Chemistry Question Long John

[Paddlefoot]

I guess everyone is about tired of the vinegar iron stain stuff but it still amazes me how we get such different results with it. I just had an interesting development with the 6% vinegar. I put a cast iron finial from a fence in it and the stuff started fizzing like you would normally expect. This was in a glass mason jar with the lid on it but not tightened. Loose enough to allow pressure to bleed off. It fizzed for about 36 hours but never took on a brown color, just flakes in the bottom of the jar. Being curious I put some of the clear vinegar on a stock blank and got a medium brown color. I was expecting the usual clear but turning dark blue-grey. The real kicker was that when I went back to look at it after it dried. The solution in the jar had turned a dark chestnut color and was foamy on top where it had been almost clear before. That solution makes an even nicer walnut brown color on the wood. Could this be a result of exposing the solution to open air when I uncapped the jar? What ever the reason I thought some might like to know since this allowed the stain to be ready in a couple days instead of weeks or months.
The stuff I made using a rusty Lodge dutch oven for the iron still looks like $#@* several weeks on.

[KentSmith]

I am not Long John but cast iron is a bit of a misnomer.   It is an alloy of iron and  a variety of additional elements used for various reasons,  manganese, sulfur, nickel, graphite.  I wouldn't use it as a basis for any iron nitrate stain unless you enjoy surprises.

[Paddlefoot]

I would think the same would be true for steel. Particularly cheap stuff without much need for specific qualities. What you say does seem to be true though. These "cast iron" fence parts seem to give consistently good results while the "cast iron" lodge dutch oven never seems to do well. I know that Lodge makes a big deal out of the quality of the iron they use too. I guess they just don't know I'm trying to make stain out of their cookware.
I do hope some of you will get something of value out of this though since it seems that the 6% vinegar is able to get us a stain pretty quickly compared to the 5% and steel wool. It's making a nice medium brown after a day and a half. I'm leaving the cast finial in it even though it is not visibly working on the metal. if I get a chance to mess with photobucket some more I will post some pictures of the test pieces. I had trouble with it yesterday.

[rich pierce]

I am not sure anyone has proven that one form or purity of iron or steel works better than another for aqua fortis.  It is a common belief but folks use anything old and rusty with success like old barbed wire which is seldom pure elemental iron.  

[KLMoors]

Hmmmm, Rich's post got me thinking. I found 6 ounces of 99.95% pure iron on ebay for $10. What about something like that. It seems like 6 ounces would go a long way?

[Paddlefoot]

Wow. The finial was $1.09 at the metal supply house and I'm thinking you couldn't dissolve that sucker in 50 gallons on vinegar. Well maybe 10 gallons. You  cant see any real change in it for sure.

[rich pierce]

To enhance the speed of the reaction increase the surface area of the "iron".  Steel wool or filings or turnings all make the reaction go faster.  Any big lump will go slowly and maybe imperceptibly. 

[KentSmith]

If you use a lot of stain and therefore need to make a lot of stain and want consistency between batches the composition of your steel/iron needs to be considered.  If you find a batch you like and have enough to last a lifetime, then it really doesn't matter.

[Old Bob]

Wonder what plain old hematite would do? I've got a bunch here at the house. I've decided that I'm too lazy to build a bloomer, so it would be nice to find a use for the stuff.

[Long John]

Paddle,

I can't answer your question.  There are a lot of variables to consider. 

My guess is that allowing additional atmospheric oxygen into the jar will contribute to the formation of iron oxides.  But remember that these acid/iron stains work but carrying iron ions into the wood as part of an iron/acid salt solution.  The vinegar/iron stain uses iron acetate to carry iron ions into the wood.  The aquafortis (nitric acid/iron) stain uses iron nitrate to carry iron ions into the wood.  Then, when the acid evaporates out of the wood the iron ions acquire oxygen from the air and turn into ferric oxide. 

Iron oxides, FeO and Fe₂O₃ are slightly soluble in acids.  So you might get some brown color from the solution.  But be careful, that brown color can be suspended iron oxide.  That suspended particulate will not give you the depth of color and chatoyance of a true acid/iron stain.  I alowas decant a clear solution off my acid/iron stain crock and use that as the stain.

Best Regards,

JMC

[Paddlefoot]

Well John I guess I should just count it a positive that it seemed to make a good color when it was clear and after the shift to the brown liquid with sludge. nice that it worked up so quickly too. If I get photobucket sorted out I'll post some pics of the end result.

[Blue Dog]

I know that I am a knewbie but I have a stock that I want to refinish tell me more about this process I never heard about it before. Thanks

[Paddlefoot]

Blue Dog, If you use the search you will find a ton of information on this. Not to put you off, its a neat process and turns out some beautiful colors on maple but you have to be somewhat willing to take whatever color your material makes. Most have had good luck dissolving washed steel wool in 5% cider vinegar. That takes a long time to develop. This batch I was asking about was worked up in a couple days using the 6% "cleaning" vinegar and a cast iron finial for an ornamental iron fence. You'll have to test the solution on test pieces to see if you like the color. Also you can give it a wipe with Hydrogen peroxide and that will shift the color considerably.  Results are highly variable.

[KLMoors]

John, would using the pure iron help to give more consistent results? It seems like lots of folks (including myself) get mixed results, and I am wondering if this is due to the variable of using all sorts of different materials to gather your iron particles from.

[Rolf]

John, would using the pure iron help to give more consistent results? It seems like lots of folks (including myself) get mixed results, and I am wondering if this is due to the variable of using all sorts of different materials to gather your iron particles from.

Wood from different maple trees react differntly to the same stain.  I'm working on four curly maple pistolstocks from four differnt trees. The stain is the same but the color is a bit differnt on each stock. To get the same results you have to use the same wood. I made a pair of pistols from the same blank and they stained identical.

Best regards
Rolf

[Paddlefoot]

Just my uneducated opinion KL,  the pure iron might very well be ideal. It appears that some folks are getting good results from some pretty diverse sources of iron and its sort of a question of try it and see what happens. I know some have said its just too variable and have quit using it. I have tried the steel wool and all I ever get is blue black. It never seems to change no matter how many coats or what I do to it. I have had a batch work well with a cast iron fence finial and 5% cider vinegar, but that did take a few weeks to get up to speed. Im optimistic over this current batch because it only took two days to brew up using the 6% cleaning vinegar from Heinz and another fence finial. This stuff looked like an efferdent tablet or something had been dropped in the vinegar when the iron was first placed in it. You can see a picture on the other post on 6% vinegar stain. It had pretty much quit fizzing by 36 hours and the solution was pretty much transparent when I applied the first test application. I got a nice medium brown almost right away. Way different than the blue grey I normally get. I walked away and let that coat dry and when I got back a few minutes later the solution had turned orangy brown and had precipitated a similar color sludge onto the bottom of the jar. The color on wood became a little darker, trending toward walnut but still brown and not the blue grey. I now have four coats on the test piece and by itself it is a walnut brown color. To experiment I wiped a section with hydrogen peroxide and this brought it back to the nice honey maple color you can see on Acer's rifle in the other 6% stain post.  That's pretty much ideal for me so I will play with the mix a bit, straining the solution and adding vinegar and such to get  bit different color but Im in the ballpark anyway.