Powder coating aluminum components

[lamsawyer]

I'm getting a frame built up, and I was hoping to get the aluminum stem powder coated to match. However, I'm seeing a lot of conflicting information on whether or not this is a good idea for smaller aluminum parts. Does anyone have any experience trying to do this?

[joosttx]

I have DIY powder coated an aluminum bike rack. It turned out great. So technically it can be done with success. However the word on the internet is that the baking process will weaken the aluminum catastrophically. I did not see this with my rack. Personally, I would not do it on a stem-- breaking a stem vs breaking a rack are two different things, ya know. My suggestion word be to bet a frame builder, Winter Bikes, to make you a steel stem to powder coat.

[Luwabra]

I’ll let you know 😂 I dropped a stem off w my frame last week. Really the heat? The guy was baking a frame when I got there and i want to say it was 350° no more than 400° ever he said. I have a hard time believing it would structurally change at 350° for a few minutes. Unless they are baking it hot to remove oils etc before coating it was powder maybe.?

[rccardr]

Powder coating on aluminum by a knowledgeable professional is no big deal. Have had dozens of Cannondale aluminum frames powder coated over the years without a single failure. So, there's that.

Only issue with a stem is clearance into the steerer if it's a quill. If threadless, no problem, just keep the powder out of the threads.

[joosttx]

I’ll let you know ������ I dropped a stem off w my frame last week. Really the heat? The guy was baking a frame when I got there and i want to say it was 350° no more than 400° ever he said. I have a hard time believing it would structurally change at 350° for a few minutes. Unless they are baking it hot to remove oils etc before coating it was powder maybe.?

The general recommended bake temperature for powder is 425F. I think I recall professional outfits can heat to 500F.

[loxx0050]

Plenty of local powder coating shops to me do so on alloy car wheels all the time which most are aluminum (either cast or forged). They turn out fine and I've never heard of a alloy wheel failing due to powder coating.

There is aluminum cookware and bake ware. Even some car engine parts are aluminum (BMW Z4 is an example, I recall from watching one of those shows that feature impressive engineering feats/challenges). I used to work for a aluminum casting company and we made plenty of jet engine parts out of aluminum for the air inlets. I wouldn't worry about it personally.

[HenryA]

This might help:

http://digitalcommons.lmu.edu/cgi/viewcontent.cgi?article=1009&context=mech_fac

But keep in mind you probably don’t know what alloy the stem is and unless you use a coater who knows about coating engineered parts you might get something less than safe. How hot and for how long was it hot? A coater who regularly runs steel porch railings may or may not be a good choice for a safety critical part. A bike stem is very much a safety critical part.

[lamsawyer]

This is all super helpful information, thank you! The stem is a Deda Zero 100, which is 2014 alloy. I'll keep asking around, but worst case scenario I can figure something out with wet paint.

[Kontact]

As the article indicates, powder coating has high and low temps. The higher temps are in the same range that aluminum (and some steels) are heat treated in.

There's also baked spray on enamels, like gunkote. They bake at 300F.