Removing chrome-plating??

[KizuKazu]

I have a katana by one of the best Gendai kaji but some fool has chrome-plated it. It was not an obvious plating. I don't think the plating stuck as it should have, it looked more like fine spider rust, as I have had another fine katana by a top smith with horimono that had also been chome-plated but that was obvious. It was "all shiny and new" looking. Uggh.

 

It was polished out in Japan. Unfortunely, it wore down some very fine horimono during the process, more I believe than would have been neccessary in a polish had it not been chrome-plated.

 

I was recently told by another collector that chrome-plating may be chemically removed without disturbing the underlying polish. He was going to get back to me with the chemicals to use but never did. He is a seasoned collector and knows his stuff.

 

Does anybody know how I may remove chrome using the correct chemicals? I have searched the Web, discovered a range of different suggestions but nothing I would be confident to try on a good blade.

 

Appreciate any help.

 

KK

[Stephen]

KK

 

You dont do it you take it to a plating company and have them do it, warning in all likely hood it will just leave a dull patina...DO NOT let them dip the nakago as it will lose all its patina, for the bother it must be something special IMHO

[Justin Grant]

Chrome can be removed with the electo-chemical process (sort of a reverse of how it is applied), but I don't know if a "polish" would last in the same process. The chemicals are not friendly.

 

I have had some parts chromed and had some that were "un-chromed" and they were fine. Expensive.....

[Mark]

i have had a sword "un-chromed" the chrome came off but the sword was damaged as it had been sanded and roughed up before being chromed, the company that did the work for me said usually the item is sanded before being chromed to remove contaminants and to make the surface rougher so the chrome sticks well

[KizuKazu]

Thanks guys. A panel shop I guess. Makes my skin crawl to think of the association but I'll outline the case and quiz them on the pitfalls. As I said, I don't think this is a pro job, as even having had a chrome-plated blade, I didn't recognise it as being such.

 

The finished product is anything but shiny so hopefully that's the result of not preparing the blade properly. What are these people thinking? I find old Kamakura swords in almost perfect condition from other Vet's. I just found a sword with gaku mei and kanji all over both sides and the mune of the nakago, in full civillian mounts with family mon on all kodugu, tsuba and the perfect original urushi saya under the leather combat cover. It was hitatsuta and looked shinshinto but the most perfect, intact and well-preserved piece I have ever found from a Vet. I've had pieces in such condition that came from Japan as souveniers from occupying forces but not from the field.

 

The old vet, a wonderful gentleman who personally received it from the Japanese officer turned out to be a distant relative.

 

Then his son stated that he wanted the sword. Damn.

 

The sword of the original posting is a heafty Nakano Kazunori. He won 1st seat at the 1941 Exhibition.

 

Thanks guys.

 

KK

[Ian B3HR2UH]

Hi Simon, I think it might be me who was to get back to you.

Thirty years ago I purchased a wakizashi signed Kazusa Suke Fujiwara Kaneshige which had a gold inlaid cutting test by Yamano Hisahide dated 1666 . The whole thing had been chrome plated including the tang.

My mother who is a qualified Metallurgist was working at the time for Sidchrome the tool manufacturers . We talked about the problem and my recollection of what I did was this

It appears that prior to being chrome plated the sword would have been given a copper and / or nickel strike which I take to be a light copper or Nickel coating that is applied to the surface prior to the chroming.

There is no chemical to dissolve the chrome which has to be polished off or taken off with acid. I made up a tube which was filled with acid and put the sword into this for a very short time . From memory just a few seconds . This removed the chrome but not the coppper/nickel strikes .Readers will probably be shuddering at this point. The acid was then washed off in water .

After this we put the blade into another container of chemical which was to dissolve the copper and nickel . After a few hours this is exactly what happened . I had been fearful that the gold would also dissolve but it wasn't touched.

The blade came out in remarkably good condition . The rust patination on the tang was pretty much gone ( whether due to the chemicals or to cleaning prior to plating I can't say ) but it has since repatinated nicely. It is impossible to know what condition the blade was in prior to plating but after it had been treated as above you could still make out the hamon and the steel had not been etched or otherwise obviously affected . I feel it came out of the treatment in pretty much the same condition it had been in prior to the plating .The treatment involved no loss of metal and the blade is now in a condition where it can be restored and papered which could never have occurred had it remained plated.

All these years later I have no idea what the chemicals used were but I am sure someone at the university metallurgy dept could point you in the right direction. Hope this is of use

Ian B

[KizuKazu]

Ian, Thank you.

 

Coincidental that your sword had a gold cutting test. My prior chromed blade was a Kotetsu with a gold inlay cutting test by Yamano Kuemon Nagahisa. I believe he was the sword tester for the Tokugawa Shogunate. The gold in my Kotetsu cutting test was lost during the process.

 

The process scares me but I believe that the blade is worthy.

 

I've seen many opinions and advise as to methods of removing chrome on Web searches but none were concerning Japanese swords. Almost all concerned auto parts where the base metal was of little concern.

 

I just have to find the name of the chemicals, or as others have suggested, take the sword to a chrome specialist, after somehow safeguarding the nakago.

 

We must catch up. I have some more swords for you to see.

 

Thanks Ian.

 

Simon

 

Hi Simon, I think it might be me who was to get back to you.

Thirty years ago I purchased a wakizashi signed Kazusa Suke Fujiwara Kaneshige which had a gold inlaid cutting test by Yamano Hisahide dated 1666 . The whole thing had been chrome plated including the tang.

My mother who is a qualified Metallurgist was working at the time for Sidchrome the tool manufacturers . We talked about the problem and my recollection of what I did was this

It appears that prior to being chrome plated the sword would have been given a copper and / or nickel strike which I take to be a light copper or Nickel coating that is applied to the surface prior to the chroming.

There is no chemical to dissolve the chrome which has to be polished off or taken off with acid. I made up a tube which was filled with acid and put the sword into this for a very short time . From memory just a few seconds . This removed the chrome but not the coppper/nickel strikes .Readers will probably be shuddering at this point. The acid was then washed off in water .

After this we put the blade into another container of chemical which was to dissolve the copper and nickel . After a few hours this is exactly what happened . I had been fearful that the gold would also dissolve but it wasn't touched.

The blade came out in remarkably good condition . The rust patination on the tang was pretty much gone ( whether due to the chemicals or to cleaning prior to plating I can't say ) but it has since repatinated nicely. It is impossible to know what condition the blade was in prior to plating but after it had been treated as above you could still make out the hamon and the steel had not been etched or otherwise obviously affected . I feel it came out of the treatment in pretty much the same condition it had been in prior to the plating .The treatment involved no loss of metal and the blade is now in a condition where it can be restored and papered which could never have occurred had it remained plated.

All these years later I have no idea what the chemicals used were but I am sure someone at the university metallurgy dept could point you in the right direction. Hope this is of use

Ian B

[bluboxer]

Hello Simon,

as you described the appearance of the plating it may be only a layer of nickel applied to bare steel.The final chromium layer may not have been applied as well as no copper base.

I am also aware of "hydrogen embrittlement" issues when hardened steel is chrome plated.If the blade was not heated and soaked at a temp of approximately 190-200 C then hydrogen from the electrolysis will remain within the steel's molecular matrix.This means it will crack and break like glass .

I would never use a blade that I knew had been chrome plated!!!

Just my op.

[KizuKazu]

Alan,

 

It does have a cracked appearence over the chrome. That's why I assumed it was some kind of minor spider rust. My Kotetsu survived having been chromed and was commented on as being a remarkable blade by the Japanese togi.

 

I requested that he repatinate the nakago and refill the cutting test with gold, paid extra for this but when I got it back, this had not been done. Bloody annoying.

 

I'm working up the courage to take it down to a panel shop or a chroming specialist. I haven't even searched the yellow pages yet.

 

I gather you study kenjutsu or Iai? What style?

 

Simon

[bluboxer]

Simon,

the problem will lie beneath the chrome.The flaws you see in the chrome are just that.My understanding is the hydrogen is just within the surface of the steel and only serves as a propagation site for cracks, therefore a good polish could theoretically restore it's functionality.

The question is: did the blade get the proper post heat treat after the chrome (common practice within automotive applications)? Further tempering (in effect) and soaking at the aforementioned temperature will most likely soften or eliminate the hamon and soften the ha. So if the hamon is intact we could infer that the heat treat was skipped and the blade should receive a good polish. A togi might be able to feel the difference and know when he has reached clean steel.

I would really like to see the kotetsu if you would be so kind as to post a photo or two.

No I do no formal practice but we have many on the forum that are highly skilled swordsmen.

Cheers

[KizuKazu]

Alan,

 

This is so much more complex than it was wth the Kotetsu, which was sold by the way in 1985.

 

The Kotetsu was obviously chromed. I knew that when I bought it off a guy who found it as the sole item in a destered shack in the middle of the Australian desert. Go figure.

 

Because of the thin nature and cracking appearence of the hada on this sword, it didn't click that it was chromed. It looked completely different than the Kotetsu. As stated, it looks more like spider rust and the blade does not have the extra niku of a proper chrome plating. I'm hoping it was done half-assed.

 

I'm going to take it down to a panel shop and talk - only talk at first.

 

Thanks for your help.

 

Simon

[johnb]

Maybe these guys are worth a call...they do guns. I know it sounds strange but the may be more "sensitive" than the guys from a panel shop. http://elitecustomguns.com/

 

JohnB

[KizuKazu]

Dear John, Thank you for your thoughts, but I am in Australia and these guys look to be in the USA.

 

Then again, you look to be somewhere between Australia and Indonesia??

 

Whatever your location, thanks for the thought.

 

Simon

[johnb]

Ah, I though you were in the states. Most chrome platers have closed their doors in Sydney, due to toxic chemicals and government regulations. I assume it's the same across the country. Good luck with your mission. Be interested to see the results.

 

John

[KizuKazu]

Ah, I though you were in the states. Most chrome platers have closed their doors in Sydney, due to toxic chemicals and government regulations. I assume it's the same across the country. Good luck with your mission. Be interested to see the results.

 

John

 

John,

 

Australia and Indonesia? I have spent a lot of time in Indonesia but was never able to turn up a sword. Saw a good Gendai when I was in Bali December '94/Jan '95, but preoccupied and had a number of very good blades with me. Dang, I should have got it.

 

Where are you John? I left some good swords in Perth. I have a black mask, grappling hook, glass cutters, gloves, thought we could catch up next time I am cleaning somebody's chandeliers.

 

Simon