Nitric Acid Stain

[Mtgelaude]

I am in the process of making my own stain for curly maple using nitric acid and distilled water in a 5/1 solution. Going to split it up and try adding iron from different sources and see how it work out. My intention is to have one batch with wrought Iron added, another with some 1095 steel I have, and the last batch be a basic acid/water mix. I like the colors I’ve seen from solutions with no iron, which is why I’m trying this in the first place, otherwise I would have bought the iron nitrate stain from Kibler and saved myself the trouble….and possible melting flesh. Jim Kiblers videos of staining stocks he’s just using examination gloves, so it can’t be that aggressive.

So, the question I have is how safe will it be to apply this as is, do I NEED gloves to keep my skin intact. Adding iron will take Some of the fight out of it, but the basic batch of nitric acid/water is my concern. I started off with a 4/1 ratio, but decided to add another part of water just to be safe.

Thanks in advance for any help.

PS, I’ve searched the heck out of this subject, in different forums, YouTube, etc.

 

[dave_person]

Hi,
I assume your maple turns yellowish pink after blushing with heat when you use just the nitric acid. The iron rust (ferric oxide) is what gives the reddish brown tones to the traditional stain. The potency of the acid in stains made from ferric nitrate powder and water is very low compared with the stain created with actual nitric acid. I still wear nitrile gloves when using it. The nitric acid I have is a 10% solution, which is not terribly aggressive but still requires rubber gloves and I like those that reach up the arm. Theoretically, you do not have to neutralize the ferric nitrate stain after blushing like you do if using nitric acid. I still either wipe the stock with ammonia or coat with lye water just to make sure any residual hydrogen ions are neutralized even though that may be unnecessary. Good luck with your experiments and please post photos of your results.

dave

 

[James Kibler]

It's probably best to use gloves, but I didn't for many years. It will stain your hands a bit, but other than that, I've not had any problems.

As far as neutralizing, this is personal preference. I have never done it and not experienced any problems. That is, as long as you keep it out of the inlets. Some very talented builders like to neutralize and other equally talented ones don't.

 

[Mtgelaude]

I have not tried any of it on wood so far, but will take pictures and post them here when I do. I’m going to clean up and sand some curly maple and test it out after I let the stuff brew for a week or two.

 

[Comfortably_Numb]

I'm no chemist. The product sold as aqua fortis will turn your gun nearly black inside of a year if you don't neutralize it. The stuff kibler sells is color stable and does not need neutralized.

 

[longcruise]

I re invented the aqua fortis wheel several. It wasn't worth the time and effort, IMO. Nitric acid is not something that you want around the shop. I got rid of the whole mess and use this. Lab Grade Ferric Nitrate, 100g for sale from The Science Company

Easy to work with and as far as my experience shows, relatively benign. I use it mostly on maple in bows where the wood is sometimes under fiberglass and there has been no problems with it.

The response seems to vary from one piece of wood to the next depending on the wood chemistry.

 

[Capt. Jas.]

I recommend saving some back as is and trying it as just aqua fortis and water. Also give it a whirl on English and even try black walnut.
Here is a sugar maple stock with only an aqua fortis/water mix thats over 20 years old with no neutralization.

 

[Mtgelaude]

Here is the first test. Nitric/water, the right section is two coats, fully dried and blushed in between, the left is one coat and covered in beeswax. Not the best finish, but I had some on hand and it was quick to give me an idea. I don’t have any finish yet, probably going with tried and true, or chambers but not set on anything for sure. Pictured in the sun, and in the shade outside. I tried a second coat to see if I could darken it up, I see no discernible difference between the two. I did not put a lot of prep into the wood I’m using to test, I sanded it to 200 or 300 grit, raised the grain, and sanded it again. Maybe more work on the surface, or a different finish will give me more contrast, but there is not a lot of pop to it right now. For giggles I might try a piece with several coats, as in four or more, just out of curiosity but I don’t think it will change the color much if at all.

So far I like the color, i will try to go a little darker, some red or yellow dye over top.

Well I’m waiting for the iron to brew for about a week, I’m going to play with a few dies over top of new sections of the scrap wood. I think I have some TransTint laying around.

Capt. Jas, that is the picture I was referring to in my previous post. Love the contrast between the curl, and the color not so dark. It’s lovely. Depending on my mood, I prefer rifles with a nice red hue to them, but sometimes I appreciate the light colored ones like the example you use.

Also, full disclosure, I would not have done any of this except that my dad made jewelry and has had a huge bottle of Nitric Acid Sitting around forever. Luckily it is in glass, and I don’t have to worry about a plastic container going bad. Crazy stuff.

 

[Comfortably_Numb]

un neutralized aqua fortis 25 to 30 years old

 

[Mtgelaude]

Comfortably numb, that’s a shame. Waste of good wood.

 

[dave_person]

Hi,
Jim Kibler sells tannin powder that can be dissolved in water and painted on the stock. Nitric acid reacts with tannin creating darker colors. It can help bring out more contrast between the light and dark figure. Also painting the wood with stong black tea will also add tannin but not as efficiently as the powder.

dave

 

[Col. Batguano]

when mixing the concoction just remember; "acid to water, just like you ought'r"
You might get a nasty surprise if you do the reverse.

 

[Codger Craig Wilcox]

Or Triple-A : Always Add Acid.

 

[Scota@4570]

I was a chemist for 30 years.

I recommend using ferric nitrate crystal and water. Places that make it for you call it "aqua fortis". For the quantities that most of us use it a good idea to by it pre-prepared. No special precautions or neutralizing is necessary.

The old chemical name for nitric acid was "aqua fortis". Nitric acid is nasty stuff. Strong nitric acid will eat holes in your clothes, burn your skin and possibly blind you if you get it in your eye. The fumes will rust your tools. Osha approved ventilated acid storage cabinets become very rusty in a few years. Most acid container caps will get brittle over time. Residual acid in home made stain may rust your gun. Neutralizing is a good idea. Making ferric nitrate solution from iron and nitric acid is a pointless and potentially dangerous.

 

[Mtgelaude]

so, a small update on the experiment. I’ve stained the same wood 5 more times. In order, after the two original sections, I have

-Nitric/water but topped off with mineral oil then beeswax.

- the next two dark stains represent one with degreased steel wool, which is a relatively clear but brown liquid, and a section with decorative iron nails dissolved. The nail batch is really muddy, but I’m not sure if that’s a problem, and I’ll try filtering it out and see what happens.

-Second to last section is Nitric/water, but with a strong batch of tea used on the wood in an attempt to darken the curl. Kinda failed to give me more contrast, but the actual color is not bad. My only complaint on this is the curl is a little bit darker, but it has a purple/red tone. Not sure how to make it dark brown or black.

- last section is the easiest of the set. Ferric Nitrate crystals, in a 5-1 mix in water. No muss, no fuss, but a nice color.

All of these were covered with beeswax after. I have some stains on the way and will try top coating over some of the concoctions later

Capt. Jas,
How did you get the contrast between the curl like the picture you posted? Was it just that particular piece of wood?

 

[Capt. Jas.]

so, a small update on the experiment. I’ve stained the same wood 5 more times. In order, after the two original sections, I have

-Nitric/water but topped off with mineral oil then beeswax.

- the next two dark stains represent one with degreased steel wool, which is a relatively clear but brown liquid, and a section with decorative iron nails dissolved. The nail batch is really muddy, but I’m not sure if that’s a problem, and I’ll try filtering it out and see what happens.

-Second to last section is Nitric/water, but with a strong batch of tea used on the wood in an attempt to darken the curl. Kinda failed to give me more contrast, but the actual color is not bad. My only complaint on this is the curl is a little bit darker, but it has a purple/red tone. Not sure how to make it dark brown or black.

- last section is the easiest of the set. Ferric Nitrate crystals, in a 5-1 mix in water. No muss, no fuss, but a nice color.

All of these were covered with beeswax after. I have some stains on the way and will try top coating over some of the concoctions later

Capt. Jas,
How did you get the contrast between the curl like the picture you posted? Was it just that particular piece of wood?

That work was by my friend and mentor Jim Hash. The wood is an exceptional piece of sugar maple.

 

[French Colonial]

That work was by my friend and mentor Jim Hash. The wood is an exceptional piece of sugar maple.

You knew Jim Hash and have one of his guns?

You are a lucky man, Jim was an exceptional person and a joy to know.

 

[Capt. Jas.]

You knew Jim Hash and have one of his guns?

You are a lucky man, Jim was an exceptional person and a joy to know.

Jim was a neighbor and one of my closest friends since I was a young teen. I have several rifles he built for me.
If we weren't planning to see each other during the day we usually talked by phone about 8am which was usually about half a days work done by then ; )

 

[French Colonial]

Jim was a neighbor and one of my closest friends since I was a young teen. I have several rifles he built for me.
If we weren't planning to see each other during the day we usually talked by phone about 8am which was usually about half a days work done by then ; )

Same here, I would call Jim to discuss something that would take 5 minutes and it would last 5 hours.

The world lost an amazing person that had a multitude of talents when Jim passed, I wish I could call him up again.

 

[HSmithTX]

Try tannic acid to turn that red/purple to black/brown. I bought mine from Jim Kibler. Put the tannic on, let it dry, then nitric and let it dry, blush with heat and be scared because it turned black. Rub it back with some scotchbrite or 320 paper to the color and contrast you want. If you want dark brown a single coat of tannic acid mixed as heavy as the water will allow, if you want black do a couple applications of the tannic acid before the nitric.