To me, a vinegar-based stain is the closest I’ve ever come to seeing real magic (and the neighborhood kids are as fascinated by it as I am). You put on a clear liquid, and, depending on the wood, from 10 to 20 minutes later, color appears. Color will depend on your formula components and the type of wood used.
Vinegar & Galvanized Nails is known as “Pickling,” and was popular in Colonial days for aging and graying-up wood. Simply, get a jar, pour in some distilled white vinegar, and wait a few days for the nails to dissolve. This does not produce a dark stain, but a light-to-deep gray on most woods. Stretch out your stain by diluting it with water up to 5-1 water/stain without loss of tint. Color can be tweaked with Universal Colorant or Acrylic craft paints.
Vinegar & Steel Wool or Iron Nails produces a darker stain, from a brown and reddish-brown on pine/fir trees, to a deep black on oak. Toss a hunk of steel wool or nails into a jar, cover with distilled white vinegar,cap the jar, and in about 24 hours your ‘stain’ will be ready. Leave the jar uncapped, and after about 24 hours, add some water to encourage oxidation (rust) for a more reddish hue. This type of stain can be diluted up to 20-1 with water, without loss of effect, or with tea or coffee to add a touch of reddish color. Colors can be tweaked with Universal Colorants or Acrylic craft paints.