Question about Vinegeroon

Sgt. C.J. Sabre · March 10, 2012, 10:37:34 AM

I originally posted this in the thread on old time dyes, but haven't gotten any answers. I figured I'd go ahead and ask it in it's own thread.
I started a batch of vinegeroon about two weeks ago. I aquired some steel dust from an auto parts store. It is from turning brakes. I'm using a gallon of vinegar, with the dust.
After two weeks, I'm still getting a nice froth in the bucket. How do I know when it's done? I presumed that when it is done, it would stop frothing.
It does a nice job blackening test pieces, but I want to make sure I do this right.

Thanks, Sgt. C.J. Sabred.

Mogorilla · March 10, 2012, 10:47:17 AM

If it is still frothing, the acid is still working on the steel. You getting the black because you do have a pretty good solution of Iron Acetate, but as long as it is frothing, acid is still working. Depending on your ratio fosteel dust to vinegar, you might run out of acetic acid before you run out of available iron in the steel. This is not a problem as the remaining steel will just be sludge at the bottom, you can decant the liquid and use it up. Actually I have wondered if letting the solution be iron heavy at the start would not help prevent people from damaging the leather with the acid, it would mean less baking soda required in the final dip as there would be little residual acid to neutralize. As a chemist, I would say let it go until it stops frothing, then decant if you have solids. Good luck.

Sgt. C.J. Sabre · March 11, 2012, 12:00:19 PM

Thanks Mogorilla. That's kind of what I was thinking.

Massive · March 13, 2012, 12:14:16 AM

can one throw the baking soda in the mix to get it neutral, if it was acid?

Cliff Fendley · March 13, 2012, 06:01:16 AM

I don't know what that would do, just keep adding steel until it wont take any more.

Mogorilla · March 13, 2012, 07:08:21 AM

Hi Cliff,
Probably not a good idea. By adding the baking soda, you are adding carbonate ions into the solution. The solution un-neutralized is positive Iron ions, negative acetate ions, hyrdonium ions (the acid) and negative acetate ions from the vinegar. I would have to dig through some books, but if ironcarbonate is less soluble than iron acetate, you would precipiate out your iron carbonate and ruin the vinegaroon. (I believe this is the case). I have duplicated vinegeroon by using ironacetate salt, water and a little vinegar. the addition of the vinegar gives it a buffering effect. It took 2 minutes of shaking as opposed to several weeks of letting it dissolve. I had access to the ironacetate when I was helping clean an old highschool lab, so not sure if any old individual can buy it or not.

ChuckBurrows · March 13, 2012, 12:36:16 PM

One when dissolving the iron IMO most people are not writing long enough or using enough iron - I keep adding iron until it starts to rust and doesn't really dissolve, then either decant or filter off the liquid keeping the lees for a new batch. THEN I leave the canister open to vent off any remaining gas (I was told by a chemist that acetic acid is highly volaile and gasses off quickly). Once NO or just a faint odor is left do I use it. Then use the baking soda dip (not too long or you'll burn the leather and that ain't good unless you like the crackelure look), followed by a coat of saddle oil both front and back, then hang in front of a fan or outside in the sun and breeze for at least 24 hours. Once all odor is gone, then and only then apply your final finish.
For those who prefer to speed things up you can get ferric nitrate crystals from the Science Co (they are on line out of Denver IIRC), no odor or waiting time and little to no residual acid - mix about 5 to 1 with water - otherwise do the same final process. FWIW - Ferric Nitrate (known in the past as Aqua Fortis at times) can also be documented for dying leather black in period.

ChurchandSon · March 13, 2012, 05:17:57 PM

Gentlemen, I don't fuss too much with mine. It's in a plastic coffee container with a couple of holes in the lid. At about half full I'll add some more Cider Vinegar and steel wool pads that get too small. I do a lot of filing and toss that in also. It's been going for about three years and kinda ugly in there but it works very well. I stir it up occasionally but that's about it.....Randy

Cliff Fendley · March 14, 2012, 05:29:20 PM

Quote from: Mogorilla on March 13, 2012, 07:08:21 AM
Hi Cliff,
Probably not a good idea. By adding the baking soda, you are adding carbonate ions into the solution. The solution un-neutralized is positive Iron ions, negative acetate ions, hyrdonium ions (the acid) and negative acetate ions from the vinegar. I would have to dig through some books, but if ironcarbonate is less soluble than iron acetate, you would precipiate out your iron carbonate and ruin the vinegaroon. (I believe this is the case). I have duplicated vinegeroon by using ironacetate salt, water and a little vinegar. the addition of the vinegar gives it a buffering effect. It took 2 minutes of shaking as opposed to several weeks of letting it dissolve. I had access to the ironacetate when I was helping clean an old highschool lab, so not sure if any old individual can buy it or not.

As Chuck said and as I said before, keep adding iron until it wont take any more. I don't have the scientific explanation for it but it works.

At some point it will start making a nasty layer of rust and doesn't eat any more iron. Pour off the liquid and let it air out. At this point it usually doesn't have that much odor anyway. I normally leave the lid loose while it's working.

Just do a search and do it the way Chuck say's to do it. I followed his methods and it work perfectly.

I've actually got a couple pieces of scrap that I first tried it on that I never bothered neutralizing in baking soda. I'm not sure how long it takes before any adverse effects will happen from the vinegaroon but those scrap pieces are still in fine shape and they've never been oiled or treated after dipping in the vinegaroon. The pieces are Wicket and Craig strap and carving leather.

Sgt. C.J. Sabre · March 14, 2012, 09:22:18 PM

Quote from: Cliff Fendley on March 14, 2012, 05:29:20 PM
As Chuck said and as I said before, keep adding iron until it wont take any more. I don't have the scientific explanation for it but it works.

At some point it will start making a nasty layer of rust and doesn't eat any more iron. Pour off the liquid and let it air out. At this point it usually doesn't have that much odor anyway. I normally leave the lid loose while it's working.

I'm starting to get a lot of rust on the sides of the bucket, (plastic), but still a lot of foaming, too. There's still dust in the bottom of the bucket, so I'm going to give it another couple weeks and see what happens.
Keep um coming, guys. Lots of good info here.

Massive · March 16, 2012, 01:10:11 AM

Does anyone know what the PH of the solution is?

Mogorilla · March 16, 2012, 06:53:55 AM

I am just doing some rough calculations in my head and logs aren't my strong suit, but for a reaction that has excess iron in it I would guess somewhere in the neighborhood of pH 5. Maybe a little higher.

G.W. Strong · April 02, 2012, 02:17:51 PM

I just started my first batch of Vinegaroon today. It is cooking along. How long before it begins to be useful?

ChuckBurrows · April 02, 2012, 04:28:20 PM

Quote from: Mogorilla on March 16, 2012, 06:53:55 AM
I am just doing some rough calculations in my head and logs aren't my strong suit, but for a reaction that has excess iron in it I would guess somewhere in the neighborhood of pH 5. Maybe a little higher.

4.5 - about the same as veg tanned leather

Sgt. C.J. Sabre · April 02, 2012, 08:20:51 PM

Quote from: Hopalong Strong on April 02, 2012, 02:17:51 PM
I just started my first batch of Vinegaroon today. It is cooking along. How long before it begins to be useful?

Mine is still reacting. I'm still getting a rusty colored froth on top. I have tested a few scraps, and it darkens them nicely. I suppose I could use it now, but I would have to make sure I neutralized it.
I'm going to wait until it stops reacting, and the vineger smell goes away to start using it.

Sgt. C.J. Sabre · April 04, 2012, 08:52:49 PM

Well guys, I think my first batch might be contaminated.

I checked it today, and when I stirred it to get rid of the froth, I had what looks like oil floating on it. I'm thinking that the brake turnings I got had oil on them.

So, back to square one. I'll get another gallon of vinager, and this time, some cheap steel wool to dissolve.
Here we go again!

ChuckBurrows · April 04, 2012, 10:30:46 PM

try it first before discarding - in over 40+ years using this stuff I've had lots of batches with that slick look and no problems..

Marshal Will Wingam · April 04, 2012, 11:25:39 PM

Mine looks like water that's been in a drain pan for a few years. Work fine, though.

ChurchandSon · April 05, 2012, 04:41:19 AM

Sgt. I agree with these fine fellows. Let it simmer for a while. My bucket resembles something out of a bad swamp movie and I've never been real particular about what kind of iron goes in it. I'm afraid to dump it out, I don't know what is living in the bottom.....Randy

And here's the color from that swamp water...

Cliff Fendley · April 05, 2012, 06:47:16 AM

C.J.

Even with steel wool take a torch to your metal source to make sure any oil is burned off. I'm not sure it matters or not but I do it anyway.

If it is oil on your current batch maybe you can skim it off the top. Mine gets a nasty crust on top I had to skim off anyway.