Aluminum Powder Coating Outgassing

[jtravisbayne]

My powder coater has had my sheet metal for a little over 3 weeks. They finally got caught up enough to coat my parts this morning. They called this afternoon and said they were having trouble with outgassing resulting in small pin holes in the powder coating. Has anyone had this issue? I cleaned all of the parts with denatured alcohol before I took them over to their shop. I wouldn't think that contributed to the outgassing especially given how long the parts have been sitting since I cleaned them, but perhaps I'm wrong. They said they could strip them and start over which will take even longer, so I'm probably going to take them as is so I don't hold up the build any longer.

Just curious to see if anyone else has experienced this. If I screwed up with the cleaning method please chime in so hopefully someone can learn from my mistake.

[wareaglescott]

What is outgassing? Have not heard of that occurring before. Seems like panel prep should be included in their price or did you specifically negotiate a cheaper price if you prepped them?
Will they give you a discount?

Take a look and see what you think. If it slightly bothers you now chances are it may really bother you in the future when you see it day after day and then it will be to late to correct. Don't let them rush you into something you may regret later as bad as it stinks to wait it may be worth it.

[aarvig]

Outgassing...sure if the panels aren't properly prepped. Probably not really outgassing, more like poor adhesion. Is the powder coating being put on bare aluminum? If so, the panel needs to be prepped. Nothing sticks well to aluminum unless its properly prepped.

[coyobra]

Hi J. - I had some of my panels powdercoated and also cleaned them off with denatured alcohol. I didn't wait to bring them down to my powder coater and they had them completed in less than a week with no problems. I have a neighbor who said that you shouldn't wait to long to paint, powder coat etc after prepping them. The aluminum, when exposed to the elements will tend to start oxidizing even though not noticeable in a short period of time. Not sure if that's true or not and if that is your outgassing problem. Just a thought.

[jtravisbayne]

They didn't prep them. I asked if they needed to bead blast them and they said no. In hindsight I wish I had insisted on it. They sent me pics. It's noticeable but no too bad. I'm going to use Lizard Skin on the firewall and the interior areas will be covered with carpeting. If I've got some areas that are really bothersome I can scuff the surface and paint them. Stripping them looks pretty labor intensive and given how backed up they are, I'm doubtful if reworking them could be a high priority as it is a small family run shop.

From what I gather, outgassing is a release of trapped gasses in the metal during the powder coating process. I think it's common with castings. My guess is that it was surface contamination in this instance.

[silver_pilate]

The proper thing for them to do would be to offer you a discount since they didn't bother to do any prep on the bare aluminum which resulted in the finish issues. When I had mine done, they were scared to bead blast them before coating (thought the panels were too thin to hold up without warping), but even then they went ahead and sanded/scuffed the surface prior to coating (did a crappy prep job on a few panels, but at least they tried).

--Nathan

[mikeinatlanta]

Outgassing can happen with cast parts, not sheet aluminum. They screwed something up and want your money anyway.

[joyridin']

I agree with mikeinatlanta. I have powdercoated a lot of aluminum and never have seen outgassing in sheet aluminum. I have seen it quite a few times in castings, but it is usually pretty easy to fix considering the surface is somewhat rough to begin with.

[michael everson]

the last batch of aluminum I had coated did the same thing. the imperfections were very small and couldn't be seen once the car was assembled.
Mike

[jtravisbayne]

Picked them up this morning. They don't look that bad at all. They gave me a big discount and said if there were some parts that I wanted redone they would strip them and recoat. Oddly, I had purchased a battery box from Breeze and it had the same issue as the aluminum, but the battery box is stainless. Makes me think it had something to do with he alcohol or maybe the shop towels on a roll I used to wipe the parts down left a residue behind.