Vinegar and Iron

[Paddlefoot]

Some is Heinz and some is Albertson's or Von's store brand.

[LynnC]

I'm using cheap "Piggly Wiggly" brand white vinegar  - Works great!.........Lynn

[Mike Krall]

I've got a couple of questions...

Would pure, 99.7% acetic acid (16oz.) and iron filings (what amount???) be a good base for this stain or won't the same chemical reaction happen? Seems like a person could make a large amount of base stain this way.

The variation in color based on wood chemistry... If the stain used is "ferric", being red toned, what kinds of changes would a person see if the wood had a flood coat of concentrated tea applied (and dried) before hand?

Mike

[Long John]

Mike,

I doubt that 99% "pure" acetic acid is obtainable.  "Glacial acetic acid" is the most concentrated form generally available and it runs around 40%.

In order for any acid to work it must have sufficient water to permit the formation of hydronium ions H₃O+.  It is actually the hydronium ions that do the work.  Consequently, don't think that by using a more concentrated form of acid that you will get a more vivid color.  It doesn't work that way.  If the acid is too concentrated it will just char and weaken the wood when it is applied.

In a 1/2 gallon jug of commercial, off-the-shelf white cider vinegar I would use a length of unplated, rusted barbed wire about 1 foot long.  That should give you enough iron to get nice color.  I suppose you could use wine vinegar if you wanted.  I have never tried that.  I usually use the stain to whisker my stock so I generally apply 3 coats, de-whiskering well between coats.

Best Regards,

John Cholin

[Mike Krall]

John,

OK, I get it... and I appreciate the effort. Teaching well is an art. Starts with knowing a thing correctly and sometimes is like driving nails in oak... requires concentration on the task and follow though. Thank you.

If a concentrated black tea solution were applied to maple and dried prior to applying vinegar/iron stain, what would you expect to see? 

Mike

PS  http://secure.sciencecompany.com/Acetic-Acid-Glacial-16oz-P16220C0.aspx

[Mike Krall]

Well, I made up a batch of V/I with white vinegar and rusted barb wire. Put in more than one length of the wire and let it set 4 months. Filtered it through a paint filter and didn't get any residue to speak of. Let that set for a few days and took some off the top. It had a fair amount of black specks in it and looked muddy when applied to maple. Filtered the batch again, this time through a coffee filter. It is a lot clearer and is not as muddy looking.

I tested the stain this way:

1-4 applications on maple and maple washed with strong tea solution (6 bags per cup). The tea was left to dry before applying V/I stain. There were four concentrations of V/I... full strength, 3parts V/i & 1 part cider vinegar, 2 parts V/I & 2 parts cider vinegar, 1 part V/I & 3 parts cider vinegar. All applications were dried before additional applications.

I expected to see significant darkening with each application (1-4) but did not. I expected to see distinct differences between stain on bare wood and on tea stained wood but I didn't. I expected to see color change with various dilutions from full strength to 1 V/I & 3 vinegar and very barely did.

What is wrong with my expectations?

Mike

PS ~ I've got a batch of 1 V/I & 6 vinegar aging now but it will be days before I'll know if more dilution will get me red/brown or red/orange.