Powdercoating the 14" Bundts picture - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 12-02-2011, 12:22 PM

Quote:

Originally Posted by KAdams4458

You could shoot an automotive clear over powder, but I've never done it, and on something like an automotive wheel, I wouldn't want to. Powder coat is just more durable in harsh environments, and a wheel on a car lives in a seriously harsh environment, if you really stop to think about it. There are several clear powder coat finishes available, and many of them can be further altered with gloss reducers.

Now, if you really want your mind blown, consider the fact that there are acrylic clear powder coat finishes available with low enough cure temps that they can be successfully applied over automotive paint without damaging it. Harley Davidson and BMW are both making use of that exact finishing method these days.

Now that was what I was think would be the problem.

If you powder coat in a colour and then bake - how do you cure the clear powder coat?

Answer seems to be it is cured at a lower temperature - simple eh?

Other problem though - particularly for a car body - can you buff to a shine like an automotive clear coat?

KAdams4458 · #17 12-03-2011, 02:57 AM

Quote:

Originally Posted by Army

Now that was what I was think would be the problem.

If you powder coat in a colour and then bake - how do you cure the clear powder coat?

Answer seems to be it is cured at a lower temperature - simple eh?

Other problem though - particularly for a car body - can you buff to a shine like an automotive clear coat?

The clear powder can cure at the same temp as the previous layers, or at a lower temp, as required. Once a powder is cured, it doesn't melt again when you take it back up to the same cure temp. Most are pretty stable, and won't even discolour when baked again.

And yes, powder buffs out just fine, so long as it's supposed to be glossy to begin with. Acrylic clear really shines up nicely. I've buffed it out several times.

Stretch · #18 12-03-2011, 05:57 AM

Quote:

Originally Posted by KAdams4458

The clear powder can cure at the same temp as the previous layers, or at a lower temp, as required. Once a powder is cured, it doesn't melt again when you take it back up to the same cure temp. Most are pretty stable, and won't even discolour when baked again.

And yes, powder buffs out just fine, so long as it's supposed to be glossy to begin with. Acrylic clear really shines up nicely. I've buffed it out several times.

Are these powders thermoset plastics?

Thermosetting polymer - Wikipedia, the free encyclopedia

KAdams4458 · #19 12-03-2011, 09:05 AM

They are thermosetting. So, most of them can be brought back up to cure temp, and for some powders even above cure temp for limited periods of time without causing any damage to them. Clears and white are the first ones to have problems, as they can yellow or brown a bit.

I had an oven mishap a few years ago that demonstrated the temperature resistance of powder coating quite well. I was applying a clear coat polyester powder(400 degree cure) to some cast iron parts for one of my drill presses that had already been coated in a partially cured polyester hammertone powder finish, and the temperature control of my oven went haywire and ramped the parts up to 550 degrees before I noticed what was happening. I thought the parts would need to be stripped and refinished, but sure enough, they came out of the oven matching the colour and gloss of the other parts for the same machine that were done in a different batch. (That high temp of 550 was verified by a temp probe clipped to the cast iron table, so the small parts may have even been a bit hotter.) To this day, that drill press is still in my shop, and the parts that were over-baked are still holding up just fine, and look exactly the same as the parts that were not subjected to too much heat while curing.

JHogan · #20 12-05-2011, 05:27 PM

I talked with the local PC shop owner today about the colors available. NIC color is supposed to be Mercedes silver. Star silver UMB 5045 Metallic prismatic powders.

Here it is against a passable spare for color comparison.

I understand I'm not going to get right on the money.
I would like to see RAL 9007.
Someone pls give me a distributors info so I can get a swatch/sample.

Terry Walters let me know today that it would be 50.00 extra to strip the wheel that was PC'ed the wrong color. Can't decide how I feel about that. I did tell him to match it the best he could. So I'm at fault too.
I may just give him 100.00 and thank him for cleaning and bead blasting my wheels, take them home and rattle-can these f*ckers.

What a saga this is turning into.
Jay

I

KAdams4458 · #21 12-06-2011, 12:22 AM

I'll hold off passing judgement on the applicator at this point, but did you ever find out if the wheel you received was even clear coated? I did say that the Mercedes Silver from NIC wouldn't match. Hang on a bit. I will go hold a 9007 sample from my RAL colour chips up next to a Bundt that still has the factory clear coat. I have to dig the wheel out of a pile, and my spine is really acting up today.

I can also see if I can find a good applicator close to you that can do things correctly. We all network.

I know for sure that there is a guy in NC that does fantastic work, and even has experience with at least one set of Bundts.

JHogan · #22 12-07-2011, 06:47 AM

The wheel that was powder coated was only done on the front and no clear coat was applied.

Jay

KAdams4458 · #23 12-07-2011, 08:53 PM

Quote:

Originally Posted by JHogan

The wheel that was powder coated was only done on the front and no clear coat was applied.

Jay

So, why then would be charge you to re-do something he did wrong to begin with? A clearcoat is required, and the entire wheel needs to be coated, not just the face. You have not only me, but the powder manufacturer telling you the same thing. I would point out to him that he hasn't even done the job properly once; Why charge $50 to remove the powder he misapplied regardless of colour?

Whether or not this guy is actually honest, he obviously doesn't know enough about powder coating to be offering it as a service through his existing business. It's time to take your wheels and walk. I wouldn't even bother having him remove his botched work for free, as someone can very easily damage the wheel trying to blast powder off of it.

I got caught up trying to install a windshield the other night, and never got to finding anyone near you that does good work, or take that picture I promised, but I will do it. I actually just tried looking a guy up for you, but the forum I know him from is down right now.