Tarnishing metals

[edispilff]

Does any one know of a tried and true method for fast tarnishing/"antique styling" of metal rivets and screws? Just got my AL, brass and copper hardware in, and it appears to be in direct competition with a mirror as far as reflectivity goes... and that is far too bright to match up with the dark leathers.

Right now i've got one of each sitting in saltwater, in saltwater and vinegar, and thinking of something else which could speed the look to old.

Any suggestions are more than helpful.

EDIT>>>

Found these recipes for a good tarnish setup, but my shop isn't located anywhere near a place i can get these... working on trying to extract/make the necessary compounds to create these mixes...

quote>

Black for brass:
2oo gm cooper carbonate
1 lit ammonia /
25%/ Cold immersion!

Brown for brass:
5 gm cooper sulphate
5o gm potassium permanganate
1 lit water Hot immersion(9o C)!2-5 min.

Yellowishbrown to orangered for brass
100 gm cooper sulphate
5o gm sodium chlorate
1 lit water Hot immersion (9oC)!

Goran Budija
- Zagreb ,Croatia

<quote
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EDIT part 2>>>
OK, got a fairly quick fix for making brass, aluminum and copper from shiny new to not-so-shiny old It works! Results may vary from country to country. Void where prohibited. Somwe restrictions may apply. Not responsible for personal injury. Yaditah yaditah yaditah

BTW This stuff is not particularly dangerous to skin.. but i wouldn't suggest drinking it, washing your eyes out with it, or soaking your feet in it for extended periods.

What you'll need:
-about 1/4 can of coca-cola (or something similar with phosphoric acid in the ingredients)
-about 50 ml of hydrogen peroxide (at least 3% solution; 7 is better)
-about 4 tablespoons of salt (lets just say 30 grms)
-about 45-50 match sticks (make sure they smell sulphury [like rotten eggs] when you light them)
-about 20 cm of the thinnest copper wire strands you can find
-1 pint glass container or thereabouts (remove beer residue first )

What you need to do:
1. crush the match heads in a piece of folded paper using the back of a metal spoon
2. throw away the match paper/wood and pulverize the heads into a powder
3. set match powder aside
4. cut the copper wire into small pieces >2mm
5. set copper wire pieces aside
6. pour the coke into the GLASS container
7. add the salt to the container
8. add the hydrogen peroxide to the container
9. put the container in your microwave or heat it very carefully to a hot, but not boiling temperature (roughly 1.5 minutes). hot being the point right before the small bubbles form on the bottom of the glass
10. remove container and add the crushed match heads and the copper wire pieces
11. stir vigorously for about 2 minutes
12. add your shiny objects and stir
...continue to stir everything up every 5 minutes to keep too much settling from happening. Keep the objects in their for about 20-30 minutes or until satisfied with the result.

This will take the shiny right off and add a frosted dirty finish to brass and aluminum. If your match sticks are red, be careful, it can actually change the color of brass to a more orange/lt. red color (make sure the match heads are fully dissolved). The longer you let the mixture sit, the stronger it will become. So, keep a loose lid on it and set it in the window sill for a couple of days, and you'll be able to divide the time necessary to tarnish away. Remember to wash the objects off thoroughly with clean water when finished. This stuff will continue to eat away if left on.... If you would like an even stronger tarnish, get some dirty hands on that finished metal, and do the satin rub .

AL will take less time to work into a tarnish than brass. Am working on a tarnish for nickel next.. will addend to this post.

Good luck and please let me know how this (if you ever should have a need for it) works for you

 

[jojo]

Oh, I am going to have to try that! All those bright yellow buckles I have could do with toning down! The thing is, does the lacquer they are covered
with prevent your magic potion from working?

I used a blow torch on one buckle the other day (in desperation ) that probably removed the lacquer, thinking of it!

 

[Mike Ameling]

For "aging" iron/steel, just use household bleach. You will be amazed at how fast it will rust/pit metal. But it also ... stains ... the iron instead of just rusting it. That "stain" then makes it look like the iron on old farm machinery that has set out in the grove for decades.

Just dip in bleach, and set aside in a damp environment - like in a plastic bag on a damp paper towel. Check it every day or so to see how it is progressing. And wet it down with bleach any time it gets dry. Then let it get as ... old ... looking as you want it to.

When it looks tarnished/stained enough, wash thoroughly to remove the bleach. And then give it a light coat of oil to stop or slow down any further rusting.

A lot of newly made "old Indian artifacts" were made this way - because it actually "stains" the metal. If you wipe off new rust on new iron/steel, you still have new shiny metal beneath.

Or press those screws/rivets down into a freshly cut potato or onion, or wipe them with it. That will also stain normal carbon steel. A friend had just gotten a new carbon steel custom knife with a mirror polish on the blade. His wife used it to cut up some vegetables for the evening stew when out camping. She did wipe the blade off afterwards on her apron, but nothing more. A couple hours later the blade was well "darkened". She thought he would be very upset with her. Turns out he was going to do the same thing - to take that "shine" off of the blade.

Stainless Steel has lots of Chrome in it specifically to slow down any rusting/tarnishing. It takes a whole lot longer to work on them.

Any time I want to "age" some brass or copper, I just take a little blackpowder mixed into a paste with water and wipe it on the pieces. The saltpeter/charcoal/sulfer in the blackpowder do a very good and quick job of "tarnishing" the brass/copper. It's mostly that saltpeter (potassium nitrate). Soaking the parts in urine will do the same thing - because of the saltpeter in it. Soaking iron parts in urine also works well, but does take a lot longer to work.

Just a few humble rambling thoughts to share. Take them as such.

Mikey - that grumpy ol' German blacksmith out in the Hinterlands

 

[spamel]

A note of caution when crushing the match heads: Do them a bit at a time, not all at once. A mate did that once and nearly took his face off! He used it to launch metal ball bearings from his phosphor bronze cannon that he made as part of his trade training as a Fitter Machinist.

 

[edispilff]

UPDATE!!!!

Yes, mike.. you are spot on with the gunpowder technique.. except here in the states, its hard to find blackpowder that isn't that new smokeless kind that the DEA regulates. If you can get your hands on some cheap chinese firecrackers, those have just the right stuff... And again, safety first... no banging match heads with your firesteel, and no lighting firecrackers in the kitchen!:yikes:

Soooooo, went throught he cabinets and found a few other things that may help with the tarnishing solution.. and damn if i didn't discover how to acid etch Colors into metal! Almost any metal.. even chromes (my tweezers look pink now.. and they are almost like an HA3 anodizing!

Anyway, here are the new ingredients and a few little notes:

- Woodpal wood restorer made in canada, contains a fairly high amount of phosphoric acid (which coincidentally, can be found at most concrete precast places)
- oxyclean household cleaner... almost the same as hydrogen peroxide
- assorted color match heads (blue, red, and green)
- potassium chloride commonly called lite salt (with or without iodine)
- copper wire strands.

mix ratio:
- 100ml of woodpal or phosphoric acid
- 50ml of dilute oxyclean in water (make a paste)
- 30grm of lite salt
- 45-50 match heads (primary colors can be mixed to produce other colors
- 20-25cm of finely chopped copper strands (use a pair of old scissors)

Mix them all up in a glass container and let them sit for about 10 hrs. Mix occasionally.

Here's what i think is happening (and correct me if i'm wrong all you kitchen labrats outthere ):
- The copper dissolves in the solution to form a mild cupric acid percentage of the phosphoric acid solution. The copper adds the darkness to the tarnish
- The oxyclean acts as a catalyst to speed up the transformation and assimilation of the copper. It also helps dissolve the match heads to release more sulphur. The "oxy" in the oxycelan creates a more corrosive environment for the acting chemicals by providing more fuel for the corrosive action to take place
- The salt contains potassium and chlorides which break down into separate potassium and chlorine elements to provide added corrosion and staining to the metal. remember that bleach contains chlorine!
- The match heads add the color to the mix to lightly affect the final look of the metal

So far i have tried this with one ingredient left out to try to find out which ingredient has what affect on what. The times (after 10 hrs.) for the solution to affect the metal and the resulting affect are:
- 10 minutes - protective lacquer is removed and metal begins to corrode
- 18 minutes - Metal shows signs of frosting. light pitting may show on softer metal like aluminum
- 30 minutes - metal begins to darken and take on light color of match heads
- 40 minutes - metal is significantly darker and shows a darker match color patina
- 60 minutes - metal is darkened in different areas due to undissolved copper laying on bottom of jar. general color is same as about 40 minute mark
- 120 minutes - metal begins to pit and feel much more frosted. cooor remains the same
- 10 hours - metal is slightly pitted to the touch, readily takes oils and dirt from hands. threads will be nominally looser in screws (not enough to affect the performance

These were all washed with clean warm tapwater to remove any further solution and then set aside.

The most important thing is to make sure that the match heads are COMPLETELY dissolved in the soloution before adding any metal. If your metal objects sit on the bottom next to the undissolved match heads, they will impart a stronger color in the area closest to the metal to be affected. If you can get at least 60% of the copper to dissolve in the solution, the affect will be much faster and stronger than with 10%.... when in doubt, let it sit awhile longer (maybe another day) and stir occasionally.

So far, i've got pink anodized looking aluminum rivets and brass rivets with shades of purple, blue, orange, and brown (almost like a mottled damascus) with a much darker color. The tweezers i mentioned earlier have their tips PERMANENTLY stained a reflective polished orange color. they are chrome plated steel. Will leave them in a new solution with different colors to see how it affects them.

Also will try different knife metals to see how they are affected by the solution.

Everything will get a colorful patina now:yikes: pictures to come shortly

 

[rancid badger]

Oh, I am going to have to try that! All those bright yellow buckles I have could do with toning down! The thing is, does the lacquer they are covered
with prevent your magic potion from working?

I used a blow torch on one buckle the other day (in desperation ) that probably removed the lacquer, thinking of it!

None of the buckles I have bought from Leprevo are lacquered and if left in warm damp conditions, for example a bathroom, readily tarnish with no other intervention. It does take a few days for the brass to dull right down.

There again, why not just let nature take it's course and let the metal work dull naturally?

R.B.

 

[Ogri the trog]

I'm a great believer in allowing any tarnish to occur naturally,
especially on knives, but on many other things as well - each stain can add its own part to the story of the piece. The recent recipes are worhty of remembering though, just in case somehting needs to be aged prematurely

ATB

Ogri the trog