My failed attempt at powder coating

[itsnotanova]

I'm not afraid to try new things, especially if I can save a buck doing it myself. I've been very successful at learning how to do things for myself and take pride in my DIY ability. It's who I am and the reason I'm able to do what I do for a living. Most things aren't that hard to do once you learn how to do them. So many people are afraid to fail and I don't get it. So you messed up. Keeping trying until you get it right! Well, I'm getting tested on that motto. I've always wanted to try powder coating ever since they came out with those at home kits. I finally bought myself one of those kits and got a oven. I got the oven for free from a friend who was remodeling her kitchen a few years back. It took me a few months to finally find some wheel to powdercoat and a friend of mine wanted to also try on his spec boxster wheels. It was a learning experience for both of us.

We started out by getting the wheels sandblasted.


We took this wheel

And hanged it in the spray box like this

This is how it came out of the oven

If you look hard you can see lots of flaws in the finish. We tried first on some scrap metal but probably should have practiced more before moving onto wheels. Getting the powder in the lug holes was very difficult. We did one wheel and called it quits. While we were defeated, we weren't done with powdercoating just yet. The conclusion we came to is that it might be best to let the professionals do larger objects. I have a set of calipers I'm going to attempt next.

[rexcramer]

Good on ya for trying. Did you pre heat the wheels before spraying?

[Flavor 987S]

For great Ceramic Power Coating, work with CCP Coatings in Detroit, or FD Motorsports in California.

[jcslocum]

That looks like impurities in the base metal coming up or the surface just not cleaned properly. You need to pre-cook some stuff to get them to gas off as well. Let them cool and then powder coat.

[steved0x]

For wheels is powder coating more durable than spraying paint like you would on the body of a car?

[BoxsterLS376]

Yeah I think the wheels needed more prep work before moving forward with the coating. Hard to say without seeing them first hand but based on the pre-coated pictures I can see a lot of scuffs and bumps which all contribute to the finished product, that and a proper cleaning like jcslocum said.
I wouldn't give up just yet, practice on something smaller first. You should see how crappy my first few attempts at fiberglass have been, UGH!
$.02
J

[jb92563]

Its good to document failures as well so we can avoid the techniques that did not work.
If someone else had documented their experience with this product you probably would have been successful on your first try.

What was the product you used?

A few things came to mind and after a googling of Powder-coating since I know nothing about it, but am curious and would like to add it to my repertoire of projects skills.

Did you check the oven temp with a thermometer of some type.
I found out that my oven at home reads 20F higher than actual. Our last thankgiving turnkey had some slightly raw areas, which prompted me to check afterwards with a infrared thermometer.

I also read that electrostatic powder coating ensures better end results.

There are also different kinds of Thermo Plastic, each suited to specific materials and application techniques.

I didn't realize that powder coating is actually just a thermo plastic that is deposited on the underlying material.

[itsnotanova]

Thanks for your help guys. The coating had covered up the pre-blemishes pretty good. Most of the finished blemishes look like fisheye or orange peel. A lot of that was caused by me trying to get powder into the lug holes. I should have started with the hard to reach areas first and then a final cover of the powder. I had cured the wheels the day before and that might have a little to do with the blemishes. We had a few things working against us. First, the sandblaster didn't do that great of a job. We didn't cure and clean them good enough. Our ground wasn't that great. Moving from the spray area to the oven was difficult. The oven was too small. I couldn't even fit my 18's in it. The oven temp was questionable too. We had two digital thermometers and they both were reading differently. You can tell when the powder has set because it will get glossy, and then you bake for 20 minutes. But it was still a guessing game on the temp. My friend wants to borrow my equipment and keep trying. My cheap Chinese 18's wouldn't fit and I'm hesitant subjecting them to that heat, so I'll be painting mine. To answer Steve's question. Powder coating is so much more durable than paint. It's not bullet proof and it has it's cons, but it's better than paint.

[jcslocum]

Woody, you need to start with smaller parts to get a groove going. I have the Eastwood setup and it works very well on my engine parts, brackets, suspension parts, etc... We started small and can now do a hardcover book sized parts perfectly. Complex parts are way to easy to overcoat and just take time and experience.

Keep it up and you will get it right.

[Gilles]

Originally Posted by jb92563

I also read that electrostatic powder coating ensures better end results.

I have never done powder coating, but remember clearly while visiting a manufacturer of heavy duty outdoor machines that they use electrostatic process to help the powder to adhere into the metal parts...?

[jakeru]

Hi Woody, I don't want to discourage you from learning how to power coat, but I have doubts it would be more durable than a good 2-part catalyzed polyurethane coating. Even brake parts cleaner won't phase that stuff! It's even available in rattle cans now. (But it's so not cheap, though). Best of luck and thanks for sharing your learnings!

[mikesz]

Good for you Woody! Honest! I feel the same way, DIY'er. Perhaps you should let the pros do your set of wheels and practice on some others that are not as important. Sometimes the right equipment makes a big difference. Live and learn don't be discouraged.

[Swhitcomb]

Been powder coating at home for years now. Those wheels being aluminum would've benefited from prebaking. Aluminum is porus and tends to absorb grease, oil, and all kind of bad things. I typically prebake them for about 30 minutes at about 450 then cure them at 400.



That's one I did for my Bug. The orange on the edge is just paint overspray. I can't even begin to describe how ugly that wheel was when I started.

[jb92563]

I also read that there is another technique when you don't have the electrostatic powder sprayer.

You bake the part uncoated first and then take it out and immediately spray the powder coat but being carefull no to put it on too thick.

It melts onto the part immediately and then you still need to put it in the oven again to complete the baking process.

Doing it this way solves the problem not having the static electricity to hold the paint on the part initially.

This technique also helps with aluminum parts to reduce the out gassing that occurs when baking as the part is already hot and out gassed BEFORE you apply the powder coat and reduces the bubbles, orange peeling, fish eyes, rabbits feet, wolf bane and other assorted things ending up in your finish.

[Swhitcomb]

Out gassing is exactly what I was talking about. And yes, power will immediately stick to a hot part. I do it all the time. Getting a good result consistently takes practice. I've been doing it since 2009 and still have a part I'll have to do over sometimes.





That's the engine I did for a Bug I'm building. Orange is a really tricky color. Hard to get enough on the part. The silver vein pictured is a base clear. Time consuming. I love it though.

[Tcar]

Originally Posted by itsnotanova

Getting the powder in the lug holes was very difficult.

I've always heard that you should not powdercoat in the lug holes.

I know you're not supposed to paint in the lug holes for sure.

[mgfranz]

I know its digging up an old thread, but I too got the PC bug this year, and the first thing I learned is even with a thorough sand blast and cleaning, its VERY important to clean all surfaces with pure acetone, even after pre-baking, (pre-baking is not a necessary step imho). Wipe all surface twice with a lint free rag, high pressure air to get rid of any lint or dust, then apply powder or manufacture recommendations. I follow these steps and get desired results, though I haven't tried rims yet.