How to make rust

Oct 07, 2005 18 Replies

A friend wants me to fix a "sculpture" thet he has where a weld cracked. Looks like some sort of scale or something that is part of a larger piece. I suspect it was MIG welded with a cold weld as what he describes should not have caused it to break. Anyway I plan on TIG welding it. Part of the uniqueness of the part is it is completely covered in rust. Obviously, I have to clean this up to weld it. After I am done, how can I promote rust to take it back to its original appearance. I will clean as little as possible. I'm sure ther must be some way other than dampness and time. Any advice?



Thanks in advance. Barry


If you live in Florida, Louisiana or Texas near the coast, just leave it out overnight.

Steve ;-)

Some water with a salt in it. Table salt will work fine. A little heat, but not so much as to evaporate the water.

Dan

ammonium nitrate and some dampness works fantastically.

i

Get a bottle of ferric chloride etchant for PC boards from Radio Shack. Pour some in a plastic or glass tray or dish, leave it near the work. It'll rust overnight.

Don't do this within 20 feet of any machine tools you care about. DAMHIKT.

Piss on it. Literally Weld with mild steel wire, soak a rag in urine and lay the rag over the weldment.

Or you could use ferric cloride "Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the s*it out of you for torturing the cat." Gunner

Gunshops sell a product called "browning" - used a little like "bluing", but for older muzzleloader kits. I believe it's nitric acid. Warm up the part a little bit, dab a bit on there and "instant rust". Ken.

Leave an open bottle of Hydrochloric Acid near the piece. It will rust everything in the shop within two days. Bugs

An extension of Gunner's suggestion is my favorite. Start with an appropriately sized keg of beer and a few friends. As the afternoon progresses, make use of the sculpture. You may get faster results covering it with plastic in the mean time.

Steve

Pee on it once a day until the desired finish is achieved. Or buy the brownells browning product that does the same thing.

Be aware that there are two types of browning. One leaves a smooth surface, the other leaves the antique, original type of controlled rust. The latter is what you want.

If it's NOT "controlled rust" you want, but just an even layer of what you'd see when clean steel is left out in the elements, then, that's pretty easy.

First, you should clean the work back to "pretty clean" -- light hand wire-brushing, or maybe very fine grit blasting.

Aquire a small bit -- just a couple of ounces of potassium nitrate. "Stump remover" from your local home center is usually about 95% KNO3. Dissolve about two ounces in a quart of warm water, and add a few drops of dishwashing detergent to make the water wetter.

Wipe down the whole surface with the solution, making sure to evenly wet everything. Let it drip-dry, and leave it in a humid (but otherwise dry) environment for day or two. The process has started. You can cloth-wipe off the excess loose rust before you return the product, but it will keep on actively rusting for about two weeks from each application of nitrate.

LLoyd

Roy said the same thing I was going to say. I couldn't keep my tools from rusting when I had Muratic in the shop. Perphaps put a big plastic bag over the work with bucket of Muratic at the bottom.

(Please note: Muratic is REAL acid. Wear eye protection!!!

Send it to Alabama or most any place on the gulf coast...It will be covered in rust within a few days..........I cast a heap of bronze and brass sundials last year or maybe it was the year before, but one thing the purchaser asked was to have them with patina if possible as they would bring more money for him and he had no way of doing or knew how to do it. I took a bag of fertilizer a bit of water mixed it up put em all up under a plastic sheeting tent afair with rags and open containers of the fertilizer mix. I even sprinkled pellets of fertilizer here and there on them. In no time they were a beautiful blue green shade of patina, and just a hit here and there to shine a spot or two had them looking great. I had considered taking aleak on them daily or more as the need arose.........Heck, it cost me $5.50 for a bag of fertilizer i used pond water and got an extra $4.00 for the patina on each one......Cast a total of 60 sundials that time.......

============================================== Put some color in your cheeks...garden naked! "The original frugal ponder" ~~~~ } ~~~~~~ } ~~~~~~~ }

Got any copperas (ferrous sulfate)? Or a compound salt like ferric ammonium sulfate. Both will work similar to the ferric chloride suggestion.

I find HCl fumes tend to give a thin, even layer of rust. To really grow pits and mountains of glistening reds and browns, you need something more dramatic. A combination of these corrosive salts or fumes and some caked-on salt and ample moisture would do well.

Tim

Since it isn't small it might be easier. Get a pot of hot water. Tap hot is just fine. Add salt and then stir it in add more... A strong salt (pretend The Great Salt Lake) ( Ocean) - and then soak a junk towel. Tie the towel over the clean metal. - Maybe more than one. (Shop rag material is just fine). Salt water is what you want.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

Barry wrote:

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