Chromium Trioxide

[Beekeeper]

I know I can get it from Dixie Gun Works but the shipping is more than the cost of the product.
It is used for stock stain. Turns a light wood a purple color. Looks great on an old rebuild or restore.
Would like to find somewhere local that I can get it instead of paying the blood money.


Jim

[deltaenterprizes]

Try local chemical supply house.

[405]

I'm down to my last 1oz of it. Didn't know it was still available from Dixie. Good to know just in case. I think most places quit carrying/shipping it in liquid form maybe because of Hazmat concerns? It does work. Results depend on elements and chems in the wood. Can leave some woods with anything from a greenish tint to a red tint. Does bring out grain (figure) well.

One alternative to chromium trioxide is aqua fortis (weak solution of nitric acid-water). In some ways it acts similar to CrO3. It is available thru Track of the Wolf and likely some other suppliers. I've found it to work well also. If used in conjuntion with the Laurel Mtn. alcohol/water based stains the results can be tuned to exactly the right color hue for any taste.

[bohica2xo]

Thanks to some industrial users who had lousy habbits, Chromium VI is now the boogeyman.

Chromic acid used to be the standard cleaning agent for laboratory glassware. Brass processors had tanks of it as well. I recall seeing entire musical instruments dipped into chromic acid tanks for cleaning - an entire school band worth of them at a time.

A weak chromic acid solution for staining could be prepared from anhydrous chromic acid (dry material) easily enough if you happen across any.

B.

[Beekeeper]

The dry kind is what they are selling at Dixie Gun Works.
Is there anything that will do the same thing that is comercially available?
Wallyworld maybe.

405 ,
What color does the chromac trioxide turn the wood?
Maybe I can concoct an alcohol stain that will do the same thing..
There are no chemical supply houses within 100 miles of where I live so it is make something or do without as Dixie Gun Works sells the powder for $6.00 but charges $7.95 to mail it and there may even be a hazmat fee.I didn't get that far in the order process.


Jim

[1874Sharps]

Gentlemen,

If you use hexavalent chrome (such as CrO3) be exceedingly careful as it is highly toxic!!! Chromium trioxide is also a powerful oxidizer and can cause alcohol to combust if it comes in contact with it, so caution on the alcohol based dyes. An alternative to a chromate solution for a finish is the Hershal House method I saw on his video. He used an iron-hydrochloric acid-nitric acid solution, as I recall (he put it on by hand without gloves, too --- yikes!). I am not an expert on finishing guns, but I know a little about chemistry and would hate to hear of any mishaps happening to any of you!

[405]

I used to hang out in a custom gun shop a lot. Watched the masters use the CrO3. So when I got into stock finishes and refinishing for my own guns I followed their lead. The small amount I have left is the liquid form so have no idea about the powdered granules from Dixie? For pulling out figure in tiger maple or other figured, dense wood the CrO3 was hard to beat. The aqua fortis (weak nitric acid sol) seems to do almost as good a job and is in many ways similar.

It's hard to say exactly what color or hue will result in the use of either chemical. It all depends on the actual trace elements and other chemicals that are in the wood... or so I'm told by the folks who finish hundreds of stocks (mostly maple). I have not had it happen but have seen the CrO3 leave a slightly greenish hue to some maple. Sometimes I've had it leave a deep brown with reddish hue... thus requiring no additional stain. The most common result I've had with maple is that it leaves a golden hue leaning toward very faint reddish hue.

The aqua fortis is similar but have had less experience with it. It brings out figure well especially if gently heated just after applying. It also tends toward a golden hue on maple.

All that is based on starting with clean, freshly sanded wood. If the stock is a refinish where the old finish is chemically stripped off or if it is sanded off the results can vary widely. What happens I'm sure is that there may be a chemical reaction between the CrO3 or aqua fortis and the residual oils or other chems still in the wood from previous finishes or even the finish remover. The best results I've had have been with "new" fresh, clean wood.

When applying either chemical it seems best to use something like OOOO steel wool as the applicator. The iron in the steel wool may actually add a little of the red color (iron oxide) to the final color. Apply liberally. Let dry. Sand lightly or brush with OOOO steel wool. Wipe surface with clean cloth. Repeat above until desired effect. Let dry completely. Clean then add water/alcohol based stain for desired color and hue. Let dry. Remove whiskers if any by lightly brushing with OOOO steel wool or 400-600 grit paper. Clean with cloth. Apply final oil or varnish type finish.

For most any stock the simplest and cheapest commercial stain may be the regular and widely available water/alcohol based Birchwood Casey Walnut stain. The home brew possibilities are nearly endless. Mixtures of food colorings come to mind. I've used brown Kiwi shoe polish mixed with denatured alcohol. Have also had good results with regular Flebing's brown leather dye. And on and on. Seems most any reasonable stain will also bring out some figure. The chems like CrO3 and aqua fortis are just the "specialists" in doing the job. And the best thing about the "known" chems like CrO3, aqua fortis and the stains like the Laurel Mtn series is that they are all tried and proven and have more controlled and predictable results. In any case, it's always a good idea to test any chem prep or stain on a piece of non-critical wood of the stock like the area in the barrel channel or under the butt plate, etc.

Walnut stock treatment is a horse of a different color. :mrgreen:

[bohica2xo]

Just so we are clear here, we are talking about a WEAK solution of chromic acid.

Yes, pure chromium trioxide is a powerful oxidizer and should be handled carefully. It will indeed initiate combustion if mixed with ethanol.

For a frame of reference, a 5% solution (by weight) of chromic acid & DI water cleans aluminum quite well. Solutions for staining wood may not need much concentration to be effective - start at 2% and see what the results are.

Chromium VI gives up oxygen easily. As it gives up this oxygen, it eventually becomes the reduced blue/green color. The reason you see green in some woods is most likely a reducing reaction with something in the wood.

The DGW price for chromic acid looks like a bargain compared to reagent grade material. A 500ml bottle of 20% concentration in H2O will cost you about 60 bucks.

If you want a solvent to add to the already diluted solution, you can add acetone. Chromium VI mixed with aqueous sulphuric acid and acetone is known as "Jones Reagent". Since Jones Reagent does not generally affect saturated bonds, it might have an interesting effect on raw wood...

B.

[Old Ironsights]

I know I can get it from Dixie Gun Works but the shipping is more than the cost of the product.
It is used for stock stain. Turns a light wood a purple color. Looks great on an old rebuild or restore.
Would like to find somewhere local that I can get it instead of paying the blood money.


Jim
I like 4-aminal, biphenal, hexachlorobenzine &/or strontium chromate... :twisted:

[1874Sharps]

Bohica2x0,

You are a chemist! If I had to guess I would say you are an organic chemist and you are most aliphatically correct!

[405]

Beekeeper,
Here's a pic of a tiger maple stock. The stock wood was "new" clean and fresh wood. The Cr03 was applied. Let dry. Then a dilute solution of Laurel Mtn Lancaster Maple stain applied. Final finish was Tru Oil/linseed/thinner mixed. About three light coats- rubbed in- dried between coats. The reddish-brown tint is mostly from the stain. The figure is enhanced by the CrO3. I've had similar results with dilute nitric acid solution (aqua fortis).

[1874Sharps]

405,

That is a nice stock and great work!

[405]

Thnx,
I think mother nature deserves most of the credit tho