>>> What does surfactant 3.6 do?
LeatherSurfactant-3.6 by Leather Doctor is a pH 3.6 leather-safe water-based surface-active-agent solution for lowering the surface tension so as to improve structure penetration to give better adhesion properties. It also facilitates the penetration and distribution of impregnation resin and adhesion coating. And also improves the uniformity for dyestuff staining thus reducing blotchiness.
Instruction:
1 Spray over the surface, brush-in accordingly to break surface tension for an even appearance.
2 Towel extract until it shows dry and is ready to proceed with the desired application.
https://www.leatherdoctor.com/leathersurfactant-3-6/
>>> ItÂ’s not in the kit.
You can purchase as an add-on to any of the kit . . .
https://www.leatherdoctor.com/leathersurfactant-3-6/
>>> Does the topcoat not adhere well because the leather is dry?
There are many reasons, grease is one, the other is that the surface is dry rotting, and many other reasons, that is why Adhesor-73, Aniline-76 is used prior to AnilineTop-76G.
>>> Also, can sand2000 smoothen out the leather when itÂ’s patchy?
You are taking a big risk of “suede” the leather if it's “grain”.
Patchy of remaining unwanted finishes may need the help of a stripping brush
https://www.leatherdoctor.com/strippingbrush-9/
>>> This area is already smooth, and I donÂ’t want to risk breaking the stitches.
Never use Sand2000 on crust leather and stitches, only to smooth out topcoats.