Vinegar and Iron

[Long John]

Wood,

What alloy is the steel in the steel wool?  Common alloying elements are chromium, nickel and manganese.  Aoll of these produce green or blue oxides.  Consequently, I stay away form it for stock stain.  I just go out for a walk and brning back a foot or two of old barbed wire.  You can use cider vinegar or white vinegar.  Or, since its apple time you can take the last quarter of the jug of fresh cider you got this weekend and let it "turn".

1. Concetrated acetic acid is called "glacial acetic acid" and it is available from the chemical supply you local high school uses for cehistry supplies.  I have nver used it for stock staining.  Why when a 39 cent bottle of cider vinegar works well?
2. 2 weeks should be enough.  I have a masonry crock on the shelf that has been tere for about 15 years.  It has a Saran Wrap and rubber band lid.  When I notice that the liquid level has gone down I add a little randy apple cider or cider vinegar to it, depending upon the time of year.
 3. Rust is a mixture of iron oxides.  It doesn't matter.  Iron oxides are slightly soluble in acids.  But remember when you use the stain you want a clear liquid like tea.  You don't want a a muddy brown liquid.  If it looks muddy you have suspended iron oxide crystals in the stain which will tend to make the stock finish look muddy.  That's why I pour the stain solution of the top of a settled crock of iren and vinegar and dilute my stain with fresh vinegar.
4.  It doesn't smell any worse than salad dressing!  Acetic acid has a high vapor pressure at room temperature.  That means that it wants to evaporate.  If you leave it uncovered you will end up with a pile of rust in the bottl of a gar of water.  the acetic acid will leave by its own accord if you let it.  Keep your jar of stain covered.
5.  My stain crock is a 1/2 gallon masonry pot I bought at Colonial Williamsburg a bunch or years ago.  Before that it was a larg mayonaise jar with a rusted-out top.
6.  I don't think freezing will ruin the stain but it will stop the reaction that produces the iron acetates that do the staining.  It will also proable crack the crock or jar it is stored in.  Come spring you might have a mess.
7.  I don't know how dilute to make the hydrogen peroxide especially since hydrogen peroxide spontaneously decomposes at room temperature.  If you have a fresh bottle I suspect 25% or 50 % would be a reasonable start.  If the bottle is old it is probably already at 25%.

Best Regards,

John Cholin

[Darrin McDonal]

I just applied some vinegar stain / reagent that I mixed up and has been sitting for a good 6 mos. In interesting, very interesting. It turned out a beautiful vibrant silvery/gray on a scrap piece of curly maple. Not the color I would put on a gun stock but still a really cool color.
Anyone else get this color?
Darrin

[bob in the woods]

If gray, add more vineger.

[FG1]

Thats what I got Darrin . Kind of like laminate camoflaged stocks that Richards Microfit sells 

[Woodbutcher]

 Long John:
 You've put a lot into these posts. All of you have. Thank you!
 OK, I know of a couple of old barns and a couple of old buildings. I'll get some old nails and remove some rust. By weight you're only talking about a couple of ounces. The trick is to use iron, not steel.
 Barbed wire is available, but it's probably only 20 years old or so, and I have no way of knowing the alloy.
 Plastic for a lid and no bad smell, I'm in business.
 This is going to be fun!                        Woodbutcher

[pflyman]

Ok...I finished the pistol stock with 3 applications of Tom's 1/3 Mix- a paste of equal proportions of beeswax, boiled linseed oil, and turpentine.  I found it easy to apply and dries quickly to a soft, velvety finish.  No tacky feel as I anticipated.  We will see how it holds up, but it certainly goes on easily and provides an attractive finish.  When initially applied, the stain went on light brown but turned a decided grey.  After the beeswax, you be the judge: grey, green, brown, or a bit of all three?  The light makes a decided difference.  I am currently mixing a new batch of stain.   Apple cider vinegar with rusty barb wire, no heat and more time.  It appears to be brewing well.   I hope the photo comes through.

[Long John]

Even though the stock wood is beech, the color you have sugggests that you had a very iron-rich solution.  When you saw the stock turn gray that was your indication that you were getting ferrous oxide forming as the acetate left the stock.  You could have applied straight vinegar to redden the color or used hydrogen peroxide.  Either would have caused a shift towards ferric oxide and given you a redder color.

When you use a vinegar/iron stain you are in control of the color.  Yuo can get anything from black to red by manipulating the chemistry a little.  With a nitric acid/iron stain you have much less control; you get just reddish brown.

Best Regards,

John Cholin

[Seven]

I'd also like to point something out that has been hinted around a little bit.  I had a batch of the vinegar stain brewing from a while ago.  It looked pretty gross when put on wood, dark and blotchy and not at all like I'd seen others accomplish.  At first I thought it was in the state that Long John describes as iron saturated, so I put in more steel wool.  Same results, yuck!!  Then on a whim I threw in an old rusty nail.  About two weeks later the stain is a whole different brew.  I'm attributing my first result of this batch on using steel wool.  And once I finally got some real iron in there it turned the stain right around into something usable.  You guys can experiment some more if you want, but I'm sold on iron and not steel wool for future projects.  -Chad

[pflyman]

I have to agree with you, Chad.  My first batch which I used to stain the pistol, contained steel wool- the first batch heated and then eventually I added washed (degreased) steel wool.  The degreased steel wool still looks shiny and does not appear to have oxidized.  Perhaps the acid in the vinegar has attenuated.   The batch I have brewing now used rusty barbed wire and it continues to react.   Although I haven't tried it yet, this will be my formula for future trials and the steel wool is out.

Dave

[rich pierce]

I'm not 100% sure the type of steel or iron is the main variable.  I know John uses old rusty barbed wire successfully.  As far as I know (I built and repaired a lot of barbed wire fence in my youth) all barbed wire since WWII has been galvanized- coated with zinc.  It may be rusted up now but unless you find old forms of barbed wire- like the type that is twisted spiky ribbon, not wire with barbs attached- it likely has lots of zinc still in there somewhere.  Any barbed wire from before WWII is probably underground or dissolved unless it's found in a barn.

It is just as likely that something else (not zinc) in steel wool can cause a problem.  Old mild square nails (not modern hardened masonry nails) would be my best bet for unalloyed iron.  But of course ore from different areas has different composition, etc.  So maybe it's not the source of iron used that is the primary variable.

[Dphariss]

Even though the stock wood is beech, the color you have sugggests that you had a very iron-rich solution.  When you saw the stock turn gray that was your indication that you were getting ferrous oxide forming as the acetate left the stock.  You could have applied straight vinegar to redden the color or used hydrogen peroxide.  Either would have caused a shift towards ferric oxide and given you a redder color.

When you use a vinegar/iron stain you are in control of the color.  Yuo can get anything from black to red by manipulating the chemistry a little.  With a nitric acid/iron stain you have much less control; you get just reddish brown.

Best Regards,

John Cholin

It is impossible to get "iron rich" vinegar stain with over the counter vinegar. At least as compared to AF/Nitrate of Iron. Its too weak to dissolve much iron. As a result it does not stain the wood in the same matter as AF will.
This is probably why nitrate of iron was used historically.
Vinegar/iron was used as a *tint* for cabinets and furniture. Its was not used as a stain historically or so I am told by good authority.
I would also point to the fact that hydrogen peroxide was pretty rare in the 18th century since it *did not exist* being a man made chemical first produced in 1818.

I am also told that the color of the iron oxide is determined by the water molecules attached to it. Black or grey has more water, redder has less to none.

I would also point out that the red is actually correct for Nitrate of Iron stained maple though some *may* be more honey colored.
I have no desire for a grey/brown or green/brown or other weird colored gunstock.

Unless you dye the wood it is very difficult to get "the color you want" in maple. I use AF/nitrate of iron stain and I know its right for a maple stocked longrifle. Some maple stocks were not stained at all and simply varnished with a dark, reddish oil based varnish perhaps made with leaded boiled oil and sandarac. This varnish looks like this. Sorta reddish even though put on circa 1850-60. This is a traditional finish, used on maple with no stain at all so far as I can tell.



This is a "Connestoga Rifle Works" (Leman) 54 caliber FS in unused condition. It is coated with a red varnish. It is dated on the lock 1840.


Nitrate of iron may look like this:


Or this:


Or this:


Depending on the wood and the batch of stain the range of colors above is typical.

The new rifles only have 2 coats of finish in these photos.
You will note in the photos of the 2 original rifles that the common undertone is red.

The red falls into the realm of AF stains or red/reddish varnishes made with an oil with reddish tones as a result of its formulation o the varnish was intentionally colored a translucent red as in the case of the Leman. Thus while there are rifles with stocks of other colors we can assume that the red/gold or red/brown stain produced with AF and/or shop made or purchased oil based vanishes are correct from the historical perspective for a wide range of rifles.

There ARE exceptions, but note the color of the wood UNDER the varnish on the late Hawken rifle. Its honey colored where the varnish has worn away (note its not chipped or flaked). So when you see a light honey colored rifle with traces of a reddish brown varnish in protected areas you can assume the rifle was probably varnished with a shop made varnish originally and that it was reddish brown when new.
Now if you dislike AF color or that produced by the vanishes such as those above by all means stain as you like.

But do not scoff at red/gold or reddish/brown. It is irrefutably historically correct for American rifles for at least 130+ year span from circa the F&I war to the end of serious ML production in the 1880s-90s.

Dan

[Trkdriver99]

I really like the looks of the pistol. I like the way the curl shows up and just the looks in general. I have a box of old square nails ( I believe some are hand forged ) that I got in a junk store in Maine. I think they will work well in my wife's vinegar..

Ronnie

[Ohioan]

Alright, so this thread got me interested, and a bough some apple cider vinegar.

Into a clean half gallon milk jug I poured 4 cups of vinegar and about 3 oz of 0000 steel wool. 

Is that enough vinegar:steel or should I pour in more vinegar? 

I'm mostly worried about keeping the reaction going.

thanks

[Paddlefoot]

This brew makes a great black leather dye too.

[Long John]

Zach,

Vinegar/iron stain is easier than you are making it.  No measuring is required.  I do NOT recommend using steel wool as you have no idea of how much alloying is present in the steel wool.  The only reason to use steel wool is that the fine texture of the steel wool allows for a faster reaction. 

I would get a 1 quart mayonaise jar with a plastic lid and fill it with vinegar.  Toss in a small hand full of nails, the older the better for the same reason that steel wool is not ideal, or old rusty barbed wire. (Rich I appreciate your observations but the barbed wire I have access to shows no evidence of zinc plating.)  Or you can saw pieces of an old horseshoe.  Just get the purest iron you can, toss in a hand full, put the lid on the jar and put it up on the shelf for a couple of weeks.  That's all there is to it!

When you try your stain out it might turn the wood gray.  If it does that means you got ferrous acetate rather than ferric acetate in the solution.  Pour some of your stain solution into a clean plastic cup and add fresh vinegar.  Stir gently for a few minutes.  Now when you use the stain you should end up with a brownish orange color.  That's how I got the color below.



You might notice that it looks a lot like the color obtained by Dan with nitric acid/iron stain.  That's because the reddish brown color comes from ferric oxide and ferrosoferric oxide.  In the case of the vinegar iron stain the acetic acid in the vinegar ionizes the iron, dissolving it.  When the stain is applied the acetic acid evaporates, leaving the iron ions behind which snag onto oxygen atoms from the air and form iron oxides.  When nitric acid is used the acid ionizes the iron, dissolving it.  When the stain is applied the nitric acid will very slowly evaporate away over the course of many weeks or you can speed it up by heating the stock.  This drives the nitric acid off as a vapor, leaving the iron ions behind.  The iron ions snag oxygen from the air forming iron oxides.  The iron oxides don't know how the iron ions were formed.  They don't care.

There are advantages to each staining system.  I like the vinegar iron system.  Others prefer the nitric acid system.  When you add hydrochloric acid to the mix you complicate the chemistry because the hydrochloric acid has a much lower vapor pressure and must be heated longer and hotter to drive it off the stock.

Some others have made certain statements about the chemistry that I believe are incorrect, but this is a free country and they have the right to believe what they wish.   Furthermore, I have no need to change their minds.

Best Regards,

John Cholin

[Paddlefoot]

Hey John, I hit upon a source for cast iron. Brake drums or rotors. they get changed frequently enough you could probably get one for free at a local repair shop. Old Harley cylinders are also iron and the fins break off pretty easy if you want to put a small batch together. Not sure if these sources are pure iron, maybe someone else knows but brake rotors flash rust right now when you wash your car so I gotta figure they are relativly pure.
I haven't played around with the batch I made from letting the vinegar stand in the old rusty dutch oven so it will be interesting to see how that works. It's been sitting a good 18 months.

[Acer Saccharum]

John, you are hard to beat when it comes to vinegar and iron!

This is why you were elected as grand poobah of the Betheren of the Vinegar Stain. You rock.

The iron oxides don't know how the iron ions were formed.  They don't care.
Something I did not know about Aqua Fortis: the color will change over time, heating just causes the change to come sooner. Do I have that right?

Thanks

by the way, Grrrreat color on a sweet rifle!

[old guy]

Shortly after this thread started I replaced a porch floor and I started a batch
using the old cut nails. Well she looks good and stout now (about like the coffee
they used to brew on the mountain farm).
My question is    do I leave the nails in or remove them after a period of time
and can the be used a second time.  Just courious.

Leo( old guy)
By the way, i;ll be 70 this winter and I was youngest one on crew for the church
porch floors.

[Long John]

Friends,

To answer a few of the questions, I have the following:

Paddlefoot,  When I reconstrcuted the explosion at Jahn Foundry several years ago I learned that they were making bread drums and rotors for Chevrolet and Saturn vehicles at the time of the explosion.  These components were "gray iron" with a veryhigh purity.  I suspect that analogous parts of other cars are also gray iron.  If I had a Harley I would ride it!  If the cooling fins break off easily it is probably quite pure iron.

Acer,  In theory the nitric acid will slowly evaporate by itself given enough time.  As it does the iron ions will combine with atmospheric oxygen and produce the oxides we seek.  However, strong acids will also attack the cellulose in the wood, producing a chemical char.  That's right, a char, just like you get when you expose wood to temperatures above 425 F.  This is why some stocks stained with strong acids like nitric or hydrochloric continue to get darker and darker until they are essentuially black.  Residual acid in the wood chars the wood over time.  The key to avoiding this is to use a diluted solution.  Most of the recipes for nitric acid/iron stain call for some pretty healthy dilution for good reason.  When you dilute the solution you are also diluting the concentration of iron ions.  One advantage of vinegar is that it is not strong enough to cause a chemical char of the wood.  A dissadvantage of vinegar is that it is marginally strong enough to produce a preponerance of ferric ions over the ferrous ions.  When you dilute the nitric acid enough to avoid charring you essentially have an acid of similar strength to the acetic acid in vinegar.  So there is some convergence here, the two methods end up yielding very similar results most of the time.

Leo,  I have an old earthen-ware crock that i tossed some nails and old rusty barbed wire in about 20 years ago.  I never took anything but clear stain out of the crock by gently pouring it off the top of the mix.  If I stir the mix the thing is a muddy brown.  If I leave it sit the liquid looks like tea.  I don't know if your should remove the nails or not.  I didn't.  But, when I started using my stain for the rifle I pictured above it was too blackish-brown for what I wanted so I added fresh vinegar to some decanted stain mixed it and that reddened the color nicely.  I suppose you could achieve the same result by removing the source of iron once the stain was giving the color you wanted but you will have to put a vapor-tight lid on the jar to keep the acetic acid from evaporating out of the solution.  If it does youwill get rust (iron oxide) precipitating out of solution as a layer on the bottom of your jar.

There is also the assertion that vinegar/iron stain is not historically documented.  I am NOT a historian.  I do not while away the hours reading historical documents.  So I don't know if there is any documentation to support the use of vinegar/iron stain.  But I do know that every old homestead had apple trees as pickeling was a well-used method of preserving foods. Pickeling is essentially boiling in vinegar.  So the early 18th century gunmakers had access to vinegar.  It was ubiquitous in the settlements.  I read somewhere that vinegar and iron stain was used to stain leather (it stains leather a deep black) since the middle ages.  It is not too large a stretch to conclude that some one might have tried to stain maple with the stain they used for harnesses.  Indeed, I remember a post on this board that refered to an add in the Philadelphia Gazette for a lost rifle that was "stained dark with aqua fortis".  This language suggests that staining dark with aqua fortis was out-of-the-ordinary for the time.  Otherwise, why include it as a distinguishing attribute for the rifle?  The language in the add seems to imply that some other stain was more commonly used and resulted in a color that was not so dark.

Can I prove that vinegar and iron were used by colonial gunmakers?  No.  It was cheap and readily available in colonial America.  It would do the job. Furthermore, I have a little difficulty believing that some one could successfully transport a glass ampule of nitric acid down the wagon road from Philadelphia to Lancaster, Reading or North Hampton in the back of a freight wagon in the decades preceding the American Revolution.  But I use it because I like the results I get with it.

Best Regards,

John Cholin

[Mad Monk]

John,

I suspect that both the vinegar and iron stain and the nitrate of iron stain were period correct.

"Furthermore, I have a little difficulty believing that some one could successfully transport a glass ampule of nitric acid down the wagon raod from Philadelphia to Lancaster, Reading or North Hampton in the back of a frieght wagon in the decades preceding the American Revolution."

James Whisker's writings show the sale of nitric acid to a gunsmith in the 1820's in Bedford County, PA.

Nitric acid was used extensively in fabric dyes.  Look at Rev War officer's uniforms.  The "buff" facing was dyed with nitrate of iron.  This could be used on wool, lionen or cotton fabrics.  When dyed with nitrate of iron and then dipped into a strong solution of tannic acid you got a dark brown.  When dipped in a solution of gallic acid you got a jet-black color.
Production of mineral acids in Philadelphia was one of the early industries.  The two document acid works could not begin to keep up with the demand so large amounts of the mineral acids had to be imported from England.

The question of availability away from Philadelphia probably centers on the completion of the Schuylkill River Canal and the Union Canal out of Reading.

I do know that prior to the building of the Schuylkill River Canal the iron products produced in Berks County went down to Philadelphia by horse drawn wagons.  Hauling back supplies needed in the area.


The question begs.  Why wouldn't vinegar have been used.  Sour wine vinegar was used to manufacture cupric acetate and lead acetate way back in time.  In 50 A.D. Pliny, the Elder, wrote on how to test the purity of cupric acetate to see if it had been adulterated with cheaper iron salts, ie., ferrous sulfate.  Using a strip of reed soaked in gallic acid.  He would take some of the sample to be tested.  Dissolve it in water and then dip the gallic acid treated reed into the solution.  If the reed turned black he knew it had iron salts added.

Lead or copper plates would be suspended in a crock.  Sour wine vinegar would be poured into the crock.  Not enough to touch the plates.  The fumes from the vinegar being far more reactive (corrosive) than if you immersed the metal into the vinegar.  Far faster to use the fumes that to submerge into the liquid.
This goes back to the ancient Greeks as Pliny, the Elder, simply rewrote a lot of older Greek information.

Cider vinegar runs about 4% acetic acid while sour wine vinegar runs around 8% acetic acid.

The acetate "acid metal salts" were also widely used in fabric dye work.

In terms of length of history and amounts used the vinegar metal salts were better known and more widely used.

You see in old writings the mention of "green hides" going into a tannery.  When I worked on the copper acetate horn dye I had been dealing with the Museum Of The Fur Trade.  When I told them what I had found and what I was doing they told me that I had solved a mystery that had puzzled them.  They found very large amounts of cupric acetate had gone west in the trade system.  Being very toxic it could not have been used to worm livestock.  It was actually used to treat hides being shipped back east to the tanneries.
Cupric acetate was also used to treat cattle horns prior to shipment over long distances.
In both cases the cupric acetate acted as an bacterial killing agent and protected the goods from insect attack.

To sum all of this up.  Here we have something in wide use all over the world at the time in question.  Why would it not be used to color wood.  Very large amounts then being used to color various fabrics.

The thing about the use of nitric acid is that you can get a lot more iron into the liquid compared to vinegar.

As long as you are using iron oxide as the colorant you will get darkening of the stock in varying degrees.  Depends on how much iron oxide you get in and on the wood and how much tannic acid is in the wood.  The tannic acid reacts with the iron oxide to give an iron tannate complex that is jet-black in color in the curl and a general overall darkening.  I would point out that prior to the introduction of steel pen points during the Civil War the standard writing ink was a mixture of ferrous sulfate and tannic acid that you mixed with water.

Bill K.

[Ohioan]

John,
   
      The reason I measured is because I would like to be able to easily reproduce the same outcome if I like the stain.  It's my attempt to be scientific.

The gun you posted has a beautiful color to it. 

I stained my first and only gun with Aqua Fortis that I made.  It worked well, and I'm pleased with the color.   The only issue I have is that Nitric Acid is hard to find and is relatively expensive.

I think I might mix up another batch of vinegar/iron stain.  This time use a scrap brake rotor.  There would only be a weeks worth of time difference between my first batch and this batch.  Then compare.

[Acer Saccharum]

Zach, you have mentioned the very fly in the ointment......  quest for repeatable results.

Ah, Grasshopper! You wish consistency in a sea of change!

The only thing consistent I have gotten out of vinegar stain is that I usually like the color I get.

The most frustrating thing I have found is to have a certain color in mind, and then try to reproduce it in the flesh.

The color you get is a reaction between the stain and the wood. The color you get will be a collaboration between the chemicals/minerals in the wood, and the acid/iron ratio in the stain itself.

[Paddlefoot]

Just another Idea for iron sources. Quite a bit of old machinery was made of cast grey iron. For a few years I was a printer working on some fairly outdated equipment. A lot of pieces had to be handled with some caution because they were iron and would break if you dropped them or hit them just right. I'm sure there must be old abandoned pieces of equipment laying around at swap meets and junk yards that could give up a hunk of iron for a batch of stain.

[Ionian]

I am using stove pipe wire and it's working real well. I have noticed that when I put the wire in the vinegar it was heavily rusted and in a couple of days it removed all the rust off and the wire now looks clean. I assume the acid will keep working on the rest of it. My question is that when you use the stain, do you have to strain it first? I have a lot of rust in the bottom of the jar and I could see through the vinegar unless I stir it.

[T*O*F]

Go to your local brake shop.  Ask them for a jarful of the turnings from their drum and rotor turning lathe.  These turnings are iron. They are in a form that will give maximum reaction time whereas with nails or wire you have to wait.  Saves waiting weeks.

They will contain a fair amount of dirt.  Sock them first in a cotton sock or a a piece of flannel.  Then pick up the remainder with a magnet to further remove any clunkers.