First attempt at home anodizing

I have a question, would a constant current arc welder work as a power supply for anodizing?
 
I tried anodising some aluminium angle a couple of years ago and used "Dylon" black dye.
They came out light brown to a bronze colour.
Havnt done any since. Might just have to have a go again.
 
Jim,

In theory a constant current welder should work. But in practice, a welder is designed for far more current than is needed for anodizing. This makes it likely that the current regulation at the lower current levels is not very accurate.

For anodizing, there is a "Rule of 720". This states that it takes 720 amp-minutes / sq. ft. to build up .001" thickness of anodizing.

As an example, let's say you have a part that is 8" x 8" x 1/2". This has a surface area of 144 in^2 or 1 sq.ft. If you want to know how much current you need for an hour in the tank, its 720/60 you get 12 amps for a .001" thickness. If you want to go to two hours, it will only be 6 amps.

It is not recommended to use more than 12 amps / sq. ft.

The largest parts I have anodized were .55 sq. ft. yours may be different. To further put things in perspective, I used a 65 watt 19 volt LapTop power supply (I had lying around) and a cheap Constant Current controller I got on fleabay. It works great for the size of tanks (2 gal) that I am using. I am "upgrading" to an old 250 watt PC power supply....
 
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Nice first try. My first try didn't take as well. I always have trouble with maintaining good contact on the part being anodized and not making a shadowed area where visible. I need find something to hold the part and not contaminate the bath. Titanium seems to be the favored metal. Otherwise I've managed to get excellent results just using battery juice and a well ventilated space. I keep a cloth dampened with Baking Soda around for any splashes. Anodizing is a great addition to home machined parts.
 
The only metals that should ever find their way into the anodize bath are aluminum, titanium, and lead. For hobby purposes, aluminum wire is the most common used for the electrical connection, since it is relatively easy to find and is inexpensive. I got myself a one pound roll of MIG welding wire for under $10. It will last me a looong time.

Anodizing shops use special racks to hold the parts. These racks are made of titanium. The titanium wire I found is VERY expensive.

A cloth dampened with Baking Soda is a really good idea.
 
Can you provide more details on your use of the PC type Power Supply and the Constant Current Controller.
I have access to a ton of PC Power supplies but don't understand the Controller part.

Is there a link you could post to the controller?
 
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