Another question for those with more experience:
I had this frame powder coated about 10 months ago. He’s done a fair amount of bikes before, and was even separately recommended by my LBS. There are little bumps showing up all over, and overall it seems pretty fragile. A bar strike caused the top tub to almost peel. I did take the cheap route and use powder he had extra from past jobs.
Is this bad powder? Bad craftsmanship? Bad prep? Is it rusting under and making bumps?
Looks like poor application.
Lots of issues can come up with powder, could be the air used was not dry enough and causes moisture buildup under the coating, surface wasn’t sandblasted blasted or cleaned properly which affects adhesion, or powder wasn’t baked at the proper temp or time.
Agreed, looks like incorrect surface prep to me - looks way too shiny in those pics to have been sandblasted. But hard to tell from photos.
Thank you both, I’ll have a chat with the powder coater.
I’ve had this issue even with expensive powdercoat finishes from supposedly the best coaters in the business. On the other hand, I’ve had PC finishes that held up for a long time with no issues. I understand there are many variables in the process, and apparently it’s tough to control them all. Because of this, I no longer offer a powdercoat option to my clients. Not worth the trouble of dealing with finish failures.
Alex
alexmeadetools.com
Powdercoated around 70 frames last year on my own setup , which is sketchy at best…
Any defects caused by humidity in the compressed air line, water,oil or grease on the substract will show up right out of the oven if not before.
Sandblasting really help with powder adhesion but I’ve done dozens of only clearcoated frames with no issues ( no sandblasting to keep things shiny, rust over times but that’s expected…)
To me the issue here would come from being baked too short /long leading to poor adhesion allowing humidity doing his thing.
