Mold Or Hard Water Stain?

[Roger J]

NOOOOOOOOO!

This quarter sized stain developed in only five hours.

I was wetforming some 8 ounce veg, so the leather was saturated with water, and was held in place with a weighted down piece of plastic covered plywood.

Realistically, can oxalic acid work on such a bad stain (I'd have to order it), or should I just dye the thing black?

[gainesvilleman]

You might try in the future to use oxalic acid prior to any work on the leather, It would not hurt to use it on this leather before you go any further. Good luck.

[Troy I]

Instead of ordering Oxalic acid...try Barkeepers Friend...you can find this at Lowes, Home Depot etc. I've used this with very good results. I mix it with water and then scrub with an old rag. The main ingredient in Barkeepers Friend is Oxalic acid. The cost is about $2.00 for a 21 oz can. Good luck.

[camano ridge]

It looks like the leather may of come in contact with metal or metal shavings.

[Roger J]

Thanks for the Barkeepers Friend suggestion, I'll pick some up tonight on the way home.

It looks like the leather may of come in contact with metal or metal shavings.

I did dust off the leather beforhand, but probably not the piece of plywood used to weight it down...d'oh!

[Sona]

I did dust off the leather beforhand, but probably not the piece of plywood used to weight it down...d'oh!

The problem with metal is that it needs nearly nothing to react with water. So even if you dust it of it might be that there are some metal fragments left behind in the pores or sth like that. And you won´t see them until they react with water.

IF this is the result of some metal stuff, you sadly won´t get it out. So I just hope for you, that it´s sth different....

[Roger J]

Thanks Sona, all I can say is my lesson is learned!

Last night I picked up some Barkeepers Friend, and went to the pharmacy to see if they had OA. Discovered that the common name for OA is "Salts of Lemon"...which I had at home!

Since the damage was done, I decided to try a bunch of solutions on different spots. Vineger, diluted laundry bleach, and rubbing alcohal did nothing at all.

OA, mixed in 1 teaspoon per pint ratio, worked the best.

Barkeepers' Friend (which is 1/10 OA), was mixed with a 10 teaspoon per pint ratio, didn't work as well as OA.

Lemon juice worked only on light stuff.

I used a toothpick to stroke the solutions on. Repeated every 15 minutes, 3 times total. The first picture is the untouched stain, the second is right after the last application of the solutions (while still wet), and the third is after it dried (before it was rinsed off)

sorry for the picture quality.

I'll do a final cleaning tonight.

Edited March 4, 2014 by Roger J

[camano ridge]

Thee lemon juice is what I normasly use if I have to deal with metal spots. Any of those three should work however you will need to apply with a rag or sponge wetted with your choice and rub a bit . Stay away from the vinegar. Metal shaving and vinegar are what is used to create vinegaroon also called vinegar black and is used in place of black dye.

Edited March 4, 2014 by camano ridge

[Northmount]

Iron and the tannin in the leather makes black. Take away one or the other and it won't turn black. So for veg tanned leather, you have to keep all sources of iron contamination away from it while wet/damp. (Normal stamping with steel tools normally won't produce black spots.)

Vinegar is dilute acetic acid. It will not produce black in leather anymore than oxalic acid will.

But once you dissolve iron in the vinegar, that is a whole different story. Now it contains iron and will react with the tannin in the leather. When you add enough iron to the vinegar, all the acid is used up and the vinegar smell is mostly gone. Many people use "vinegaroon" to their advantage to get a nice solid black that doesn't bleed and may color the leather from one side to the other depending on how you apply it.

Tom

[Roger J]

Thanks for the vinegaroon information, it is something I really want to try someday. Had I had some on hand, it is probably what I would have used to cover-up this stain.

****

Here is a picture of the final clean-up. There is still a bit of a shading effect, but once it is oiled-up it should be practically invisible. I'm really super happy with the results and I really want to thank all the folks that helped.

It took three applications of the solution (with a Q-tip) waiting about 20 minutes between each coat for the stain to disappear. It wasn't strong enough to get it in one shot, but I prefered going slow.

Question:

Should one neutralize the OA with a solution of water and baking soda? I just wiped down the area with water a few times and am wondering if it is enough?

[Northmount]

Looking good!

I've only rinsed off the surface. Had no problems after. It is a fairly weak acid so gets "used up" quickly.

I occasionally treat pieces of leather that don't have an even colour. It usually helps.

Tom

[oltoot]

I never do but I often do oil to replace what the OA seems to take out. Lexol Nf most of the time

[Roger J]

Thanks guys.

I must have rinsed too well, and the metal particles must be deeply imbedded in the leather because 24 hours later, a slight greyish spotting reappeared in the main area (it was still fine after 12 hours).

I just reapplied the some OA and will leave it alone this time to see what happens.

[Roger J]

It seems to be fine now (48 hours latter)