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Rusting Question


tsterling

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Quote from Phil."The piece must be thoroughly neutralized with either bicarbonate of soda, or sodium hydroxide (my preference, as there is no fooling around)"

 

Thanks Phil,

 

I think I'm going to do it this weekend, I have Bicarb in the cupboard to this works for me. How much should I use, in say a small pot? I noticed you made a point of sodium hydroxide being prefered. Can I ask what the advantage is of this over the Bicarb. And if I may be so bold "how much of this would you put in the pot?"

 

Sorry for all the questions guys, just don't want to bugger it up.

 

Cheers Glen.

 

Hey Mikemc, thats a nice looking tsuba, If thats your test piece I will love to see the one your working on.

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Hi Glen

 

As soon as I get through the basic outlines that I am working on, I will post a picture, I am going to try two methods of decoration on the tsuba, one part of the design will be pierced (Sukashi) and the other part I am going to try and be a little more adventurous and inlay :rolleyes: this (still working out the second part of the theme). Have to re-read 'Fords Sen-zogan' tutorial a couple of dozen more times for it to sink in

 

Until then good luck with your own venture

 

Regards

 

Mike Mc

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Hi Glen,

 

The main advantage of the sodium hydroxide is that it works really well to nutralize acidic residues. The main disadvantage is that it is a highly dangerous and corrosive chemical. If you want to use sodium hydroxide, I usually use a 5% solution of sodium hydroxide added to water (weight to volume, eg 50 grams NaOH in 1 litre of water) Note, it is very important to add the chemicals to the water, (cool water) to avoid a potentially dangerous reaction, and wear rubber gloves and eye protection. Mix in a heavy plastic or stainless steel container, as the mixing will generate heat that can crack the glass. Even a weak NaOH solution can literally dissolve skin!!

 

I usuall use this solution because I have had a fair bit of training in chemistry and chemical safety, and am comfortable working with chemicals. If you are the least bit nervous about handling chemicals, or don't have tthe proper safety equipment, or if you want to avoid all the danger, I would suggest the bicarbonate solution. It is a more friendly solution, but not quite as agressive. Ford would probably be the best to advise on concentration, but I would suggest a 10% solution, weight to volume.

 

Both solutions should be thoroughly washed off afterwards, and well-dried. Boiling water works well, as the heat aids in the drying, but it can affect (darken) the color of the patina.

 

Phil

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Ta Phil,

Think I'll go with the bicarb, sounds a lot safer. The darkening of the patina is what I'm after. I want them to look like anatique Japanese fittings, almost black is what I'm going for. Frank, my stepfather made some fittings and also used bronze inlay, he did all the steps except for the bicarb bit. He just boiled in green tea because thats what I told him to do. I thought the tea would neutralise the rust. They came out nice and black, but as I have said before they have developed a powdery surface that gets all over your hands. Might try brushing them off with a tooth brush and applying Renessance wax. They are already mounted to a sword so we can't get the kashira off without cutting the silk ito handle wrap off. I think I'll keep a closer watch on my fittings for about a week before I even think about mounting them.

 

Thanks all for your input, without your help I would be boiling blind.

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Always wise to keep an eye on it for a while afterwards.

 

Again, I should say that I have no experience with Ford's solution, or Japanese patinatina colors. My experience comes from duplicating European finishes, which are usually even shades of deep reddish to dark brown, or grey, and very tough-wearing.

 

Best of luck!

 

Phil

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Thanks Phil, Ford, and all

 

Finnished the fittings last night, I simmered them in Bicarb for about 30mins then green tea for a further 30mins. It seems to have worked well. Will keep an eye on them over the next week. The trunk turned out a bit more abstract than I wanted but over all I'm happy with my first attempt. Might add some silver to my next fittings to jazz them up a bit more.

Blackening%20Sword%20fitting%20finnished%20002%20small.jpg

Blackening%20Sword%20fitting%20finnished%20003%20small.jpg

Blackening%20Sword%20fitting%20finnished%20006%20small.jpg

 

There is still some staining on the bronze here and there that I will have to work at getting off.

 

Thanks again to the carving path for getting me through this.

 

Cheers Glen.

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I think I suggested this method before. It's not ancient but I just was playing with the idea. The knife is a file and the guard is mild steel. As I stated before, I used a torch and rapidly cooled the heat with WD40. Nice shiny black, permanent patina. Give it a try.

(P.S. The squiggly lines are in the reduction and cropping of the photo. Not on the actual piece).

post-1558-1186875264.jpg

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  • 1 month later...

Cop-out solution

 

I recently bought some "Japanese Brown" patina from http://www.sculptnouveau.com/patinas.html. I gotta say, it's really easy to use, compared to the hydrogen peroxide+salt+vinegar dip I've been using. I don't know what's in it, but the patina just sticks and doesnt flake off. However, the difference is that the patina is not "crusty" at all, it only changes the color of the steel surface without giving it an aged texture.

 

This can be good or bad, depending on your look. The Sculpt Nouveau may be leave too smooth a look. I like a little bit of texturing, but not some of the deep pitting that's happened with the H202/Vin/NaCl dips. I think a good way to control the patina would be a two-pronged approach: use the H202/Vin/NaCl mix to create a nice rough texture, and if there is still any bare steel, brown it with the Sculpt Nouveau. I've attached three pics, one is just the Sculpt Nouveau, one is a good H202/Vin/NaCl (textured, no pits) and one shows deep pitting from H202/Vin/NaCl.

post-1626-1190421155.jpg

post-1626-1190421164.jpg

post-1626-1190421173.jpg

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Guest ford hallam

Hello Brian,

 

I like the way you are thinking with regard to working up a patina. this is probably "the secret" to creating a convincing finish like this that has depth and character.

 

There is something you said though that I think is very important to comment on so the following is not aimed at you but is intended to provide a broader view of this subject.

 

If the patina you create on iron or steel has a texture then the chances are that you have clumps of active rust there. These are very difficult to passivate and will in any case rub off. The appearance of age you are alluding to is either genuine corrosion or a very skilfully carved and worked finish. This confusion over the 2 seems to be a common misconception. This is probably why people with little exposure to fine examples of iron patination assume that these things are "all a load of old rusty iron" :)

 

What I am saying is that the final finish of the iron is down to the artist not the accidental effects of active rust. The ideal patina does not hide the nature of the finish, it merely provides colour, tone and adds depth.

 

I realise that some of my comments regarding Japanese processes, particularly of late, have been very specific and may appear to suggest that this is all beyond the reaches of contemporary amateurs. This is not my intention at all. What I hope to point out is that here we are attempting to emulate the achivements of remarkable artists who were part of an continuous tradition which goes back over 1000 years. Instant products labelled "Japanese Brown" reduce this to a tiviallity and utterly miss the point of what these men were striving for.

 

It is, of course, up to the individual to decide what it is they want to do or persue, however do I feel a certain responsibility to speak for my adopted tradition. There is a profound depth to the achievemants of the artists and craftsmen of this tradition and I firmly believe we can learn a great deal by seeking what it was they were seeking. Trying to find easier, or quicker ways of doing what we imagine ( inaccurately, as is often the case ) they did without any real understanding of the authentic process will only lead you off at a tangent to the real deal, so to speak.

 

As I conceded earlier, it is a personal choice as to what route you follow, I am merely trying to ensure that there is no misunderstanding as to what is being done.

 

We all have to start somewhere and I well remember, long before the internet and working in complete isolation, trying vainly to get any sort of colour on my early attempts. I hope that by being a bit pedantic at this stage I might be able to help some of you avoid persuing ultimately fruitless avenues of exploration. I realise that I should therefore provide a bit more practical material in this respect and will do what I can to provide some form of tutorial on the whole subject as soon as I am able.

 

Namaste, Ford

 

p.s. I see I've already made mention of the matter of the rust forming a crust here in post #8

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Thanks for the advice. I know this is a quick/cheap solution, hence the title. Once I get a real workshop of my own (i.e. not my apartment) I'll buy liver of sulfur, muriatic acid and try the mix you suggested. My friend just gave me some old green tea to neutralize active rust, I've been so far only been boiling the pieces in baking soda solution. Is the tea/baking soda the best way to control the "pitting without blackening" problem?

 

Thanks again,

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