Acrylic paint does not resist

[cheeb]

Just a heads up to everybody who etches enclosures with ferric chloride.

I ran out of enamel and went to acrylic but it turned to jelly after about two minutes and my painted areas were exposed.

So don't use it.

[Seljer]

heh, when I opened this thread I though you were talking about electrical resistance. In which case it is non conductive as far as my experience goes (spraying the bottom of PCBs so they don't oxidize)

[Paul Perry (Frostwave)]

Maybe the acrylic hadn't fully set. (It looks like it 'dries' but it actually should be polymerising). Certainly nail varnish or enamel is going to be right to etch much sooner.

For the experimentally inclined, here's an interestign extension of the traditional ferric chloride etch: adding citric acid to it (citric acid is in lemons, but you can buy it in packets - as a powder - from bakery supply stores or large supermarkets).
http://www.polymetaal.nl/beguin/mape/edinburgh_etch.htm
The theory is, the cirtic forms a complex wiht the iron & stops it forming a deposit & interfering. I havn't tried it, but I'd like to hear from anyone who tries it out.

As a general hint, searching the artistic etching sites, is well worthwhile for anyone wanting to etch boxes - it's ALL been tried!!

[mdh]

Well, acrylic paint is water soluble, isn't it? I don't know about it polymerizing, but I would doubt that it ever gets very resistant to dissolution in water. All of the etchants we use are mostly water, so no big surprise there.

I recently picked up a paint pen (enamel, I believe) designed for decorating ceramics and such. It has a tip that's somewhere between the ultra-fine and fine Sharpies, and does a very good job at touching up PNP transfers. It dries quickly, and is 100% etch resistant.

[Paul Perry (Frostwave)]

Well, some acrylic is waterproof, because it's used to screen print fabrics.
Anyway, it's important to know that at least some acrylic isn't any good as a resist.

[cheeb]

I believe a paint pen is the wave of the future for Mr. Cheeb. Although the effect I got from the acrylic paint etching away is kinda cool for the design I used, a paint pen would be a lot safer and more precise. I have a friend who is much more of an artist than I (I was a printmaking and ceramics major who can't draw and makes heavy use of Photoshop and he is a real artist  ) and he is interested in drawing his own designs onto a box to be etched so it's godo to know that a paint pen is etch resistant.