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

 

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

 

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

 

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.

 

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

Thanks again,