Updated with pics of recoat! Pics added Real time input please Poor powdercoating-need advice.

40Man

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Decided to have my valve cover powder coated. The coater sent me these after the initial coat and before clear powder.

Clearly there was offgassing. Seems unacceptable to me and would appreciate input. The coater took no blame and said it was out of their control.

My understanding is the metal should be preheated prior to coating to avoid this, or to use a powder that stays fluid longer to prevent this.

They are saying "there is a chance sanding it and re coating will not fix it. It is caused from impurities in the metal gassing off while it is heating up during the curing process. We often see this in cast products and is out of our control. Coating it a second time will be another $95 charge."

Seems they should fix for free.

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Jdc1

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Decided to have my valve cover powder coated. The coater sent me these after the initial coat and before clear powder.

Clearly there was offgassing. Seems unacceptable to me and would appreciate input. The coater took no blame and said it was out of their control.

My understanding is the metal should be preheated prior to coating to avoid this, or to use a powder that stays fluid longer to prevent this.

They are saying "there is a chance sanding it and re coating will not fix it. It is caused from impurities in the metal gassing off while it is heating up during the curing process. We often see this in cast products and is out of our control. Coating it a second time will be another $95 charge."

Seems they should fix for free.
If you are unhappy and they don’t/wont accept the blame, count your losses and find someone else. In my experience, you won’t get a better job the second time around.
 

JohnnyC

Long ago TLCA# 2231
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I do not see pictures

It would really depend on how many powdercoaters are near you

Technically I’d say yes their fault .... if it comes out like shif they would not want a bad product attached to their name

Can you go elsewhere?

Burning the bridge of you only choice of powder coasters sometimes is a bigger loss in the long run
 

40Man

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I do not see pictures

It would really depend on how many powdercoaters are near you

Technically I’d say yes their fault .... if it comes out like shif they would not want a bad product attached to their name

Can you go elsewhere?

Burning the bridge of you only choice of powder coasters sometimes is a bigger loss in the long run
I have a large # of coaters in my area.
 

40Man

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Yep...that will go well!!!:rofl::rofl::rofl: My dad put some gear lube in a molasses jar and put it on the shelf in the garage. Mom was making baked beans a few days later and OMG was there hell to pay!!! Let the good times roll.
I've been trying to convince my wife we need a new fancy double oven. Old one would be great for powder :).
 
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I do my own powder coating on small pieces that will fit in the oven. Everything I read about doing old aluminum said to de-grease, heat, de-grease again, and keep repeating until the part has absolutely no oil coming out of the pores. I would say your coater doesn't know his job.
 
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I have no history with trying to powder coat aluminum, but I do know you can not powder coat pot metal, it will bubble just like your valve cover bubbled, perhaps the Landcruiser valve cover is a mixture, a lower grade of aluminum, or had hidden pores. If the metal has pores the oven makes them pop open, and bubbles in the powder coating results (been there, done that).
 

40Man

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I have no history with trying to powder coat aluminum, but I do know you can not powder coat pot metal, it will bubble just like your valve cover bubbled, perhaps the Landcruiser valve cover is a mixture, a lower grade of aluminum, or had hidden pores. If the metal has pores the oven makes them pop open, and bubbles in the powder coating results (been there, done that).
Thanks. I have seen others on Mud that have successfully coated their valve covers, so I think it can be done properly.




I was going to have them clear on top of this, but I have told them to stop. I'll take it to a few other shops for a second opinion.
 

brian

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yeap need to run it through several heat and clean cycles.
alum is even more porous than steel and will really soak up stuff.
 

40Man

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Well I got it back. Attempted a wet sand with 1000 grit. The powder was so thin it immediately took it off to primer. Taking it to another shop this afternoon.

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40Man

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You can easily see those are pores opening up from the powder paint oven.
Agreed. The new coater I took it to this afternoon told me the first coater likely didn't clean and bake it long enough first.

He also told me the chrome powder they used is horrible. They won't use it because it is so poor. Every customer the new shop has had use the chrome issues with it. Guess it is a subpar powder. Will be using a recommended silver metallic this go round.

He also said they put too thin of a coat and undercured the powder. I concurred and had already assumed as much since a 1000 grit wet sand took the powder off completely but left the primer. :/.

The new shop won't guarantee that it won't have more outgassing, but it promised it would be much better than what the first coater did, with minimal bubbles. It will probably be another week or so.

Thankfully the first coater did a decent job on the air box.

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I was gonna say that looks like their powder got moisture or the spray lines got moisture, it creates those balls of powder which cause that, not sayin it can't come from something else but I have seen old/bad powder and contaminated spray lines cause that same effect. Seen it with color too, not just the s***ty chrome powder , which I think is actually a base to be mixed with colors/tints, mainly translucents.
 
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