White deposits on leather

[Ferryman]

Just pulled an old wallets (10 year old) out of the draw and when I opened it there was a white powdery deposit on the surfaces.

I managed to clean it all off using some car leather upholstery cleaner, but just wondered what caused the white deposit. (it was dry stored in the house)

[Constabulary]

It may be grease or wax from an "overtreated" leather. Grease or wax sometimes "sweats" out when the temperatures are changing or humidity changes. Over the years I had this on some military M-1916 holsters for the Colt 1911 from the WWII and WWII era. Even when you removed it - it may come back.

if it is no mold and when you apply heat (hair dryer) it most likely will diapers but may come back one day. Mold will stay as is when you apply heat.

Just my experience.

Edited April 11, 2021 by Constabulary

[SaintJoy18]

Not to be gross, but it could also have been salts, especially if it was a men's wallet. Salt from "butt sweat" could have remained in the leather and as the oils dried out over the years the salts leached out onto the surface. Just a theory

[ScottWolf]

5 hours ago, Ferryman said:

Just pulled an old wallets (10 year old) out of the draw and when I opened it there was a white powdery deposit on the surfaces.

I managed to clean it all off using some car leather upholstery cleaner, but just wondered what caused the white deposit. (it was dry stored in the house)

I've seen this attributed to neatsfoot oil in old leather tanning text, as well as had items exhibit the same white film that you have. From na article titled: "The Application of Oils and Greases to leather", page 102

 

page 102: "oils such as noatsfoot opinions differ widely. Neatsfoot oil is

a very common one in England as a material for use with fine

leathers, but Eitner warns against its use on the ground that it

is liable to cause a white spue and also to give the leather a

disagreeable smell."

 

 

 

page 117: "The defect above mentioned of the skins when in a warehouse

throwing off a white spue or deposit on the grain surface,

particularly noticeable on black leathers, is chiefly due to this

cause, the acid in the skins causing the neatsfoot oil and soap

fat liquor to spue."

Edited April 11, 2021 by ScottWolf