Mustard Patina

J

Jebadiah_Smith

Joined
Jul 28, 2004
Messages
878
Work got delayed until noon today, so I have time to play with my new baby. I put the satin finish on and then decided to put on a mustard patina. I covered the whole blade with a thin layer of mustard then dabbed it with my finger to make a pattern. A while later I washed the mustard off and the finish looks for all the world like wootz or damascus. What do you guys do for patinas? Do you have any tips for maintaining a patina?
 
Since i work in the swimming pool/custom concrete biz i have all kinds of access to different chemicals to experiment with. One of my favorite ways to put a deep dull grey wootz kind of finish on a blade is to soak a cloth in Muriatic acid and then wrap the whole blade with it. Let it sit for an hour then neutralize the acid with a base like pool pH increaser or some sodium hydrocarb. You have to be sure to get the acid neutralized or you'll get constant yellowy staining with some rust on the blade everytime you sheath it for any length of time. If you do it right then the cloth will kind of etch a neat pattern where it was wrapped/had more acid on it etc. Oh and you have to do it in a well ventilated area. Muriatic acid will do a number on your lungs if you breath it in, but it does a great job of taking off a heavy rust and leaving a very pretty and durable grey finish.

~Jake
 
Steely_Gunz said:
Muriatic acid will do a number on your lungs if you breath it in,
Click to expand...
No kidding!
Hydrochloric acid.

If you're not accustomed to working with chemicals,
or don't have open space to work,
Avoid It.

ditto Sulfuric acid (battery acid) !

Huge vapor cloud you can't see.
! Watch out for shifting air flow / breeze if you're depending on it for safety!
And one tiny drop splashed in an eye will do to you too.


You can try;
vinegar (5%-12% Acetic acid)
Higher concentration of Acetic acid becomes dangerous
citrus juices are popular (bottle of lemon juice)
or phosphoric acid (leaves a protective coating too)

[phosphoric acid is used in coka-cola (along with other acid)
& can be found in various cleaning products
for tarnish, kitchen, tile, brick, cement---read ingredients.
Much less danger than HCl or H2SO4,
but use care with concentrated solutions.]

Bleach (Caution!) can be used
[can also create rust, depending on application & concenntration]
or ferric chloride (caution!) directly.

~
~~~~~~~~~~~~~~
<> call me 'Dean' :)-FYI-FWIW-IIRC-JMO-M2C-YMMV-TIA-YW-GL-HH-HBD-IBSCUTWS-TWotBGUaDUaDUaD
<> Tips <> Baha'i Prayers Links--A--T--H--D
 
Search individual words here & bladesmith forum:
Try title only searches too.

patina
ferric
chloride
muriatic
hydrochloric
mustard

~
~~~~~~~~~~~~~~
<> call me 'Dean' :)-FYI-FWIW-IIRC-JMO-M2C-YMMV-TIA-YW-GL-HH-HBD-IBSCUTWS-TWotBGUaDUaDUaD
<> Tips <> Baha'i Prayers Links--A--T--H--D
 
I sanded off the patina because I wanted to play around with different patterns. I was pleasantly suprised to find that when I used 600 grit paper of the edge I brought out a clear, frosty temper (hardening) line. I had seen it when I did the satin finish, but now its clearer. Engnaths website: www.engnath.com has great info on bringing out a temper line and on other subjects.
 
That's a great site.

If you let the mustard etch go longer
it will etch the pattern into the metal.
longer=deeper

Nice effect if you want it,
be careful if you don't.
 
I also enjoy the Ethnographic Edged Weapons Resource Site forum and there is quite a bit of good info there about enhancing the contrast between the different metals in a pattern welded blade or even the temper line from the rest of the blade. They're usually dealing with antiques and quite careful.The surface of the metal has to be prepared by removing oxidation and thoroughly degreased. Sometimes the blade is warmed by leaving the blade in the sun or heating it evenly with hot water as the etching process is hastened as the heat makes the acid being used more caustic. Traditionally, citric acid from various fruits from common limes to exotic fruits not commonly available in the US are used, but they work slowly and require patience (time and skill were all they had back then). It must be applied evenly and kept wet. Good results are also available using diluted ferric chloride, which is sold by places like Radio Shack as PCB etching solution. Ferric Chloride gives a brownish tint like iodine which recedes as it's polished. I have had good results with Naval Jelly, which is acidic, and was recommended to me by Erik Farrow of Farrow Galleries. Erik and his father professionally restore art and Eric is a respected antique weapons dealer and good guy to deal with. The solution of your choice is left on for a few minutes (or longer, depending on it's strength) and removed, then re-applied if more effect is desired. When the desired result is there, neutralize the acid with a paste of baking soda and water scrubbed into the blade and polish with flitz, simichrome, etc. Too much polishing will remove the effect. Finally apply whatever you use to prevent rust. I personally prefer to bring out what is in the steel rather than to create a faux pattern, but that is in the eye of the beholder. In khuks, there is usually only a temper line to bring out and the finish of the blade will be less polished and more gray, but I think the temper line adds character and further reveals the kamis work, for better or worse.
 
Safety note; always add acid to water, never add water to acid! It pops and splatters. And a full face shield, the eyes you save will be your own! :cool:
 
Thanks ddean.

Regarding mixing acid and water, this memory device is corny, but I've remembered it since high school.

"Do what you oughta, add acid to water."
 
search for mustard for that discussion of ingredients

so we thought
but if its the vinegar,
you'd expect the thicker areas to etch deeper
in fact it's the other way around
I was surprised

~
~~~~~~~~~~~~~~
<> call me 'Dean' :)-FYI-FWIW-IIRC-JMO-M2C-YMMV-TIA-YW-GL-HH-HBD-IBSCUTWS-TWotBGUaDUaDUaD
<> Tips <> Baha'i Prayers Links--A--T--H--D
 
Thomas Linton said:
I presume that it's the vinegar in mustard that does the work, correct?
Click to expand...

If the mustard, contains vinegar the vinegar wil lhave an effect.

However, mustard formulated without vinegar, as well as hydrated washibi (Japanese horshradish) powder work also. Haven't tried it but I expect that ordinary ground horshradish would work too.

Of course, the most common mustards are formulated with vinegar, especially the least expensive, which is the natural choice for this application.

The same sulfur compounds that produce the hot taste in these condiments are probably responsible, as such substances are known to be corrosive. I think that metal sulfides are formed which then react with oxygen in the air, producing a surface coating of metal oxides, or perhaps mixed sulfides and oxides.

That may explain why the effect is more pronounced in thinly coated areas.
 
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