Anodizing flatness requirements

By MDG Custom Weld (***)

Date 10-09-2008 18:39

That seems really bad just being 10' long.
Maybe it was miss-handled between their place and yours.

By G.S.Crisi (****)

Date 10-09-2008 19:21 Edited 10-09-2008 19:58

Anodizing is an eletrochemical process carried out at room temperature in which a DC flows from the anode to the cathod in an alkalyne environment.
There's no reason for which an anodized piece should warp.
MDG might be right in his assumption.
Giovanni S. Crisi
Sao Paulo - Brazil

By hogan

Date 10-09-2008 19:38

Like I said I don't work with it often. The issue is we match drilled the plates, they were flat at the time. When they came back (about 10 plates) all of them had the same waviness issue. This caused many of the match drilled holes to not line up. Thanks for clearing my way of thinking about anodizing. I'll do more reading up on it.

By MDG Custom Weld (***)

Date 10-09-2008 21:03

Were they all strapped or banded together when transported from place to place?
Maybe they all took a tumble together and tweaked in the same fashion.

The professor is correct, it's an electrical process and does not usually (never in my experience) induce warping or distort a machined part.

By hogan

Date 10-09-2008 21:11

All banded together. But we had two orders from two different anodizes and both are having this issue. All 6061

By aevald

Date 10-09-2008 21:33

Hello hogan, the only other "thing" that comes to mind for me here, would be residual stresses in the material. If this is 6061T-6 it would be heat treated and could possibly have some internal stresses that are being released by the anodizing process. These are just thoughts on my part and I don't have any sort of "proof" that this is actually what is happening. Best regards, Allan

By MDG Custom Weld (***)

Date 10-10-2008 11:15

Wow, this is really odd.
What did the two coating companies have to say about it??
I'm really interested to hear the root cause, we have a fair amount of this done and do not want to go through what you are.
Keep us posted.

By DaveBoyer (*****)

Date 10-10-2008 03:47

Typical anodizing is done at room temperature as Giovanni says, however type 3 hardcoat is done at higher temperature. I can't say factually that that would cause the warping however.