Sticky/Tacky dyes on body oils

Hello,
I frequently encounter body oil staining on aniline and full finish leather upholstery. The leather may be damaged but the dyes are not tacky. I have actually replaced the area with a new piece of leather and colored to match with my dyes and topcoat. The new leather often becomes tacky because the owner still has a body oil issue and the dyes become tacky. Also, the new dyes and top coats often make the leather more stiff, less supple, than the original dyes. Either the dyes, the topcoat, or both are not the same as those originally applied to the leather because the original dyes do not become tacky. I have a few questions and appreciate suggestions.
1. Who provides dyes and topcoats that perform as the original products on leather especially when encountering body oils?
2. What is the difference between those products and the ones that become tacky?
3. How are they applied?
4. Can they be applied evenly by hand instead of spraying?
5. Last, how is an oil pull up leather made? Are the dyes different than aniline dyes? What is the oil product that is used and how it it applied?

Thank you for your help.
Sincerely,
Frank

>>> 1. Who provides dyes and topcoats that perform as the original products on leather especially when encountering body oils?
http://leatherdoctor.com/ besides there are plenty of other suppliers.


>>> 2. What is the difference between those products and the ones that become tacky?
Crosslinker-25 http://www.leatherdoctor.com/crosslinker-25/ is used to control sticky issue to tie up the water element that cause the stickiness.


>>> 3. How are they applied?
Most application is applied with airbrushing at 80 to 100psi


>>> 4. Can they be applied evenly by hand instead of spraying?
Fashion done by hand originally is known as “wipe effect” and there are numerous finishes types that is done by hand. An even appearance is best done with airbrushing.


>>> 5. Last, how is an oil pull up leather made?
Oil pull up leathers are first aniline dyed, fatliquored with Fatliquor-5.0 as the primary conditioner and a secondary conditioner such as EffectOil-2.8 http://www.leatherdoctor.com/effectoil-2-8/ as the secondary fashion effect.


>>> Are the dyes different than aniline dyes?
Dyestuff used originally is the staining type such as Aniline-21 http://www.leatherdoctor.com/aniline-21/ used before the EffectOil-2.8 in this sequence Aniline-21 > Fatliquor-5.0 > EffectOil-2.8.


>>> What is the oil product that is used and how it it applied?
EffectOil-2.8 in the above sequence, it has to be soak up by the leather structure both for the primary (fatliquor-5.0) and secondary application (EffectOil-2.8).

Roger Koh
Leather Care System Formulator
Consultant / Practitioner / Instructor
web: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]

Hey Roger,
Thank you for the replies. Couple of questions:
1. I use a crosslinker in my topcoat. If oils are present body heat will bring it to the surface and the dyes that I am using will become tacky.
2. When applying your fat liquor and EffectOil 2.8 will the dyes separate when you run your finger against the underside of the leather?

Frank

>>> 1. I use a crosslinker in my topcoat.

What crosslinker are you using?
What was the percentage use?
What topcoat are you using?


>>> If oils are present body heat will bring it to the surface

If body oil, grease and sweat are present they should be degreased until the wet surface feels squeaky, that the pH chemistry integrity is achieved prior to any dyestuff or topcoat used.


>>> and the dyes that I am using will become tacky.

What dye types are you talking about “staining” or “coating” aniline dyestuff or are you talking about pigments become tacky? Another tackiness is related to the leather structure often a pH problem where the leather structure is not at its pH neutral (iso-electric point or pI). pH balanced with products lower then 3 will rectify potential tackiness. Structural tackiness is the breaking of hydrogen bond between the tanning agent and the amphoteric leather protein fiber and the leather denatures. When the leather structure becomes tacky surface coating fails as well and becomes tacky too.


>>> 2. When applying your fat liquor and EffectOil 2.8 will the dyes separate when you run your finger against the underside of the leather?

As mentioned above about the pH integrity of the leather, when the leather denatures and becomes tacky all other constituents will fail like a domino effect that includes the, dyestuff, pigment, Fatliquor-5.0 and the EffectOil-2.8 as well.


Roger Koh
Leather Care System Formulator
Consultant / Practitioner / Instructor
web: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]