Making your own etching liquid

[Glassical Jazz]

Hi all
I bought some ammonium hydrofluoride crystals, which is the ingredient in the etching liquid, and thoroughly dissolved them with boiling water that I thought was to the right proportion. It is etching my beads, but instead of a satin finish, I find it kind of rough. I have tried anywhere from 1 min on up. I usually only etch for 2 mins and get a real nice smooth etch. Does anyone out there make their own, and what proportions do you use, or in other words what the heck have I done wrong?:confused:

[Kalera]

I have tried it before and never got a satisfactory etch. I sent it back to the lab from whence it came because it made me really uncomfortable having something that incredibly poisonous in a house with children. I hope you won't mind the warning, as you probably already know, but please be VERY VERY CAREFUL with that stuff, as it is absorbed through your skin and even small exposures can lead to permanent severe bone damage.

[RSimmons]

Be really careful getting that stuff hot. Ammonium fluoride will release hydrogen fluoride gas (hydrofluoric acid) when you heat it very much. We're talking extreme toxicity here. Don't do it in you kitchen or anywhere that you don't have truly superior ventilation. I'd recommend not doing it at all.

Robert

[Kalera]

Yes, it should never be heated. You can dissolve it in warm tap water... but, I have to second what Robert said. When I experimented with it I did so under the supervision of a chemist... but all told I think it is best left alone. Especially since the damage it can do to you can be initially painless but ultimately terrible and untreatable.

[RSimmons]

Calcium alginate injections at the site of HF exposure fall into the category of 'Not Fun.' Pulmonary exposure takes it to another level.

R

[SteveWright]

You have to use care when using the solution, I've used the commercial version for years without incident. I use eye and skin protection and am careful.

The crystal form is a bit scary. I would not handle the crystals personally unless I had a fume hood. Inhaling the dust can't be good. A boiling pot of hydrofluoric acid takes me back to horror movies from the late 50's where being dissolved in a vat of boiling acid was brought to the big screen in House on Haunted Hill.

Yikes. I hope you did not make gallons of the stuff. The real question now is, Now what do I do with the stuff?

Steve

[KEW]

I never get the beautiful smooth results that others get from the commercial solutions. Mine always look crude and rough. I very rarely etch anymore and am considering getting a tumbler.

[Kevan]

The ingredient in Etch All is ammonium bifluoride. It isn't the same as hydrofluoric acid.

Hydrofluoric acid can eat your bones through your skin. It's very dangerous.

[houptdavid]

Study up on it!
http://enews.heywoodenamels.com/V1_No5_March_2002/eNAMEL_hydrofluoric_acid.html
http://nj.gov/health/eoh/rtkweb/documents/fs/0089.pdf


The use of (dry) Ammonium Bifluoride as a "safe" replacement for hydrofluoric acid is a unsafe practice. The unitiated person who judges this as "safe" can quickly get into trouble since once the Ammoniuim Bifluoride (NH4F)HF is contacted with water, it will decompose to Ammonium Fluoride, NH4F and hydrofluoric acid ,HF. The HF content of the resulting solution will be ~ 33% of the original Ammonium Bifluoride and; if at the salt's solubility limit of ~ 40%, the HF content will be ~ 13%. . . very corrosive, toxic and hazardous.

Some folks have used Ammonium Bifluoride as a substitute for HF and created (what they refer to as ) a "acid free" wheel cleaner. A dangerous and deceptive practice.

[volkanokaren]

Excellent description Kevan,straight to the point.
Chemicals are not really something to "play" with.
Heating them intensifies and causes health problems.

Karen
Volkano Exotik

ripzz