Experience with Aqua fortis?

[jrstegner]

Has anyone here stained a laminated riser with aqua fortis? I have a curly maple riser that I planned on staining,  but I have some concerns. How hot do you have to get the wood for it to change color? Hot enough where delamination could be an issue? Or would a hair dryer be sufficient?

[KenH]

Wow -- haven't heard anyone call nitric acid Aqua Fortis in a looong time! 

Staining with nitric acid is easy, and the amount of heat is minimal really.  You're not putting the wood in an oven for pete's sake.   Here are the basic instructions from a manufacturer of Aqua Fortis wood stain:

"First, raise the grain, by wetting the wood surface with water, and force it dry with heat. Use 0000 fine steel wool to remove "whiskers" from the wood surface. Repeat once or twice. If you do not raise the grain, compressed wood fibers will eventually raise under your finish, causing a textured surface."

"Apply Aquafortis Reagent in the same manner, and "blush" the surface to the desired color, by holding the surface over a hot surface (electric stove burner or other radiant heat source). Avoid using a concentrated torch flame, which might char the wood."

Move the stock quickly over the heat source, to blush the reagent, revealing the variations in the density of the cell structure of the figured wood. If the wood displays an olive tone at first, continue blushing the wood until the rich yellow gold browns appear. Some maple may display attractive reddish brown undertones, or this effect can be added using a very dilute overcoat of cherry stain, to create a subtle shift in color, while using Aquafortis to best display all figure." 

[Flem]

Be careful with Nitric acid, the stuff is very corrosive! Wear a half mask at the minimum. That stuff is hell on lung tissue, mucous membranes, eyeballs, etc. You can get similar effects with Ferric nitrate or Ferrous sulphate and its a lot less toxic. On the other hand you can make some interesting compounds with Nitric acid and aspirin or ammonia or glycerin or.........

[monterey]

I have used "aqua fortis" on maple rifle stocks and bow builds.  I used it on lams once and it worked out fine.  Ive made my own and recommend strongly against it!!  Most longrifle builders are now using a simple solution of ferric nitrate crystals and water.  Its not volatile or highly corrosive.   It is the easy and safe way to make your own aqua fortis.

I have some stored in a jelly jar for over a year and it is not corroding the cap or misbehaving in any way. 

You can order the ferric nitrate crystals here:

https://www.sciencecompany.com/Ferric-Nitrate-100g-P6384.aspx

[Eric Krewson]

I have used the stuff extensively, for the unfamiliar it is nitric acid with iron dissolved in it until the acid solution is depleted and won't dissolve anymore iron. My last batch of store bought stuff was sill a little acid and needed to be neutralized on the gun stock. I bought some iron nitrate solution later that was completely inert.

Neat stuff, I blush mine with a paint stripping heat gun, the surface doesn't get too hot to touch.

I used the iron nitrate stuff on the maple gizmos I have on the St Jude auction. Each piece of maple from different trees reacts differently and will stain darker or lighter.


 

[jrstegner]

Thanks guys, I just ordered some iron nitrate from Kibler's. I'm hoping for a color similar to that bottom Gizmo of Eric's.

[Eric Krewson]

I diluted the iron nitrate from Kibler because the bottle was getting low and I had a lot of gizmos to stain.

Here is it is full strength;

[jrstegner]

Very nice work Eric! I think I am going to build one of his kits this winter. I need a new squirrel rifle.

[Eric Krewson]

That rifle is a Tn rifle I built.

I built a Kibler next.

[jrstegner]

Very nicely done!

[Flem]

Had not heard of Kibler's, so I had to check them out. Holy Crap $19. for 4oz of mixed Ferric nitrate solution! I use to buy 50lbs of the dry crystals for less than $30. when I was staining cement with it. You might call around to places that sell fertilizer and see if they have any. You don't need lab grade to stain wood.

[bigbob2]

lovely work on the rifles Eric !.

[jrstegner]

Riser started to delaminate just as the color changed. Bummer, it was going to look awesome. I'm not saying it can't be done, but I won't try it again.

[monterey]

Riser started to delaminate just as the color changed. Bummer, it was going to look awesome. I'm not saying it can't be done, but I won't try it again.

Did you maybe get it too hot?  Maybe there was stress in the riser that was just waiting for some heat to set it free?

[jrstegner]

I didn't get it any hotter than I needed, just  hot enough to change color.

[Flem]

If  it was a learning experience, you should share the details. What glue did you use? How did you heat it?
How wet did you get it? etc. I'm sure everybody will appreciate the knowledge you gained.

[Buemaker]

Eric, very nice rifles.

[jrstegner]

I glued up the riser with EA-40. Cured in an oven at 160 degrees for four hours. I wiped on the AQ with a paper towel. I let it dry. Then blushed it with a heat gun on the low setting. It worked very well. The delamination occured on the glue line at the shelf. You have to get the wood pretty hot in order for it to change color. After the wood cooled it was impossible to see where the separation occured.