doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com FeCl.....a technical question

'Thanks' to our own Chuck H, I recently found some ferric chloride solution in quantity - and am about to embark on coloring composite steel. More correctly, learning to color.....

My question to those of you here successfully doing this is 'how long' does your 15% FeCl seem to last from job to job before having to replace it? I have a 3" I.D. capped, pvc pipe that holds right at one gallon of solution. I plan on only a 5-10 sec. maximum immersion with bores/etc. plugged, but still the stuff can't last forever. Any experiences shared are appreciated.

Rob Harris

FeCl3 reacts with the iron in the barrels and the rust by moving electrons.The Fe is in the +3 state and will snare one electron per atom and become Fe in the +2 state. So, how long will this take? It all depends on how much etching is going on. In your case, not very many barrels, as the iron and rust have a lot of electrons to furnish and your gallon has a limited number of electrons to take .It is possible to regenerate the FeCl3 from the FeCl2 that was generated,but that is dangerous chemistry.So, as the process slows to nothing,time to replace.

William,

'Thanks' - as that makes sense even to me. My intent is to do perhaps a set or two a year, and am also wondering about the long-term storage of FeCl3 inside a PVC container. May be best to start with a fresh batch each time for the couple of sets I hope to do, and evaluate from there for efficacy.

Much appreciated,

Rob

Robert - if your goal is to conserve your solution, you can brush it on with one of those little sponge brushes. You then work the solution with 0000 steel wool. Works fine.

eeb,

Sounds like a practical way of doing it.....which gets me to thinking why a fine-mist spray bottle of FeCl3 (15%) wouldn't also work for providing a rapid, uniform application.

With short application time being the goal, a fine mist of the stuff delivered with a few squirts may possibly coat it as quickly as brushing before removal with 0000 wool. Five to ten seconds dwell time at 15% strength, possibly 15-30 seconds at weaker strengths, seems to be the accepted norm here and I was pondering whether a spray application might work just as well. Just a thought. In any event, will try your foam brush technique when practicing.....and 'Thanks' for your input.

Rob

I'd be more comfy using eeb's method if the solution was weaker. But hey, the stuff is cheap enough that it's not a problem for me to use a dip batch once and toss it. I do barrels so seldom, I couldn't justify keeping solution.

Good point, Chuck, and 'Thanks' to you guys for your help.


Rob

Chuck - I dilute the solution 50/50 with distilled water, which I think is around 12%. I work with it pretty fast.

I am a Pharmacist , and have a fair amount of Chemistry experience also. (Not as much as Mr. Apperson tho). I do not see any need to do the dipping method vs the brushing on. I have done quite a few barrels using FeCL4 as an etch to bring out contrast and I use a medium stiff brush and about a 7-8% soln which works great. About 30 seconds to a minute of wetness and then fine wet steel to scrub off the excess stuff.

Thanks also, Leighton. I kinda like the idea of the weaker solution with its slightly longer standing time vs. the 15% soln.

Hate feeling rushed when applying something.....must come from a bad glue job experience or three!

Will be giving these ideas a try to see what works best for me.

All Best,

Rob