doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Zinc Ammonia brown

Does anyone use this rust solution ?
I'm wondering if it keeps well, I've been given some large reagent jars with good lids so could mix up a good quantity of it but have no idea if it's one to store or make up as and when you need it.
Thanks,
Nick.

Always tempting when one has a nice container but generally speaking I suspect such solutions, unlike typical industrial solutions like acids, are better mixed up as needed. As a rule solutions do not age well and there's the simple physical reality that solutions are more prone to accidents than solids. Would it really be that worth while to pre-mix? I tend to keep solids as such until needed unless something takes a hell of a long time to disolve to saturation. Not an answer to your question per se but something to consider.
Jeremy

Thanks Jeremy, I see your point about storing liquids. I tend to buy my chemicals in ounce or half ounce amounts, the zinc chloride I have has absorbed moisture from the air and turned to mush, there's enough to make half a gallon so thought I may aswell make it all up rather than trying to dry it as much as possible then try and guess the weights including the water in it. I'll probably get some new dry stuff and treble bag it inside a sealed jar with some silica gel in and make it up as I need it. It'll most likely be for small parts as it's reputed to black with one pass and a neutralise so it's not a life or death decision whether I make a big batch or not.
Thanks,
Nick.

Zinc Ammonium (Chloride ?),,that's used in the galvanizing process as a prep dip before the zinc coating is applied. Never heard of it used for bbl browning,,doesn't mean it can't work!

Zinc Chloride is a rapid rusting agent,,it's a common soft solder flux,,most commonly called 'acid flux'. It will rust and keep on rusting for you unless thoroughly washed from the surface.

Ammonium Chloride , used to commonly be called Sal-Ammoniac in block form for soft soldering, Water soluable and very good rusting agent for bbl browning. You can still buy it as SalAmmoniac. Works well as a flux when melting scrap gold or silver ect to remove the trace metals.

Never tried the first one,,but the next 2 work fine. Neither will go bad if mixed in a soln and left on the shelf. Might rust through a tin jar cap though! Plastic works best I've found.

Hi Kutter, I've not tried it myself yet , should be next week before I get around to it. The mix is from page 70 in Angiers, it's his own composition and it says...

Zinc Chloride anh 137 grs
Ammonium Chloride 91 grs
Hydrochloric Acid D 1.16 46 grs
Water t.s. to make 1/4 U.S. pt

"This browne is fairly rapid acting and gives a very fine , deep black on both soft and hard steel with a single rusting. Neutralisation required."

Sounds as if it's worth a try. I should have written Zinc Ammonium browne sorry, may have been misleading. I imagine it could be quite aggressive so will run some trials. This mix is to replace (and to save having to use) C.28 from the same book. Small parts can be prepped, then dunked into this mix for a second or so and as long as it's dried quick is more often than not ready to boil off after 3 or 4 hours giving a good deep black with the minimum of surface change in one go. I add some washing soda to the last boil after everything is carded out of habit but this mix shouldn't after rust, just a shame it contains Hg. I don't want to use that unless necessary so thought the Zinc Ammonium mix could make a good replacement.

Sounds interesting!,,Let us know how the results come out.
Lots of stuff in it to make steel rust that's for sure.