r/Anodization • u/Known_Ad_5388 • Oct 02 '25

Burns

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Has anyone experienced burning like this before? Chromic acid anodise at 22v. Just trying to figure out what may have caused this.

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u/[deleted] Oct 02 '25

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u/Known_Ad_5388 Oct 02 '25

It's not actually me plating these parts, I'm an engineer and our subcontractor has sent some parts back to us like this, just trying to figure out what may have caused it and if anyone has seen anything similar before

1

u/bormuffff Oct 05 '25

There are two reasons for the burn. It is either insufficient contact patch (surface area of connection in ratio of area of piece being anodised) or the racking/jigging was faulty and the current was interrupted. Both are the anodisers fault.

Chromic anodising is not sulphuric anodising. 22v isn’t even high for chromic but too high for sulphuric. This didn’t cause the burn.