powder or paint

[dboy]

Hi all.

Right question time I have started a new project and am after your advice on restoring some suspension arms and sub frames on my car.

Now i have thought about getting all the parts powder coated but i know this can be chipped and flake off then letting in water and crap then there is the price of getting this done. My other thought was to use a paint like Hammerite will this be better than using powder or is paint a waist of time??

Neil

 

[brightspark]

hamerite is a good enamel as long as its undercoated with a good acid etch first or epoxy2k but not rated just aplied direct on to bare metalwork

 

[graffian]

But Hammerite isn't going to be close to powder durability wise.

 

[brightspark]

But Hammerite isn't going to be close to powder durability wise.

id use acid etch and 2k top coat personaly powder coating flakes off eventualy as the rust creeps underneath

 

[dboy]

only prob with 2k is i dont have the set up (saftey side of things) but i do know i would get a better finish with 2k.

Would i be waisting my time using an enamel paint? I so dont know what is the best thing for me to do lol.

 

[Engineer]

Powder coating is far superior to painting, but only if its done properly! The parts must be primed with a special powder before top coating, and as this is quite expensive most coaters dont bother with it.

 

[graffian]

I gather the full system is, blast, iron phosphate dip, zinc rich epoxy prime then a coat of polyester. They recon the only thing to better it in salt room tests, scratched to bare metal sample pieces, is Galvanising!
My local coaters blast the parts and wack on several coats of epoxy before a top coat, or two. But I know most coating is a quick blast then a squirt of powder.
I got some epoxy of them, it's something like 6 quid a kg, so it actually cheaper than paint.

 

[steveo3002]

hammerite chips off really easy and then festers up if you try and paint over it with another brand

if you can get it blasted clean then por15 / kbs / epoxy mastic will last well and they dry hard ..if theyre too dear then wickes enamel or rustoleum over a zinc primer

 

[MG David]

Graffian, does the zinc epoxy powder have a higher melting point so you can overcoat without damaging it?

 

[Engineer]

Its not a good idea to use polyester powder over epoxy, as in most cases adhesion will be poor, and there may well be problems. In general epoxy powders are used in applications where UV light isnt an issue, as UV pretty quickly dulls the shine on epoxies which are not UV stabilised, or protected with a clear coating.

 

[graffian]

It says in the Azko Epoxy product sheet to overcoat with polyester. The cure temps of the epoxy and polyester are similar. I was told to partial cure until the final coat, which I did, but I cured the filler[JB weld] in the oven[it was either that or wait a day] so probably fully cured the epoxy prior to wacking on the polyester. Wonder if the black is going to fall off;-)