Powder Coating Method?

Hi,

I'm looking to powder coat some 15" steel wheels for my 58. Changin over to disc brakes, gotta have 15" wheels. So I've blasted them and I'm going to be using a Craftsman powder coating system that seems to work real well. (I've coated a few smaller items with it.)

My big question is should I try and put multiple coats of powder on my rims and if so, when/how.

Has anybody done this themselves? Should I put on the initial coat, let it flow and then shoot it again? Just hoping someone else has done this before I waste $20 worth of powder and maybe have to re-blast a wheel or two.

Thanks

 

I've had the best luck by getting the maximum coverage on the wheel at once and then baking it. I tried to re-coat once and it just didn't come out good at all. I'm far from a pro powdercoater but we have done four sets of rims in the home shop that came out pretty nice.

 

Retro,

Have you had any issues with flaking or chipping? I'm just looking to do this once. That's primarily the reason for powder coating. Paint always seems to chip or get screwed up on rims.

Thanks for the advice.

 

The oldest set we did are the ones on my '35 sedan. It was three years ago and over 12,000 miles. I have just a few chips around the lug nuts but that's all, they still look like new, it's pretty tough stuff.

I'd say the main thing is the metal prep.....has to be clean, dry and grease/oil free with a nicely blasted surface.

 

Several things to observe. Answer to yourself "why" you would want a heavy mil thickness of plastic on your rims. THAT will usually answer your question about multiple coats HOWEVER we do it all the time but for a different reason. Usually we are trying to get a slick finish on a pitted piece of metal. We try to preheat to 400 degrees and then load it with powder so it will flow. The key to a good quality lustre and flow out is to use good quality powder! Generally speaking, Eastwood's powder does not fall into this catagory.

As for the pitted metal, we then sand the powder with 80 grit paper and then re-coat over that. Look at the wheels below that have a heavy coat of Black followed by Red that had to be sanded too. The 3rd application of powder allowed the wheel to be smooth.

 

ok....first the metal does in fact have to be preped right. degreesed etchec and then sealed if possible. the needs to be dried, for est results it needs to be put through an oven. then dont shoot it hot. first off to do this you need experience and a better understanding of thats is going on rather then it cure right away. if the material has powder already on it then there will need to be a change in the charge because it adhears completely different when its a reshoot. if not done right there will be fisheyes and light spots. light spots are easy to find because if it is a smooth texture powder the light spots will be rough, and vise versa with textured powder. the trick is to shooting the wheel with the right arrowfoil that creates the powder to getinto and stay in the cracks. you can cheet by shooting the wheel witht he face looking up. the powder will settle in the crack and thus no need for the second coat. if this sint done then there will be rust devolopment in the cracks. then to the oven, the wheel needs to be in there at the apropiete temp long enough that the metal inside out is the same temp. if not the powder will not cure right and then chipping or other problems will occur. somthing to think about before you just buy somthing out of a magazine is if its indoor or outdoor powder. the chemical makeup could cause the color to fade if its made of polyester base powder. (im pretty sure on that, now that i have to think about it i cant remember exactly) if for some reason you think you need to or you want to reshoot the wheel dont use 80 grit unless you want to take it down to metal for serous coverups. get closer to 220 that way you dont have bad sanding marks. im not familuar with your gun type because at work all we use is nordson equipment form the auto booth to the manual booth to the batch booth. oh ya i do this everyday so i kinda know what im talking about. just to give you an idea on what your gun should be runing at your powder will not need to be higher than a 1 on the gauge and air i like to always be about half. starting with all the hard spots (corners and welds) then try to blend it all together inwhich will hit them again. depending on your tip on the gun and how narrow the partern of spray dont ever get close with a narrow partern because you will have runs in the finish. if you want a good smooth finish just haze the wheel back and forth with overlaping strokes. easy way to hang the wheels are to use wire or steel bands and go around the inner wheel inbetween the tire beads. that way theres no hook mark or anything like that. i would strongly suggest doing a practice wheel to learn as much as you can from. when you shoot rework depending on weahter or not its ferrous or non ferous metal the kvs and kws(not for sure on the electic measurements) need to change. just like with liquid paint glosses will scratch very easy and unlike liquid paint you can not do anything about it, its permanent. powders to consider would be sherwin williams, dupont, tiger, spraylat. let me know if this confuses you any more and maybe i can clear it up.