Thank you for posting these very good pictures!
These “Vachetta” leather trim is also known as “Naked Leathers”.
They are “Vegetable Tanned” to give the extra firmness to retain the article shape.
These leathers are “fatliquor thirsty” and it is the fatliquor that helps to resist absorption and staining.
Fatliquor helps to retain its rich tone color too.
In most cases, when newly bought it is already in pale-biscuit color; a sign of diminishing fatliquor.
From production time until the item is bought; it may take years and all these while the fatliquor evaporates as VOC (Volatile Organic Compound).
"Vachetta" is the most sensitive among all leather types:
pH Sensitive – Its pH neutral is around 4 and any cleaning products above the pH of 7 will cause it to brown.
That’s the reason it comes to this brown color from perspiration stains that shift from the acidity to alkalinity.
Perspiration contains traces of urea that when aged and ferments with the natural bacteria from the air shift alkaline – that browns.
To reduce the browning a pH 2.0 acidifier may be applied to neutralize the alkalinity.
UV Sensitive – Unlike all other leathers that will fade and goes lighter in color these “vegetable tanned” leathers behave just like our skin – it goes darker (sun tanned).
This gives you a little idea about the chemistry reaction between the leather and the elements against it – that result in these conditions.
Here is my recommendation:
Phase 1 – Degreasing.
A low pH 2.2 Degreaser with Degreaser-2.2 is used to degrease the embedded body greasy perspiration stains.
This gel degreaser in soak, dwell and massage into the leather structure to Penetrate, Lubricate and Suspense these embedded stains.
Then it is followed with a thorough pH 3.0 rinsing with Rinse-3.0; hand squeezing or scudding and extract with terry towel until towel shows clean.
You would be amaze how much these thirsty leather have suck in all those foreign contamination – should have been the protective “fatliquor” instead.
Leave it to dry; as the foreign contamination wicks up; periodic extraction with terry towel helps remove these contaminations easier when it is completely dry.
When the leather is crispy dry foreign soiling particulates is further erase off the leather with Leather Eraser-4.
Phase 2 – Browning Treatment:
To reduce browning caused by Alkalinity through perspiration and or other alkaline cleaning solution Acidic solution is used.
First stage is to use a pH 2.0 acidifier with Acidifier-2.0 – spray, soak, agitate and leave to dry.
When dry use Leather Eraser-4 to erase further suspended foreign residue and inspect.
Repeat treatment as necessary, otherwise a leather-safe bleaching treatment is recommended.
A pH 3.5 d’Tannin-3.5 is necessary to do the bleaching effect follows by a pH 1.3 accelerator with d'Tarnish-1.3 to boost the working effect of d’Tannin-3.5.
Spray and let it soak evenly, extract with towel and leave it do dry naturally and inspect.
Foreign residue can be further erase with Leather Eraser-4 and inspect.
When the overall treatment is satisfactorily the leather is rinse with Rinse-3.0 as in phase 1 until the towel shows clean and may proceed with phase 3 while the leather is still damp (squeeze with dry towel).
Phase 3 – Leather Rejuvenating.
Since the leather has gone through phase 1 and 2 soaking through; Hydrator-3.3 treatment may be skipped but proceed with fatliquoring while the leather is evenly damp.
Fatliquor-5.0 is an anionic fatliquor that carries a (-) ionic charge.
It will penetrate and hydrogen-bond with the cationic leather fibrils which has a (+) ionic charge.
Fatliquor is an emulsion blend of natural “Fat, Oil and Water” used originally in the tannery.
As the water evaporates more fatliquor is applied as long as it penetrates.
Fatliquoring will enrich the tone of the leather, reduce absorbency, increase strength and suppleness and prevents leather cracking.
See this Discovery Channel video on “Fatliquoring”.
http://www.leathercleaningrestorationforum.com/forum/showthread.php?t=1772
Phase 4 – Abraded Skin Repair:
An option is to repair abraded skin due to dry and wet rubbing with Impregnator-26.
This skin repair with applying the transparent natural color Impregnator-26 is to impregnate worn leather grains and micro cracks.
It to fills and tightens with good leveling properties that is film forming for improve abrasion resistance.
Phase 5 – Rub Resistance Protector:
Use Leather Scent-D (draggy-feel with an unforgettable classical leather scent that charms).
To rectify this problem of greasy body stain on Vachetta leather; the above recommended procedure can only gives you a desirable result; whether you are a novice or a professional.
I have provided the “Science “in the products and also “Art” of how to accomplish it!
It is now up to you to follow through with understanding and patience.
Roger Koh
Leather Doctor®
Email me
[email protected] for the product price list.
The comprehensive product line can be found in this link: http://www.leathercleaningrestorationforum.com/forum/showthread.php?t=360