I have only ever used ferric chloride and like Hero says it is messy but it works well. I have etched some pretty small footprints before. It's not too bad if you take precautions like protecting counter tops, wearing rubber gloves, etc. I usually heat up the etching solution beforehand by submerging the entire sealed bottle into hot water. Then I put the board to be etched in a plastic container and pour the etchant over it. I then agitate the container by rocking it gently back and forth while holding it over a lightbulb as a heat souce. Just don't put your face directly over it because it's kind of nasty stuff. Also, never spill it on your carpet like I did because you won't get it out. I can't wait until I move out of my apartment and see how much $ they are going to take out of my deposit for that.
Let me get this straight Boncuk, you are telling me I can remove FeCl stains with plain old SALTWATER!!! That's awesome! I should have payed more attention in chemistry class. I'm going to try that as soon as I get home. I've tried many off the shelf cleaners and all I've succeeded in doing so far was spreading the stain around. I guess it doesn't help that it's a light colored carpet. I'll let you know how things turn out. If it works, I'll start petitioning to officialy rename saltwater to "Boncuk Juice".
Dan,
Even if the Boncuk Juice works, I'm going to stick with my original recommendation of not spilling any FeCl to begin with.
EDIT: I know all you guys with thousands of posts will probably laugh at this but, it's my 500th post. Yay!
I would say that sodium persulphate is neither better nor worse than ferric chloride, it's just a different material with different properties; each has its advantages and disadvantages.
I've got a large container of sodium persulphate, I know it doesn't keep very long once diluted so I only make up as much as I need. It's slow but I'm never in any great rush so that doesn't matter. I've only ever used ferric chloride at school and college and it does etch well and keeps for ages once diluted but it's really messy.
If you have an area in your home or workshop you don't mind getting messed up and wear old clothes when etching then I'd recommend ferric chloride, but it you want to etch in your kitchen then I'd recommend clean sodium persulphate any day.
Once the stain has set (dried) it's likely permanent. From what little I know I like the Ferric Chrloride method better, but that's primarily because I know where to dispose of the wastes it generates, not just safely, but beneficially to both parties.
I could be wrong, and for the sake of any stains you may have I do hope so as well => Depends a LOT on the material it got on/into weather or not it's simply a surface discoloration or weather or not it actually soaked into/chemically altered the material.
As far as disposal goes I used to work at a Metal finishing plant and I know the owner. Ferric Chloride is often used in the waste treatment process because it adds weight to some of the smaller suspended solids making the floc bigger and getting more of the heavy metals they need to remove out, so they get some free ferric chloride to help with the floc formation and the added copper will fall right out into their waste treatment stream adding neglible metal contenet and it's then turned into a sludge dewatered and dried into something that looks much like common dirt but with a decent amount of heavy metals and shipped off to a hazardous waste dispsoal site. I guess typically what they do is mix it with concrete to makme it harder for it to leach out into ground water and then it goes to special dumps rated for hazardous waste, all nice and legal like.
Let me get this straight Boncuk, you are telling me I can remove FeCl stains with plain old SALTWATER!!! That's awesome! I should have payed more attention in chemistry class. I'm going to try that as soon as I get home. I've tried many off the shelf cleaners and all I've succeeded in doing so far was spreading the stain around. I guess it doesn't help that it's a light colored carpet. I'll let you know how things turn out. If it works, I'll start petitioning to officialy rename saltwater to "Boncuk Juice".
I suggest to taste NaCl for a quick test. I doubt it will taste salty, but I'm sure it will bite your tongue. .
As a matter of fact natriumchloride is also used to produce soap.
It should at least do something to the spots on the carpet. I never use gloves when etching a board and my fingers, especially the finger nails turn brown. Using natriumchloride and washing my hands with the solution the brown colour disappears rapidly, burning the fingers a bit.
As an alternative you might try TESCO LOTUS bathroom cleaner (violet plastic bottle). I dissolves organic stuff without leftover.
(Saves funeral expenses as well. )
Applying some vaseline the fingers look like new.
If it does something good to your carpet you might go ahead and call it "Boncuk Juice".
I suggest to taste NaCl for a quick test. I doubt it will taste salty, but I'm sure it will bite your tongue. .
As a matter of fact natriumchloride is also used to produce soap.]
Isn't NaCl what the ancient Egyptians used to mummify bodies? A mixture of Baking soda and Salt?
I'm not sure if it was used to mummify people or not but NaCl is just plain old salt. Baking soda is Sodium Bicarbonate or NaHCO3. Despite that fact, hopefully it will soon be used to clean my carpet. Sorry Boncuk, I've been working nights and haven't had a chance to try it yet. I will soon!