2004 Audi A4 Convertible Cabrio – Leather Stiffness from Water damaged.

>>> The seat dried the next day and is now very stiff, which of your products do you recommends to rehydrate the seat?

Hydrator-3.3 will help to relax the stiff leather back to place, it will then require the fatliquor to be replenished with Fatliquor-5.0 in this leather rejuvenating system.

This is pigment-finished leather and the finishes may resist the ingress of water or any other solution. Rainwater probably and logically collected on the concave seams, went under the finishes and moves up. Rainwater with a pH value higher than the pI of leather shift the amphoteric leather protein fiber ionic negative (-ve). Thus breaking the hydrogen bond between the leather protein fiber and the fatliquor leaches out. To get the fatliquor back to place is to first hydrate and relaxes and separate the stiff fiber preconditioning it prior to introducing Fatliquor-5.0 up to 14% of moisture content when dry will restore back the suppleness with softness and strength.

The practice and technique is to follow the rainwater path first with Hydrator-3.3. The entire affected area has to be work until the leather is plumps up. However, the compressed and wrinkled up finishes may already been delaminated from the leather crust and may not be able to be stretch back intact. The winkle surface is work under a plastic sheet to avoid further damages.

When the first phase of restoring the distortion back to place is satisfactorily, Fatliquor-5.0 is replenished following the path the Hydrator-3.3 takes.

Note:
What we are dealing is the leather structure and as long as we can hydrate it, we can soften it as soft as you wish back to the original. It is the percentage of fatliquor when dries that counts.

Roger Koh
Leather Care Consultant
[email protected]

Attachment 3480
Leather Doctor Kit At5.ws – Auto Leather Water Stain Removal Kit
Leather Doctor® Kit At5.ws, auto leather water-stain remover kit is design to remove water stains as the results of destabilizing the leather pH equilibrium. The side effect of alkaline overexposure manifests as marks and rings behaving like litmus paper. The darkening rings are leather constituents that breaks bond with the protein fiber and migrate forming the outer ring. Stains are clean with Clean-3.8 to remove surface residue prior to Acidifier-2.0. Acidifier-2.0 neutralizes the alkaline overexposure recharging the protein fiber ionic positive to re-attracts the ionic negative leather constituents. The leather is saturated and dwell up to 72 hours for extreme cases to facilitate redistribution and wicking up foreign contamination. A paper tissue covering without airspace helps trapped stains instead of remaining on the leather surface when dry. Hydrator-3.3 helps to redistributes the inter-fibrillary colloidal water movement; bringing the remaining stain to surface prior to fat and oil replenishing. Fatliquor-5.0 rejuvenates and imparts leather with softness and suppleness when dry. Protector-B+ enhances a non-stick rub-resistant protection with a buttery-feel that shield against sticky soiling. Note that the mentioned product suffix number denotes its pH value in this holistic leather-safe aniline leathers pH stabilizing system to eliminate water stains. Leather protein fiber is an amphoteric material while the other leather constituents like the tanning agents, dyestuffs and fatliquor are not. The iso-electric point (pI) of leather averages pH 4, water averages pH 7. Between pH 7 and pH 4 there is an ionic difference of 1000 (one thousand) times. Foreign pH influences below the pI charges the protein fiber ionic positive while above the pI causes the protein fiber to shift ionic negative. The ionic leather constituents and the protein fibers behave like magnets, unlike poles attracts.