Order of finish

[Zonker1972]

you can and should treat the leather with a sodium bicarb solution to neutralize the acid in the 'groon. for a sodium bicarb solution, dissolve some baking soda, not baking powder, in water. i heated mine up on the stove. let it cool and store in a bottle just like the 'groon. dip the leather in the sodium bicarb solution for about 5 minutes. this sodium bicarb treatment will neutralize the  acid, vinegar is a weak acetic acid, and get rid of some of the vinegar smell.

this treatment may address the corroding/tarnishing of some metals that maxdaddy spoke noted

[maxdaddy]

23 hours ago, 1961Mike said:

OK, mine has NEVER looked that bad and I"m on my second batch

  That jar has remnants of every nail, steel wool, washers, and other flotsam that has ever been put in it going back about five years. Maybe once a year I'll scoop off the solids from the surface but I never empty it out and start from a fresh clean jar. When the liquid gets low I just stir in more vinegar and nails. It has never failed to produce nice deep black results. 

[MarlinDave]

I made a reinforcement panel for an Avenger type holster. Dyed it with vinegroon before stitching. Apparently hardened the leather. My machine won’t sew it, but sews un dyed scraps of the same hide fine.