Could formic acid be used in etching PCBs?

[jpm83]

I'm talking about this stuff. http://en.wikipedia.org/wiki/Formic_acid The smel of it is quite strong but I think it would be quite cheap.

Janne

[Minion]

I don"t know about formic acid but it doesn"t seem like it is corrosive enough to be a good etchant.... I personally use Muriotic acid mixed with hydrogen Peroxide which is about as cheap as you can get for an etchant (about $10 a Gallon) and it works very fast and works great......

[Paul Perry (Frostwave)]

"The principal danger from formic acid is from skin or eye contact with liquid formic acid or with the concentrated vapors. Any of these exposure routes can cause severe chemical burns, and eye exposure can result in permanent eye damage. Inhaled vapors may similarly cause irritation or burns in the respiratory tract. Since carbon monoxide may also be present in formic acid vapors, care should be taken wherever large quantities of formic acid fumes are present. The US OSHA Permissible Exposure Level (PEL) of formic acid vapor in the work environment is 5 parts per million parts of air (ppm)."

In short, I wouldn't go anywhere near it. And I don't scare easily.. it's a good deal nastier than hydrochloric.

[jpm83]

Thanks for the replies. I was asking because here in Finland that stuff is used for preserving live stock food (grass). And  I think that My relatives whitch have given up farming could have that stuff somewhere. But now that I think of it, that stuff could be even too strong for etching PCBs. Just remembered that one guy had accidently stepped in that stuff and the skin at the bottom of his feet was pealed off.

Janne

[modsquad]

Well, there ya go.

[jakenold]

The best way I found for etching is first etching the boards with the electrolysis-technique. That usually gets the most of it. Then you can remove the last with some mild sodiumnitrate. That's really mild, so you can stick your hands down and pick the boards up - just remember to wash them afterwards. That's what I do, and I've never had my fingers burned, miscolored or etched 

Jake

[jakenold]

Oh yeah, and you save money as all you need is water, power and salt, it's easy to dispose of, it's very safe and it's FUN to look at! Impress your friends! 

Jake