Need Help etching Aluminum

[TheDesignShop]

I'm in some dire need of help.

I have been etching aluminum with Caustic Soda. It seems to work pretty well. The process I have been using has been extremely tedious. Here is what I do:

I screen print a reverse image on the aluminum. I apply the caustic soda to the exposed areas. After the acid etches, I strip the ink then register the image to a screen that is right reading then print again.

I came across someone who mentioned etch and fill. This technique is slightly different than the one I'm using and is more accurate. Does anyone know of this process? I have searched everywhere and come up short everytime. I was told I would still screen print, but that was the extent of their knowledge on it.

Thanks

 

[Roff]

Can you etch and then paint the entire surface, cure the paint, then mill or polish off the excess?

 

[TheDesignShop]

I thought about this

This was an option I had thought about. The pieces are so thin to begin with and since I can't go too deep with the etch, it isn't a process that seems to work.

As for the polishing, This is something that I might try. I found an etch resist ink that can be removed with acetone. If I fill the etched area with an enamel and bake it in, then strip the remainder with acetone, it might work. I get the ink on Monday, I'll try it, what else do I have to lose, except a couple parts.

Thanks

 

[Oznog]

Use photoetch! I'm familiar with 3 types- one's a liquid which develops in xylene, a spray which develops in a mild base and strips in a stronger base, and a laminated film, which develops in mild base and strips in a strong base.

For the second & third, you'd need to use an acid etch to avoid harming the resist. Aluminum etches quite well in acid, you need to keep the concentration fairly weak to avoid thermal runaway though.

 

[TheDesignShop]

Thanks

Where can I find more information for photoetch? The process, materials etc.

Thanks again,