Vinegaroon Uniformity

[jhinaz]

My previous experience with vinegaroon is quite limited but I have many pages of information that I got from searching the subject on this forum. I used that information to vinegaroon a belt about 2 years ago and it turned out very well.

Using that same information today I vinegarooned a 7-8 oz belt blank (which was stamped and burnished prior to vinegarooning) as a test case before I did a 'wallet-size' piece of 7-8 oz leather (which also was burnished and stamped before vinegarooning....albeit a different pattern from that on the belt blank). The veg-tanned leathers were from different cows but the vinegaroon process started out being the same for both pieces, with the wallet-piece being started right after I completed the 'final rinse' on the belt.

Both were soaked thoroughly in a strong black tea and then soaked in vinegaroon; rinsed in baking soda and then a clean water rinse.

When I removed the wallet-size piece from the vinegaroon the basketweave stamping was a uniform, dark, deep, black but I could still see 'brown' around the border stamping, so I re-soaked the wallet-piece in the black tea and then again into the vinegaroon. The trouble area MAY have gotten a little blacker but I could still see 'brown' around the border stamping. I let it rest for 30 minutes and the trouble area MAY have gotten a little blacker but I still could see 'brown' around the border stamping. I decided to proceed with the baking soda wash, rinsed it in fresh water, and when the leather was drier (but still damp) I oiled it with Neats Foot oil. When it had dried I applied a 2nd coat of NF oil.

Again, the trouble area MAY have gotten a little blacker but I can STILL see 'brown' around the border stamping.

Could it be that the D435 border stamp that I used burnished or 'sealed' the leather around it so it does not accept the vinegaroon readily?

Does anyone have any suggestions as to what I should do now that the piece has been oiled but not sealed?

Thank you for your comments and suggestions. - John

[mlapaglia]

Set it aside for a few days. Vinegeroon is a chemical reaction and it should get black but may take a while due to the compressed leather area. Ive even vinegrooned pieces that were coated on the grain side. It just took a while for the reaction to make it all the way through. The rinse you did will not totally cancle the reaction. It should get there.

[jhinaz]

I've been out of town (away from a computer) since I posted the above question and have just had the opportunity to read your reply.....thanks for your suggestion mlapaglia.

It's been four days since I applied the vinegaroon and the 'problem area' still shows some brown around the border stamping.

I'm hoping there's a solution to my problem which doesn't involve using dye, but as last resort I can cover that area with black dye.

The only thing that I did different between 'preping' the belt blank and 'preping' the wallet-piece was I rubbed the grain side of the wallet-piece with a glass burnisher. I wonder if the burnisher AND the Border stamp compressed the surface grain too much to accept the vinegaroon???? - John

[jhinaz]

I did a vinegaroon do-over of JUST the 'problem area' and it appears to be okay now.

I used a wool applicator to apply a deglazer, then strong-tea followed by vinegaroon to just the border depressions (allowing it to lay in the 'channel'). There was no visable change after the vinegaroon layed in the depression for 3 minutes so I reapplied it for another 3 minutes (6 minutes total) before it turned the brown area to black. I dipped the entire piece in a baking soda wash for 30 seconds and then a fresh water rinse....I hope the additional BS wash didn't upset the ph too much, but it is what it is. - John

[mlapaglia]

Glad you here you got it fixed. Good idea. Ph will be fine.

[TwinOaks]

The fact that the 'roon worked for both pieces indicates that the issue is with the leather. There are all kinds of factors that could contribute to the lack of reaction - finger prints are right up at the top of the list.....so is oil residue left on the swivel knife blade, or residue from the strop that's on the blade, or something on the paper used to transfer the pattern to the leather.....a pretty long list, really........and there's nothing to say that YOU contributed at all. It could simply be where something was laid on the leather at the distributor or tannery. You can eliminate many of the issues by cleaning the leather with alcohol or oxalic acid.

For a LONG time, I presumed the leather was good to go, and would deal with any little problems as they popped up. Then I figured out that taking the longer route, and following a procedure of cleaning the leather, wearing sleeves and gloves, wiping off tools.....yada, yada, yada.......only SEEMS longer but it gets rid of all the problems that take additional time to repair.

[jhinaz]

Thanks for replying to my question concerning uniformity, TwinOaks. Those yada, yada, yada's can present a LOT of problems can't they?

I'll probably never know what the problem was with this piece of leather, which is OK with me now that the original problem has been corrected. It just seems strange to me that different 'portions' of three border areas (out of 4.....and not the entire length of any border area) were affected while none of the basket stamping was affected. I'll just store this experience away in the yada-yada-yada locker for future reference. - John

Edited October 13, 2012 by jhinaz

[shtoink]

I would argue that the amount of oils deposited from fingers or directly from the blade is negligible compared to the application of neatsfoot oil, but I don't think that that was the cause of the problem.

I started to thin in this one and reread the original post and the input that everyone had. I ended up doing a bit of research on what exactly is going on when your use vinegaroon to see if there is anything that wasn't covered already in the information here on the forum. I won't go into all the dreadfully boring details, but my theory is a bit different and a solution is pretty straight forward.

What I gathered is that the leather was compressed heavily is places with either a pear shader or beveler. I assumed it to be smooth, though a texture was not specified. These were described as the problem areas where the blackening of the leather did not occur.

Keeping the above in mind, blackening leather with vinegaroon is a chemical reaction and the the level of acetic acid in vinegar in only around 5% by volume. That translates into quite a bit of water, a small of iron(II) acetate, rust, hydrogen gas, and whatever was on the metal you dropped into it. The iron(II) acetate is the only thing we want, which is what is reacting with the tannins to produce the black color. Since the actual amount of acetate is small, the reaction can be slow.

Now that that is out of the way, it's on to my theory. The reaction is already a relatively slow one compounded by the compressed fibers in the leather. Now, take into account that iron(II) acetate is enormous compared to the water it's contained within. The acetate is roughly 10 times the mass of water. The iron(II) acetate is most likely having a hard time making into leather in order to produce the desired reaction and that it may have eventually reacted and turned those areas black if given time. It's like the acetate molecules are like cars trying to get though a tollbooth in the peak of rush hour. It will eventually happen, just very very slowly.

As a final note, this is just a theory and I was only able to go by the information made available. There is still a possibility that I am completely wrong, so don't take it as gospel. Also, I am glad that the persistence payed off and you were able to fix the issue with added applications in the end.

[TwinOaks]

That theory does have some validity, but fails to address that the basket stamping was effected differently than the border. Typically a border is done with a camouflage tool. While it may be a little bit tighter pattern, it is anything but a uniform compression of the fibers. Also, the leather fibers are themselves much larger than the Fe(C2H3O2)2 molecules. I think the issue is not so much that the fibers are compressed to the point that the Fe(C2H3O2)2 can't penetrate, but that something, perhaps compression or slicking/burnishing, is preventing the WATER molecules from carrying the Fe(C2H3O2)2 to the tannins in the fibers.

In my experiences with the 'roon, I've had leather turn brown, light gray, a beautiful shade of 'midnight blue' (I think that was some ZW leather), and a horrendous green that looked like a product of Linda Blair*.....and black of course. Reaction time varies on the acidity of the solution. In batches that still smell strongly of vinegar the reaction was nearly instantaneous - which may be a product of the penetrating ability of the carrier - and in old batches that have almost no smell, it takes up to a minute. I typically brush it on with a 1" nylon brush, but still soak it if needed. Another factor in the shading is the purity of the solution. In batches where I've strained/filtered the 'roon, I've had fewer problems. In my current batch, which is still sitting on the back porch in a 1 gal. pickle jar, getting the rust stirred up on the bottom results in some ugly patches. Speaking of rust, there's some probability that the brown is caused by solubilized (read as "itty bitty and floating in the solution") rust particles sticking to the surface of the leather. When I encounter them (yes, because I was too lazy to filter the brew), I just have to wipe the leather down with a damp rag and apply some 'clean' solution.

There is a site (leatherchemists.org) that deals with the uberfun chemistry of all things leather.....but I don't go there because I didn't enjoy chemistry class beyond "hey, watch thi.......". THEY could certainly give an accurate answer if anyone wanted to delve that far into it.

Note: The 'Linda Blair green' color was the result of leaving a wool dauber.....specifically the zinc coated dauber handle....sitting in a sealed jar of 'roon. I had set up a mini work area at my friend's store, and left it there for a few weeks. Being acidic, the 'roon ate part of the handle and the zinc reacted with it. If anyone is trying for a color that just screams "left in the barn to mildew"....this is the way to get it.