Green jell like mold on leather getting rid of it!

[mantaleather]

 In anyone's experience have you eve found a green jell like substance usually between leather and conchas or if conchas screwed to the saddle in the hole or large clumps in the whole and under the leather conchas.

I have encountered it on several saddles some worse tan others. I have tried cleaning with vinegar, anti mold solution, brass brushes. It seems to always come back.

I'm restoring a saddle right now that has had it repeat 3 times in 5 years. This time was the worst.Any help or direction would be of great help

Thanks Mike

[battlemunky]

Its corrosion. You will never stop it only limit it/clean it. The metals in the concho react with the salts in the leather when moisture is present, even humidity. Vinegar likely makes it occur faster. Oiling it may help keep it at bay. Try some baking soda/water solution to stop the reaction and then once it is thoroughly rinsed and dried, oil it with NFO or olive oil to help stop/slow the reaction over time.

[Matt S]

3 hours ago, battlemunky said:

Its corrosion. You will never stop it only limit it/clean it. The metals in the concho react with the salts in the leather when moisture is present, even humidity. Vinegar likely makes it occur faster. Oiling it may help keep it at bay. Try some baking soda/water solution to stop the reaction and then once it is thoroughly rinsed and dried, oil it with NFO or olive oil to help stop/slow the reaction over time.

Absolutely agree except for one minor point: I believe that the Verdigris corrosion is the salt, formed by the reaction of the copper in the rivet and the leather, which is slightly acidic, under moist conditions. (metal + acid => salt + H2). I'm not sure you'd want to add a basic solution (baking soda + water) as it'll increase the pH of the leather, leading to premature degradation. Veg tanned leather is/should be/"wants" to be slightly acidic -- usually somewhere around a pH of 4 IIRC. The green will be occurring more in the pockets around/under the conchos as those areas will hold water for longer in the event of a downpour or dunking, allowing the reaction to occur for longer.

Green stains around hardware indicate copper based (copper, brass or bronze) hardware. Black stains indicate iron (Steel) based hardware -- essentially the same reaction as vinegroon.

Not sure if verdigris is harmful to the leather or not. Cleaning might cause more harm than good.

It would be good to get some saddlers' opinions on this topic.

[kiwican]

50 minutes ago, Matt S said:

Absolutely agree except for one minor point: I believe that the Verdigris corrosion is the salt, formed by the reaction of the copper in the rivet and the leather, which is slightly acidic, under moist conditions. (metal + acid => salt + H2). I'm not sure you'd want to add a basic solution (baking soda + water) as it'll increase the pH of the leather, leading to premature degradation. Veg tanned leather is/should be/"wants" to be slightly acidic -- usually somewhere around a pH of 4 IIRC. The green will be occurring more in the pockets around/under the conchos as those areas will hold water for longer in the event of a downpour or dunking, allowing the reaction to occur for longer.

Green stains around hardware indicate copper based (copper, brass or bronze) hardware. Black stains indicate iron (Steel) based hardware -- essentially the same reaction as vinegroon.

Not sure if verdigris is harmful to the leather or not. Cleaning might cause more harm than good.

It would be good to get some saddlers' opinions on this topic.

Some pretty solid info here. Thanks 

[battlemunky]

Thanks for clarifying @Matt S!