Aqua Fortis Question

[Ed Wenger]

Hey Guys...

I'm presently cooking up a batch of Aqua Fortis and have a couple questions...  I started with 70% nitric acid and diluted it to a ratio of 6 to 1.  We have an old horse drawn manure spreader rusting in the woods and last night I sawed off two of the spikes located on the rear of the machine.  Their about 3" long and about 3/8" square.  I placed one in the solution and it's still reacting after about 24 hours.  It's a nice redish orange color...

I was under the impression that the aqua fortis would "eat" the metal until becoming saturated, then stop.  Is that correct?

What do you use to filter the little pieces of crud and junk out of the aqua fortis with?  Or do you keep that in?  Guess that's three questions...  Any help would be greatly appreciated!

                               Ed

[tallbear]

Virginia
I cook mine until the reaction noticeably slows.While its working I put enough iron in so it bubbles quickly but doesn't get too hot.For me this is about 12 hours(by this time the bubbles have slowed down cosiderably) then I take all but a little piece of iron out and let sit overnight.Then I pour off all but the sludge on the bottom of the container through an old t shirt.I'm left with a dark red liquid with no particles.I keep this in a container that is not sealed tightly as the solution will work for another month and could burst the container.

Mitch

[rich pierce]

most folks use smaller finer bits of steel so it goes faster (more surface area/mass) but you'll be fine.  I do like Tallbear also.

[Ed Wenger]

Thanks guys, that helps...

                  Ed

[doug]

    I cut the acid to about 30% (I start with 95%).  I also use steel wool and put it in in several batches because the acid reacts pretty actively.  I also let the acid cool somewhat between additions and do not remove the sludge.  Most of the reaction is finished within an hour or so but I let it stand with extra iron, overnight before removing the unconsumed steel wool.

cheers Doug

[Long John]

The reaction rate is contolled by exposed surface area.  The iron spikes have far less surface area than and equivalent mass of steel wool.  I would just give it some time.  The more iron dissolved the less acid you will have to neutralize later.

Best Regards,

JMC

[Stophel]

I put in nails and little bits of scrap mild steel.  Just let them bubble away at their own pace.  Could take hours, could take days.  I do not recommend steel wool.  It reacts way too quickly.  Belching forth billowing clouds of noxious red death.  It also gets VERY hot.  Just drop in a few nails at a time and let it sit....what's the rush?

Last few times I have made it, I have gotten NO sludge at all.  Very clean, clear mixture.

[DaveL]

New to the acid blending.  I've never made my own solution, but was wondering if you need to add anything to the wahkon bay aquafortis?  My test peice looked ok, but I wasn't sure if it would take less heating if filings or steel wool was dissolved in it.
thanks,
Dave

[tallbear]

Dave
My experiance with Whakon Bay is that it's very acidic.The stuff I used was made by the original owner so can't say for sure with the new owners.I dissolved some additional iron in to mine which helped cut down the acidity.Straight out of the bottle it stained very dark which is fine if thats what your looking for.After adding some iron and decreaseing the acidity i was able to get some lighter colors,although some of that may have been useing different wood.The aqua fortis by Whakon had hydrocloric acid in addition to the nitric.Also make sure to neutralize the Whakon.I use household ammonia.

Mitch

[M.D.H.]

I've been working with making nitric ferris for a while now and have tried more "recipes" than I care to admit too.  The primary issue, that I have found, is temp control.  If it gets too hot, then you'll end up with a batch that won't produce the rich tones everyone so desires or you'll end up with sludge in the bottom. 

The temp can be controlled by three ways.  How much iron you introduce to the acid, what ratio of acid to water you use and the temp of the water/acid solution is. 

First, I won't make nitric ferris in the summer.  Outside temps get too hot and you can't control the reaction time as well as you can in the winter.  Second, use cool water in your solution.  I leave the water in the fridge over night first.  Third, surround the container you will use in an ice bath.  By using cooler components you'll slow the reaction down, and that is exactly what you want. 

When done right, you should never need to neutralize your stock.  If someone can explain how to post pics, I'll show you the results that I have come up with. 

The only part that you can't control is the wood.  No matter what you do, ever piece and even different sections of the same wood will contain more or less tannins.  They will change the reaction of the nitric ferris to the wood every time.  I've seen it on  the same stick.  The bottom is dark, the top is light.  Can't control that.