doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Rust Blueing Help

There's still something amiss. Today I coated, carded, and recoated 22 sets, all with C.10. I'm currently carding a second time, this is my break. My house is running around 60% humidity, and even so I didn't use the rusting cabinet. Something strange is happening with your efforts.

Ken

JMH yes it is the same bluing mixture on that page but also on page 73 "Old English blue" also known as "American trade Express Browne" this is just another variation of the mix. This high Mercuric Chloride formulation was very popular and used by many Birmingham trade barrel finishers in past times. There are many reasons for this but two main reasons where one you could from start to finish rust bluing a set of shotgun barrels in less than an hour. Two you could re-blue worn blue barrel sections without completely re-finishing all the barrel set as long as the original bluing was rust based.
Yes it has high Mercury levels though simple precautions will keep its detrimental effects to a minimum. Working under cover outside of a building is the safest when bluing with this type of express rust bluing method, or alternatively having a high level of air extraction from the work place.
I have used both methods to keep the mercury vapours down to an acceptable safe level, And at 70 I am not as mad as a hatter though the lady I live with may want to say a word or two about that! Though in my defence I would say it is the Mercury Amalgam teeth fillings I have been carrying around for more years than I care to remember.

dennis potter used an a formula from that book with good results.you could contact him and ask,i have used laurel mt and brownells and another that i cant remember all will work good luck

I use Jim Baiar's (Half Moon Rifle Shop) Gun Goddess formula. Excellent results.

Rust blue ingredients/components listed on page 3.

http://www.rustblue.com/wp-content/uploads/2013/10/Rust-Blue-Multi-SDS-GHS-Rev-2.pdf

I feel that I should say that not all the relevant information on the subject of gun bluing and browning is written down even in that Bible on the subject "Angier's." Also formulas passed from person to person weather verbal or written get changed a little and it is in certain cases understandable because we are trying to duplicate formulas in some cases two hundred years old.
Lets take the original "Niedner" formula, the subtle discrepancy is in the "wire nails" because when the formula was first used nails be them wire or any other form where made mostly from Wrought Iron and not as todays, made of steel. The formula works far better if bits of wrought iron or pieces of cast Iron are dissolved in the Acid.
Now the vexing subject of "Spirit of Nitre" or sometimes written "Spirit's of Nitre", then sometimes you come across "Sweet spirits of Nitre." The first are the same chemical substance, though the third is not in fact it was a very popular druggist's medication until it was withdrawn from public use caused by a couple of unfortunate accidents. Though the one thing they all have in common is the active ingredient "ETHYL NITRITE" this is also not available over the counter for public use, because it is part of the illegal drugs scene and is known as "Poppers." Now there are a number of schools of thought about Spirit of Nitre and why it is added to vintage bluing solutions Ethyl Nitrite is so unstable that it can only exist in Alcohol as a percentage. It is there to give the mixture a pleasant smell though I am not too sure about this. Though the one thing that people are not made aware of is that very often it is included in a formula containing Mercuric Chloride, the reason for this is simple Mercuric Chloride will not dissolve properly in water YOU MUST MIX IT WITH ALCOHOL FIRST and add it to the water, I have never seen this mentioned in how to make the formula up hence Spirit of Nitre may just be included just provide the needed Alcohol and a pleasant smell! So over the years I have used high percentage Alcohol and not bothered with Spirit of Nitre and found things work fine.
Now one personal little thing I do before I started browning Antique muzzle loading guns with English "common twist" or sometimes known as "skelp" barrels, to improve the contrast between the Iron and Steel I darkened the Iron with Tannic Acid first by rubbing the barrel all over a couple of times with an Acid soaked cloth this action also works well on Damascus barrels. This darkening of the Iron gives a far finer contrast between the Iron and Steel after browning. Though I will add it does not work for all Iron types but it is such a simple thing to do so it is worth trying.

My first thoughts is oil contamination. Are your carding wheels or wire wool thoroughly decreased ?
I use ferrobronze a lot and really like it . I believe there's a point, well before the metal can pit that the rusting can remove some of the black from the previous pass. Just like putting too much solution on (too wet) can do.
Chemical quality, I get a lot of mine from that auction site so given that most are 99% pure according to the label I would suspect that's good enough. I've always wondered what the other 1% is made up of though.

Little update, I�ve tried some new test pieces and slightly better in colour but still not perfect. I really don�t think it�s the metal now and something to do with the chemicals. I have actually ordered a solution from a company here in U.K that states it�s the �Birmingham Black� formula and obtains a decent blue. I will use my original process and same test pieces and see if it works with better results. If so, I guess that�ll mean there�s a problem in my original solutions. I did get an email saying there mixing it and that it takes a few days to �wet out�. Never read that saying in Angiers book, does anyone know what that means? I�m guessing it�s to let all the chemical reactions take place before decanting down.

I degrease all my wire wool in acetone. Leave them to soak for a while then take them out and let them dry naturally. I always thought that�s enough but could be wrong.

JMH

How many cycles are you running your test pieces? The black builds slowly, on fluid steel it take typically six or so cycles before the black really deepens. You steel wool degreasing is fine, I rotate the pieces in the soak, so whatever piece I take out has been in at least 24 hours.

I let solutions set for a day or two after making them, with occasional agitation. It's not as important if all the ingredients are liquids. Using dry ingredients like copper or ferrous sulphates is a little different.

Are you using distilled water for your solutions? City and well water can both contain chemicals that can alter solutions, mainly calcium and carbon compounds, which can mess with the acidity of the solution.

Regards
Ken

I use lab grade distilled water from quite a good company here in the U.K. I�m not so sure of the other chemicals though. I�m going to see how this solution works that I ordered and go from there.

I put 7 passes on the test pieces and got slightly better colour but the rusting times are still 24 hours plus in a humidity cabinet.

JMH