Mulberry Elkington - Briefcase water stain from the inside.

>>> I suppose the leather of the bag is vegetable oil tanned leather.

Vegetable-tanned leather is more pH sensitive than the softer chrome-tanned leathers.
It’s the pH value of the water that is the main cause that has affected the leather constituents including dyestuff to break the hydrogen bonding and migrate forming the darker outer ring.

>>> I would like to know if the stains are removable.

This migrating stain is removable. Plan A is to use Hydrator-3.3 and Plan B is to use Vachetta-2.8.

Hydrator-3.3 as phase 1 removes the stain by moving, redistributing, wicking, protonating and reactivating process. It will cause the least effect in overall appearance.
Some features of Hydrator-3.3 includes the followings:

c) To redistribute the leather constituents from surrounding areas.
d) To activate the dormant dyestuff within the leather structure for color refreshing.
e) To facilitates colloidal water movement within the inter-fibrillary spaces for wicking foreign soiling particulates to resurface.
f) To stabilize, pH balance and charge the protein fiber below its iso-electric point (pI) ionic positive to hydrogen bond with the ionic negative fatliquor more effectively.

Technique is to saturate the thickness of the entire section of the leather up to 72 hours by “reverse transfer” with control evaporation for effective result.

Vachetta-2.8 as phase 2 takes care of stubborn remaining stains if any and inspect when dry for satisfaction. Any drastic difference in appearance has to be address by blending in the entire bag to match.

Degreaser-2.2 as phase 3 takes care of oil, grease and sweat stains if any follows with Acidifier-2.0 to rinse off suspended soiling.

The above 3 process takes care of the localized stains as well as feathering out the entire bag where necessary to give an overall appearance.

Besides appearance the leather integrity for suppleness with softness and strength has to be taken care for to prevent stiffness that may lead to premature cracks. This is done with Hydrator-3.3 > Fatliquor-5.0 > Hydrator-3.3 system.

Finishes protection is with option of choice with Protector-D or Protector-B+

Roger Koh
Leather Care Consultant
www.LeatherDoctor.com
[email protected]

Products mentioned are found in this Kit V4, Protector-B+ may be an option instead of Protector-D

Attachment 3354
Leather Doctor® Kit V4 – Vachetta Leather Body Oil, Grease and Sweat / Browning Removal Kit
Leather Doctor® Kit V4 specialty problem solving kit include Vachetta-2.8 for browning removal and Degreaser-2.2 for body contact decontamination systems in a holistic approach. Kit V4 is a combination kit from Kit V3 and Kit V5.dr without duplicating of products for these common related problems. Darkening appearance from body contact and browning from liquid stain are two main inevitable common problems associated with naked unfinished vachetta leathers. Leather being absorbent absorb and accumulates body moisture from contact and when neglected resulted in a darkening appearance. Besides appearance the sweat with traces of urea may cause the protein fiber from shifting ionic negative (-ve) manifesting as tackiness and reverting to rawhide. Degreaser-2.2 solves the darkening effect by penetrating, lubricating and suspending the soiling particulates and simultaneously protonate the protein fiber ionic positive (+ve). The amphoteric protein fiber is further rinse and ionic positive (+ve) charge with Acidifier-2.0 to strengthen the ionic attraction between its other non-amphoteric ionic negative (-ve) leather constituents like the tanning agent and the fatliquor. This dual duty removes the unwanted soiling particulates and pH balance the pH chemistry integrity of the leather at the same time. Browning of vachetta leathers is associated with alkaline over-exposure, vachetta being a lower pH value than most other tanned leathers averages pH 4 is more sensitive to alkaline cleaning or stains and even water at pH 7 will cause discoloration and browning.Vachetta-2.8 with its low pH works by oxidation-reduction reaction to reduce the discoloration or browning effect to a more even appearance when the leather is left to dry naturally. Leather rejuvenating is mandatory and comes next when appearance become satisfactorily. This is accomplished with Hydrator-3.3 > Fatliquor-5.0 system. Hydrator-3.3 plays a significant role in absorbent leathers like vachetta where stains are usually penetrated. The hydrator’s surfactancy helps internal leather structure colloidal movement by moving suspended soiling particulates to the surface at each wicking process until exhausted and is often used as part of the rinsing process. Besides hydrator is used to check for surface tension and relax the leather fiber prior to ionic negative (-ve) charged Fatliquor-5.0 replenishing. Natural slow drying in between application until saturation produces a softer leather. Protecting the leather with Protector-D impart a natural draggy-feel and reduces wear to the grain of the leather, conceal scuff with its healing properties that also allows transpiration to take place or breaths naturally. Note that the mentioned products suffix numbers denotes its pH value in this holistic approach to removing the common problems associated with vachetta, saddlery and veg-tan leathers.