DIY powder coating

[CJH]

Was anybody else tempted by the DIY powder coating system being sold at Busfest? I'm sure it won't be as easy as it looked on the stall, but I thought I'd give it a go, so I got a deal on the kit and a few different finishes.

I've been prepping a few pieces ready to give it a go. I bought a rusty old 'early' cooling system water pipe at Busfest, and I had a rusty old throttle cable bracket. I took them along to a grit blasting cabinet at work this afternoon, so here's a couple of 'before' and 'after' shots.







There's some heavy pitting, particularly on the throttle cable bracket, so I'll probably give them a coat or two of epoxy primer to fill some of the pits before attempting to powder coat them. I was thinking gloss black for the bracket, and a chrome finish for the water pipe.

I also had an intake manifold that I wanted to clean up. And here's the real reason I'm posting before I've got anything to show for the powder coating - I just had to share a photo of the way the aluminium casting has come up. Here's the before:


and after a scrub with paraffin and a go in the grit blaster here's the after:


Any thoughts on whether this can be powder coated? The curing process requires the item to be held at 180 degrees for 10 minutes. Is that ok for an aluminium casting? It's tempting to just clear coat it to keep it looking this good, but depending how the chrome finish comes out (which is actually a clear-over-chrome two-step process) I may try that. The water hose spigots could do with some metal epoxy to fill some of the pitting first.

I just need a way to cure these items then I'll be ready to go. Apparently the curing process gives off poisonous vapours so you're not supposed to use the oven you cook in. I would have thought that vapours will leave the oven when you open the door, but what do I know. Anyway, I'm on the look-out for a second-hand oven for various 'curing'-type jobs.

[itchyfeet]

did diy powder coating at school in metalwork class 30+ years ago

aluminium castings are regularly powder coated, we used to do 100+ thousand a year at work larger than that in a full pcp with ovens and moving track hangers.

getting it up to temperature will be your problem ( casting probably needs preheating) and consider what will happen to polyester when at normal engine running temps, I'd think it will degrade.

powder generally does not stick to porosity, dirt, or other coatings, it' normal to pretreat ( chromate conversion IIRC) and wash the part in fresh water but I'm no chemist.

[keith]

I dont think that the temp will affect it at all. To get good adhesion you normally have to etch prime aluminium to get powder to stick.

Happy to help out with p coating if you can do the prep......

[Oldiebut goodie]

If you are going to only do small pieces how about getting one of those small ovens meant to go on the worktop? You could then do it outside easily without wrecking the house with the fumes. I remember doing stuff in metalwork at school in an oven - no warnings about fumes in those days!

[CJH]

getting it up to temperature will be your problem ...

The fella on the stall said that if a piece won't fit in the oven it could be cured in sections with a radiant heater. Heating the parts is the main problem though, that's true. But if all I end up using it for is small parts that will fit in an oven, then that will be fine - it's apparently harder to get a bad finish than with painting, as only the right amount of powder will stick so runs are not likely. So the fella said anyway.

[CJH]

If you are going to only do small pieces how about getting one of those small ovens meant to go on the worktop? You could then do it outside easily without wrecking the house with the fumes. I remember doing stuff in metalwork at school in an oven - no warnings about fumes in those days!

Yes, I'm considering one of those. But I've also got a kind offer from a friend looking out for a scrapped single oven (fitted type) - apparently they will run off a 13amp plug, so yes, I would use it outside.

[CJH]

I dont think that the temp will affect it at all. To get good adhesion you normally have to etch prime aluminium to get powder to stick.

Happy to help out with p coating if you can do the prep......

Thanks Keith - good info on the etch primer. And good to know you do powder coating too, but getting someone else to do it is no fun!

[keith]

This is our paint plant.....

http://youtu.be/8MPTIcW6d_Y" onclick="window.open(this.href);return false;


Many a westfalia bit has passed thru it.....

[Oldiebut goodie]

I am awaiting the spurious links from this one!

[Dazco]

That's a megga impressive set up Keith in the kitchen
CJH do you have a name for this powder coating product or a link to who you got it off , thinking of giving it a try on a few bits and pieces .

[CJH]

Wow that's quite a facility you have there Keith.

CJH do you have a name for this powder coating product or a link to who you got it off , thinking of giving it a try on a few bits and pieces .

I bought an EasyCoat system from electrostaticMAGIC. He was doing some good deals at Busfest. It's essentially just a spray head for a compressor, that charges the powder particles with respect to the piece you're coating. There's no spray booth or oven, but as it's firmly aimed at the DIYer those are the bits you should be able to improvise yourself.

[CJH]

I've had a go with this kit today. It's pretty easy to get good results. I did the flange from the thermostat housing on my early cooling system.

Here it is after grit-blasting.


Here it is after spraying with gloss black powder and hanging it in front of a halogen heater. Note the furry finish before the powder melts.


Here it is with the powder just starting to melt.


Here's the finished article after a couple of coats. The first coat was fine but I wanted to reduce the look of the pitting.


And here it is installed back on the grit-blasted thermostat housing, complete with new stainless bolts, all ready to go on my new engine.

[Dazco]

That looks fantastic

[CJH]

I was surprised, to be honest. The fact that a total novice can get a decent finish says more about the process than it does about the novice. This same novice's first attempt with a spray can was nowhere near as successful! (Many attempts later and it's still a bit hit and miss whether I'm going to get a run, or miss a bit).

Provided the earth lead is attached to the piece while spraying, the cloud of powder tends to find it's own way into all the nooks and crannies, and it's virtually impossible to put too much on as the powder layer prevents more from sticking. So no runs, and no missed bits. And the finish seems tougher than a spray paint finish.

The heat source is going to be the limiting factor though. I'd love to tackle a bumper for instance, but I'd have to coat it in one go and then cure it in sections, and I'm certain the uncured sections would get blemishes while I'm curing another section.

[itchyfeet]

if you heated from one end of the bumper slowly along to the other you should not end up with a noticable line