Sword conservation

[Roland_M]

Originally Posted by A. G. Maisey

Thanks for that Ariel, I've learnt something.

I've never used tannic acid know nothing about it.

Hello Alan,

watch out with tannic, it is not as harmless as many people claim.

If you have massive corrosion with deep pitting, tannic is almost useless and it also can ruin the surface of the blade.

Two years ago I tried out tannic on a japanese sword stick. The first attempt was very good, the hamon was very strong and clear. I gave it another try and the second result was horrible, the surface was ruined and the hamon was lost. I still don't know why.

Tannic is a good choice for WW2-pieces with relatively recent corrosion but imho nothing for your sword.

You also should know, that such a deeply corroded sword often looks gruesome after rust removal.

Tannic will be used with water and the water goes everywhere, into the smallest cavities and could make the blade more worse.

My suggestion is simple, use a creeping oil on the surface for at least one year or so and check the surface every two or four weeks. After one or two years of oil-treatment I would use sandpaper or steelwool to finish the surface.

Have you think about elektrolysis? All you need is a car battery charger a bucket and a little bit of baking soda. I already made it and I'm totally satisfied with the result. The heavily corroded japanese arrows in the picture had an electrolysis treatment. The lower part of the shaft is untreated. All you need to do is cleaning the object from time to time during the treatment. Very easy and safe. No acid, no salt and no toxic gases, just a little bit of hydrogen.

Museums often use elektrolysis for restoration.


Roland

[ariel]

Thanks folks!
Please keep going: aside from practical suggestions that becomes a valuable topic for general discussion and use.

[Lee]

I will see if I can find the instructions that I used to stabilize a Viking sword that was seriously flaking away. I suspect it is on the extracted hard drive of my dead computer.

I remember that I had to alkalinize distilled water using Sodium Hydroxide to a certain pH (11 by memory) and would then would soak the sword for a few days until pH fell towards neutral. This needed to be repeated several times for over a month. Finally, the pH drop stopped occurring. At this point I dehydrated in a series of anhydrous isopropyl alcohol baths (just like tissue in the path lab!) and then finally into acetone and then finally coated with paraloid B-72 dissolved in acetone.

This does not give a great display surface and leaves much of the rust, but it does have the advantage that it removes the inherent vice of the salts. The coating can be removed later with acetone if needed.

[ariel]

Lee,
That would be great!
Many thanks in advance!

[Miguel]

I am no expert but I was going to suggest Electrolysis as suggested by Roland. Since I read estrch`s post I have used it with great success although not on such heavily corroded items. As Roland says it is much used by Archaeologists and can be controlled so that you can remove as much or as little as you wish within reason there is plenty of info on the web for you to peruse.
Miguel

[machinist]

I am very much interested in this topic as I have a very rusted axe head that I want to at least stabilize. It is flaking apart and I think if I did the electrolysis thing I would not have much left.

I have thought about the distilled water soak followed by baking and then wax but I am learning from this thread first.

Does the paraloid B-72 provide much structural stability for a fragile item?

[ariel]

I have shown this 15 cen excavated Bauernwehr before, but think it might be useful here.
Stabilized with tannic acid.
There are commercial Rust Converters: tannin, polymer and a bit of phosphoric acid