I've been using this stuff for a few years. I've been puzzled by why sometimes it took days to dissolve the steel wool and othertimes it happened overnight.
I think I stumbled on it.
Some of the steel wool needs to be exposed to the air!
If the wool is completely submerged it takes forever to dissolve. If the wool extends above the liquid surface then it dissolves pronto. I think I discovered this as I was monitoring a batch for several days and observed the vinegar slowly evaporating until the wool broke the surface. Next day all the wool was gone.
I haven't had the need to use this anymore. So if any of you fellers care to test my hypothesis I'd appreciate the feedback.
Time for some basics here.
Cider vinegar is 4% acetic acid.
Wine vinegar is 8% acetic acid.
The vinegar does not dissolve the iron. Acetic acid is corrosive to most metals. For a few thousand years it was used to make copper acetate and lead acetate.
The fumes given off by vinegar are more corrosive than the liquid itself. In producing copper acetate and lead acetate the plates of pure metal were suspended above the liquid in covered crocks. The copper acetate or lead acetate then formed on the surfaces of the plates.
This holds true for how it reacts with iron.
For use as a wood stain or dye for cloth or leather.
The metal plates would be dipped into the pool of vinegar in the bottom of the crock. Any acetate form of the metal would dissolve in the pool of vinegar. Then the plates would go through another vapor exposure. Then dipped in the pool again. This would be repeated until the available acetic acid had been used up or the proper dye/stain concentration had been reached in the pool in the bottom of the crock.
The acetate form of lead, copper or iron is unstable in contact with air. You must keep some excess acetic acid in the dye or stain solution. By "unstable" I don't mean it will blow up. The acetate form of these metals is not the environmentaly stable form. Acetate of iron (ferric acetate) will quickly convert to iron oxide in contact with air. Lead and copper acetate will quickly convert to the carbonate using carbon dioxide from the air.
Bill K.