anodizing

[EKDENTON]

Anyone do any of their own anodizing? I am going to try to do some on some of the amp chassis parts. Most of the videos I see are just very small parts so a chassis cover may be to large to anodize. The chart says a pc the size of a marshall chassis 2 sq ft  can be done at 12 amps and 15vdc for an hour. The cathode will need to be larger than 2 sq ft or the cathode will be anodized and not the chassis. I bought a power supply that is constant current constant voltage 30v 20a.


This chemist came up with a way to anodize without using sulfuric acid which is pretty dangerous to work with and dispose of. He found that Bisodium sulfate works equally as well as battery acid and is only a mild irritant. He still suggests using gloves and eye protection in case of splashes though.


http://www.observationsblog.com/sciencetechnologyexperiments/anodizing-and-dying-aluminum-without-battery-acid

[drgonzonm]

Sodium bisulfate, is still an acidic product, 5% solution has pH less than 1 Do a search for MSDS. 

THIS PRODUCT CAN BE DANGEROUS   

[EKDENTON]

Bisodium Sulfate is the alternative to working with Sulfuric Acid. Working with battery acid is far more dangerous. Most people use the battery acid to anodize however, you should always wear gloves and eye protection when working with any chemicals. I am using the Bisodium Sulfate since it is the least dangerous of the two.  Kinda like the capacitors in a tube amp.....if they are charged up and you touch them they could kill you but if you take proper precautions they are fairly safe right?

[drgonzonm]

Bisodium Sulfate is the alternative to working with Sulfuric Acid. Working with battery acid is far more dangerous. Most people use the battery acid to anodize however, you should always wear gloves and eye protection when working with any chemicals. I am using the Bisodium Sulfate since it is the least dangerous of the two.  Kinda like the capacitors in a tube amp.....if they are charged up and you touch them they could kill you but if you take proper precautions they are fairly safe right?

At suggested g/L, The aqueous solution of Sodium bisulfate, is somewhat less dangerous the equivalent diluted sulfuric acid on a scale of 1-10, where h2so4 is 10, the bisulfate is 7 to 8.  You are looking about 1.5 molar solutions, either way.
After working with similar chemicals over 30 years, I would recommend you finding someone to anodize the chassis.  Contact automotive specialiity shops for leads on who does anodizing. 

[PRR]

> may be too large to anodize

Where I worked, the buildings were clad with aluminum panels 4'x12', with tightly specced anodize.

So it can be done. Uniformity is another thing. (And maybe not so tough for you-- these building panels had to butt-up with negligible difference of shade, you won't notice a slight shift from end to end of a single piece.)

[EKDENTON]

I've been able to successfully anodize small parts. Like you said PRR getting uniform color even on a small part seems to be difficult. I wasn't going to try a chassis but rather a PC of 3/16 thick aluminum about 7" wide x 12 long x 7" tall. Its a u shaped part that bolts to the chassis and protects the tubes. I am pretty sure I wont have any trouble with the anodizing part, just the coloring part. I could just leave it clear I guess.