otherwise that's what I did and was all ok,

loggyboy - 9/12/11 at 12:57 AM

Are etch primers clear finish? I was planning on trying out the clear powdercoating, so will be pointless if the primer is a typical dull shade!?

Irony - 9/12/11 at 09:29 AM

I have powder coated polished ali with clear powder coat. Seems to be okay so far - I did my v8 rocker covers. Admittedly it might not last but it seems fine just sitting in the garage. I use electrostatic magic clear

mcerd1 - 9/12/11 at 09:41 AM

not cheap but there is this stuff:

http://www.frost.co.uk/automotive-paint/por15-ap120-metal-prep.html

and this stuff instead of clear powder coat

http://www.frost.co.uk/automotive-paint/por15-glisten-pc-and-hardener-activator.html


I picked up some ages ago, but I've never got round to trying it yet....

afj - 9/12/11 at 09:41 AM

How is that electro static magic always looks good at the shows

loggyboy - 9/12/11 at 11:49 AM

quote:
Originally posted by afj
How is that electro static magic always looks good at the shows


Very good so far.
http://locostbuilders.co.uk/forum/37/viewthread.php?tid=139736

Irony - 9/12/11 at 01:29 PM

The electrostatic magic is a good system but I don't think they supply very good instructions with the kit. Admittedly my car is not on the road and is still far from IVA but I have good results from the electro kit. A few things I have found

1. Others on here will disagree but I think oven curing is the only way to go. If its a big part with a lot of mass (say a engine mount) the heat from heat guns will not be enough. It dissipates to quick and doesn't seem to cure properly

2. Seems to me that multiple coats on top of part cured coats is the way forward. I have actually put it on so thick it's nearly dripped during the curing process.

3. Heat the metal up first

4. The high crome is crapppppppp - don't bother

With these in mind it's possible to get good results. I like it because you can obtain good results very quickly. You can get a part off the car and powder coat it and have it back on the car much faster than spraying or paint as there is no curing time.

r1_pete - 9/12/11 at 02:30 PM

How do you go on with adhesion?

I understood the key to lasting powdercoat was to have the component blasted to provide a rough keyd surface, followed by a chromate primer.

Irony - 9/12/11 at 02:36 PM

quote:
Originally posted by r1_pete
How do you go on with adhesion?

I understood the key to lasting powdercoat was to have the component blasted to provide a rough keyd surface, followed by a chromate primer.


Seems to be okay - a lot better than whats achieveable out of halfords rattle cans as far as i'm concerned. I have tightened a few m10 bolts up and cracked it. I powder coated my engine lifting eyes and then lifted the engine out. That chipped them. I only powder coat stuff like brackets and stuff. Biggest thing I have done is my rocker covers in clear over mirror polished ali. Been okay so far.

Dunno what cromate primer is - the electro static people don't mention it

[Edited on 9/12/11 by Irony]

r1_pete - 9/12/11 at 03:01 PM

I ask because I've always taken things to a coater in Castleford, and they explained their process as blast - chromate - coat. So if I could do bits and bobs myself to a reasonable standard, it'll save me some miles.

TAZZMAXX - 9/12/11 at 03:30 PM

quote:
Originally posted by r1_pete
I ask because I've always taken things to a coater in Castleford, and they explained their process as blast - chromate - coat. So if I could do bits and bobs myself to a reasonable standard, it'll save me some miles.


Aluminium is generally not blasted as it still won't key without an etch prime or chromate treatment. Etch prime is physically wet sprayed and chromate is an immersion process to the best of my knowledge. I've had both sorts done, generally the chromate treatment is used on larger batches of components but would be dependent on the coaters preferences. With regard to steel components, provided the base metal is clean, free of oil and surface contaminants it does not need to be blasted.