Filling/painting in engraved metal

[ARKM]

Hi all.

I occasionally do saltwater electro-etching on aluminum and other metals. Not for PCBs but for props. I have some bare etched aluminum pieces and on some, I want to fill in only the etched areas with gold and on others, just black. Some of the designs I have etched are quite intricate, small and not very deep. The resist I use for etching is laser printer toner. One option I have is filling in the etched areas before removing the toner but I use acetone to remove toner and as I'm sure a lot of you know, acetone will also remove most anything else like paint or glue.

Whether I remove the toner first or not, is there any material, (liquid gold leaf, Run N Buff, etc,) that will work on only filling in the etched areas? Any special techniques I need to know to make this work? Any help would be greatly appreciated. Thanks.

EDIT: I should mention that most of what I etch is aluminum tube with a 1.5 inch outer diameter but I also etch on flat metal as well. I'm guessing that some of the techniques used for flat metal will not work on tubular metal.

 

[jordandau]

What if you etched it, then painted it all the color you'd like to fill, then sand the tube after wards. The sandpaper probably wouldn't go in the cracks if you're holding it around the tube, you'll remove the top layer and the valley's will still have paint in them.

 

[ARKM]

I've tried that actually and sadly, paint in the etched areas also tends to come off. It's great for a weathered look though.

 

[CSMacLaren]

What about solder?

 

[cheech9898]

If you can't sand the top surface after painting or wipe the wet paint off the top surface after painting to leave the etching colored, it sounds like the etching is not very deep/not deep enough. You may have to etch deeper, or if that's not possible you'll have to just hand paint the etching with a fine line brush or if it's wide enough a paint touch up pen.

Only other thing I can think of to try is a liquid paint mask/stencil and see if you can hand cut your etchings; Or carefully paint the liquid mask on just the surface post etching & toner cleanoff. And then paint the recessed etching & remove the mask.

Remember if it's aluminum you may need an etching primer for proper adhesion.

 

[ARKM]

Solder will not work for what I am trying to accomplish.

Since I do saltwater electro-etching, I cannot have any paint or other form of resist on the parts of the metal were I need etching to occur. Also. my designs are too fine to paint by hand.

I have not tried wiping off the wet paint as I just assumed that if the paint is wet, it would all come off. However (and I know I should have done this before posting this thread so you all have my apologies) I just found some videos on youtube that show how to fill in the etched areas on firearms. Not only do they wipe off the paint while somewhat wet (sometimes even after it's dry), they wipe it off using non-acetone fingernail polish remover, mineral spirits and sometimes even paint thinner. This tends to remove some of the paint/fingernail polish in the etched areas so it usually takes two to four coats but it seems to work well. I'm not sure what I etch will be deep enough for that plus my "valleys" are more like a half pipe instead of a half square but maybe it will work. I'll have to give it a try very soon. I will post my results in this thread.

Thanks to all of you for your input. I appreciate it.

 

[Darth Lars]

You could get a better result when sanding if you glued sandpaper to a perfectly flat block of metal, and used that. Then there isn't any flex in the sandpaper.
I prefer contact adhesive for this.

 

[ARKM]

I did try sandpaper on a hard-ish rubber sanding block but no glue. Your idea sounds a lot better. I will have to try that as well. Thanks for the tip.