Coffee Stains

rasdan · 6th June 2011, 12:28 PM

Thanks Thilo and Alan!

kai · 7th June 2011, 12:08 AM

Hello Rasdan,

Wootz and pattern welded blades can require pretty different approaches to etching. Granted, also pattern welded pieces can easily damaged by overenthusiastic staining attempts but etching wootz (especially antique pieces) is even more an art. If you really need/want to etch wootz yourself, make sure to search for similar blades (origin and age and wootz type) which are still in stain as a reference. While FeCl3 can be utilized to etch wootz this is by no means the only nor likely to be the single best approach for the majority of antique blades. There's a lot of other etchants which may be suitable or a combination of these may be needed for optimal results (quite a lot of pointers and opinions can be gathered from the net). I'd certainly recommend to try very weak dilutions first even if this needs more patience. If the wootz blade has still a nice original surface which hasn't been polished with power tools, diluted oxalic acid may be worth trying first - just a wild guess though.

Regards,
Kai

A. G. Maisey · 7th June 2011, 01:27 AM

Oh yes --- my error.

Rasdan wrote "wootz", I replied for mechanical damascus.

Sorry.

rasdan · 7th June 2011, 04:19 PM

Thanks for the pointers Kai.

I think Alan's explanation would cover wootz as well.

I am considering a few options now. Unfortunately I don't have sample blades of same origin. I am thinking of brushing a bit of citric acid on the blade to start with, but I'm not sure. I guess I'll browse and read a bit more on this area on the net. Thanks again

mrwizard · 7th June 2011, 04:50 PM

Hello Rasdan,

I don't have any wootz blades but i have frequently read that Nital is recommended for etching them. Nital is a mixture of ethanol and nitric acid. You can buy it at chemical suppliers. Don't *ever* try to mix it yoursself, if the concentration of the nitric acid gets to high it tends to explode!

Best Regards,
Thilo

rasdan · 7th June 2011, 06:17 PM

Hi Thilo,

Kaboom!! No, don't want that to happen. Thanks for the advice. It's like you can tell I'm into experimenting things.

Actually these chemical stuff is pretty hard to get here in Malaysia. There's a nutcase around KL recently goes around splashing people with acid for no reason. He is still at large. So, at the present time, I think if I try to buy any acid without proper papers, I'm certain people would give me a frighten look and dial 911.

A. G. Maisey · 17th June 2011, 07:55 AM

Rasdan I have had a conversation with a friend who is somewhat of an expert on wootz.

His advice for etching is NOT to touch ferric chloride, he claims that the chloride can damage the steel in the long term --- first time I've heard this, but apparently wootz fanatics believe it to be so.

His recommendation for etching is a 5% nital solution applied with a cotton swab for a brief period of time, starting at 10 seconds and working up.

Rinse off, kill the nital with a slurry of bicarb of soda, rinse, dry, oil.

He did comment that it would be best if the blade could be demounted and immersed fully in the solution, but he recognises that this is not always possible.

6th June 2011, 12:28 PM	#1
rasdan Member Join Date: Dec 2004 Location: Kuala Lumpur Posts: 369	Thanks Thilo and Alan!

7th June 2011, 12:08 AM	#2
kai Member Join Date: Apr 2005 Posts: 3,255	Hello Rasdan, Wootz and pattern welded blades can require pretty different approaches to etching. Granted, also pattern welded pieces can easily damaged by overenthusiastic staining attempts but etching wootz (especially antique pieces) is even more an art. If you really need/want to etch wootz yourself, make sure to search for similar blades (origin and age and wootz type) which are still in stain as a reference. While FeCl3 can be utilized to etch wootz this is by no means the only nor likely to be the single best approach for the majority of antique blades. There's a lot of other etchants which may be suitable or a combination of these may be needed for optimal results (quite a lot of pointers and opinions can be gathered from the net). I'd certainly recommend to try very weak dilutions first even if this needs more patience. If the wootz blade has still a nice original surface which hasn't been polished with power tools, diluted oxalic acid may be worth trying first - just a wild guess though. Regards, Kai

7th June 2011, 01:27 AM	#3
A. G. Maisey Member Join Date: May 2006 Posts: 7,015	Oh yes --- my error. Rasdan wrote "wootz", I replied for mechanical damascus. Sorry.

7th June 2011, 04:19 PM	#4
rasdan Member Join Date: Dec 2004 Location: Kuala Lumpur Posts: 369	Thanks for the pointers Kai. I think Alan's explanation would cover wootz as well. I am considering a few options now. Unfortunately I don't have sample blades of same origin. I am thinking of brushing a bit of citric acid on the blade to start with, but I'm not sure. I guess I'll browse and read a bit more on this area on the net. Thanks again

7th June 2011, 04:50 PM	#5
mrwizard Member Join Date: May 2010 Location: Dortmund, Germany Posts: 102	Hello Rasdan, I don't have any wootz blades but i have frequently read that Nital is recommended for etching them. Nital is a mixture of ethanol and nitric acid. You can buy it at chemical suppliers. Don't ever try to mix it yoursself, if the concentration of the nitric acid gets to high it tends to explode! Best Regards, Thilo

7th June 2011, 06:17 PM	#6
rasdan Member Join Date: Dec 2004 Location: Kuala Lumpur Posts: 369	Hi Thilo, Kaboom!! No, don't want that to happen. Thanks for the advice. It's like you can tell I'm into experimenting things. Actually these chemical stuff is pretty hard to get here in Malaysia. There's a nutcase around KL recently goes around splashing people with acid for no reason. He is still at large. So, at the present time, I think if I try to buy any acid without proper papers, I'm certain people would give me a frighten look and dial 911.

17th June 2011, 07:55 AM	#7
A. G. Maisey Member Join Date: May 2006 Posts: 7,015	Rasdan I have had a conversation with a friend who is somewhat of an expert on wootz. His advice for etching is NOT to touch ferric chloride, he claims that the chloride can damage the steel in the long term --- first time I've heard this, but apparently wootz fanatics believe it to be so. His recommendation for etching is a 5% nital solution applied with a cotton swab for a brief period of time, starting at 10 seconds and working up. Rinse off, kill the nital with a slurry of bicarb of soda, rinse, dry, oil. He did comment that it would be best if the blade could be demounted and immersed fully in the solution, but he recognises that this is not always possible.