Rust finish for galvanized tin?

A. Hi AK. Muriatic acid is quite strong; diluting it 50/50 will still leave it quite strong. A sprayer will work, but make it a plastic one; muriatic acid destroys brass quickly. No one even knows what ingredients are in these less aggressive substitute acids; I assume they work but can't guarantee it. If you use muriatic acid, it should cause rust itself. But after rinsing well you could spray with bleach ⇦ bleach/sodium hypochlorite in bulk on eBay or Amazon [affil links] , which rusts bare steel well.

Luck & Regards,

A. Hi, Brian. Please excuse my pedantry, but there is no such thing as "galvanized tin". Galvanized means coated with zinc by dipping into molten zinc, and tin is an element whose melting point is much lower than the melting point of zinc -- so tin articles would melt if you attempted to dip them into molten zinc.

But people sometimes use slang and call steel sheet metal "tin" -- I'm quite sure that's what you mean in this case, right?

Zinc can't rust (although it can corrode into a white gummy or powdery corrosion product). So, no, you can't 'rust' galvanized steel sheet metal while it still has the zinc coating on it. But you can remove the zinc coating with muriatic acid ⇦this on eBay or Amazon [affil links] , and then the underlying bare steel sheet metal will quickly rust. Remember that muriatic acid is a hazardous material requiring good ventilation (outdoors), the wearing of full personnel protective gear, including rubber glovesrubber gloves ⇦this on eBay or Amazon [affil links] and goggles ⇦this on eBay or Amazon [affil links] , and careful handling and knowledgable disposal. Good luck!

A. Hello Dixie. Again, tin can't rust; only iron and steel can rust. But once again you probably actually mean "steel sheet metal" rather than tin? If so, repeated spritzing with vinegar and salt while leaving it in the sun should quickly rust it if it's not galvanized. Good luck!

A. Hi, Kay. Hopefully they'll get back to us, but as I said, you won't get galvanized steel (like chicken wire) to rust as long as it still has the galvanizing on it because the galvanizing is applied for the specific purpose of keeping it from rusting :-)

Galvanizing is pretty effective at deterring rust, and vinegar and salt might not rust it in a reasonable period of time. I think you might want to strip the zinc off with muriatic acid to rust the underlying steel. Good luck, but be very careful if you use muriatic acid.

Q. Ted, Thanks for answering so promptly in regards to galvanized tin.

What I want to do is get a rust covering on objects like tin cookie cutters, small bells with clappers, and jungle bells. I have a small [mini] watering can that says on bottom "Galvanized Tin- Made in India, not guaranteed for leaks" I have also seen flat tin ornaments like stars, sleds and etc. that are covered with rust. They must have been dipped in some type of acid to remove the galvanized covering. This is what I'm looking for. Something to remove the covering and a method to create the rust. Thanks for any information.

Kay R [returning]
- Pt. Pleasant, West Virginia

A. Hi, Kay. I'm confident that --
1. cookie cutters are made made of steel that has been electroplated with tin (because tin plating is "food safe" whereas zinc galvanizing is not).
2. jingle bells would be steel that was nickel plated (or maybe silver plated);
3. the watering can is made of steel sheet metal that has a hot dip galvanized zinc coating (like the chicken wire) despite its erroneous label.

Zinc, silver, and tin are all non-magnetic -- does a magnet stick to all of the items, indicating that underneath the coatings they are steel and can therefore be rusted?

An issue that probably isn't fully clear to you is that steel, tin, zinc, silver, and nickel are all very different materials from each other -- not even mentioning that some of the items may have a clear coat paint on them. I apologize that it's quite confusing but, although they make look similar, different metals react very differently to the same chemicals. If a friend asked you how much of "this white powder stuff" they should use to bake a cake, you would have to tell them that until they could identify whether the powder was flour, baking powder, or arsenic, you really can't answer. And I'm unfortunately in a similar position :-)

Although zinc can be removed with muriatic acid, a different procedure is required to strip tin (probably lye would work), but you would find it difficult to chemically remove nickel or silver with anything available to a hobbyist. Maybe you can use sandpaper to sand the plating off some of the stuff instead of trying to figure out what acid will do it? Once you are down to the steel base, they will rust with vinegar and salt or any other rusting process you read about.

One final option, and maybe simplest is to simply paint/patina with a rust solution;.
... since the rust is already in the patina solution, it should work on anything. Good luck.

Good luck!

A. I've built a beautiful "rustic" bedroom with corrugated sheet metal for the inside ceiling. I was able to get a "rust" paint from a local hardware store. You paint a thin layer of paint and it oxidizes the metal. It may create the look that you are trying to achieve. It worked for me.

A. I have found a product at the craft store called instant rust [affil links] ; it's a rust antiquing solution. It works great.

A. Hey, why don't you simply try rubbing it with coarse sandpaper? If you are successful in getting the finish off, you could get the part wet with salt water and let it sit around.

A. I just came across this question while searching thru Google about rusting metals. I did find one lady rusts her metals with a solution of 1 cup of bleach to 1 cup of vinegar. This is very fumey, do it outside. Stay away from the fumes. This is supposed to work fast. How fast I don't know......yet! :O)

!! Cheryl, the bleach bottle has a warning not to mix it with other chemicals! Bleach is simply chlorine gas dissolved in water that is so alkaline that most of the chlorine will stay there. Neutralize the alkalinity with an acid like vinegar, and the poisonous chlorine gas comes roaring out. Many people have died from this. If you insist on doing it anyway, yes, only do it outside ... and stay upwind! Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi, Vicki. Maybe your ceiling tile is painted a metallic color rather than being galvanized? Although I am not sure exactly what the problem or misunderstanding is, rest assured that muriatic acid violently removes galvanized zinc coating almost instantly. Remember that muriatic acid is very dangerous though.

A. Muriatic acid will strip all zinc from your tin. If you are having problems try rubbing the surface with a scotch brite pad. Some of today's zinc alternatives are acrylume, zincalume and galvalume; these don't react as well as straight galvanized but with a little roughing up they strip very fast.

Be very careful, though, the gas produced from the reaction of the zinc and the muriatic acid is hydrogen cyanide, they use it in the gas chamber and it is listed as a chemical warfare agent. 300 parts per million will kill you in mins. Use chemical respirators and protective clothing and eye protection.

We rust roughly 1000 sq. ft. of galvanized a year everything from welded wire to seamless gutters.. hope this helps

---

! I certainly agree with your precautions regarding protective equipment when you strip zinc with hydrochloric acid, Brian! Thanks. Yes, it evolves poisonous chlorine-based gas, not too different from some WW1 chemical warfare gases. But a minor point regarding the science, I don't think it can actually evolve hydrogen cyanide. Hydrogen cyanide is H⁺CN^- and I don't think you can possibly create CN from muriatic acid (HCl) and zinc (Zn).

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007

A. Hi Chris.

Are they brand new or recycled stuff from a retro architecture store? Painted or galvanized? Thanks.

Regards,

Q. The panels I purchased are brand new "tin coated steel". Trying to get them to oxidize but not rust. Just looking for a dulled finish

A. Hi. I'd try vinegar on a sample Chris. If that doesn't work, oven cleaner ⇦this on eBay or Amazon [affil links] . It would surprise me if they are really "tin coated steel". Good luck.

Regards,

A. I am positive that the roof is not tin. First test it with a magnet to make sure the underlying metal is steel, Doug, because only steel (and iron) can rust. Then sand off the coating; then try the bleach OR vinegar & salt.

A. Hi Nancy Jo. After dozens of postings explaining that tin is not galvanized sheet steel, which is not plain steel sheet metal ... and that it's difficult to offer answers because they all react so differently, I now don't know whether you are absolutely insisting that you have real tin or you're just persisting in calling steel sheet "tin" anyway :-)

All metals except gold and the other precious metals eventually corrode away. That's why gold can be found in nature but other metals must be smelted from ore. I think solid tin metal would be okay outside for a while, but sorry, I can't think of any typical applications to refer you to, as I've never seen it used in contact with soil.

Sheet metal will of course eventually corrode away, but galvanizing it with zinc will prolong its life, and you will not get the brown powdery iron oxide corrosion product that we call "rust" on it until the zinc coating has worn/dissolved away. Good luck.

Hi, Joe.

A steel warehouse like Ryerson will have steel sheet in all thicknesses and widths without galvanizing. I would dilute the acid as much as possible because it's dangerous to work with. Wear goggles ⇦this on eBay or Amazon [affil links] and rubber gloves ⇦this on eBay or Amazon [affil links] . Cut some short sample pieces and spritz them with varying strengths until you have a process down. As consumers we are almost never given enough data by the manufacturer to be able to work from theory instead of trial-and-error. Good luck.

Regards,

A. Hi. Everbrite [a finishing.com supporting advertiser] offers a simple one-part clear coat. Apply to a small area to make sure it suits you as "will not change the appearance" is a tall order and it's very hard to promise that you can coat anything with anything without affecting the sheen in some way. Good luck.

Regards,

A. Hi D. The first thing to keep in mind is that while anyone can paint a wall, few can paint a Mona Lisa. When something catches our eye, it's often because it's rare & unusual because it's difficult. We don't know your artistic level vs. the contractor who did the house in Newport Beach.

The second question is what are your gutters made of: aluminum, copper, or galvanized steel? Are the Newport gutters made of the same material?

There are "rust finishes" which are like metallic paints (actually patinating solutions) with rust in them, and these are surely your best bet if you are not simultaneously an artist and a metallurgist :-)

Your "sunsurf or something like that" may be one brand or seller, but there are many, such as the Triangle Coatings "Instant Rust" illustrated above. Good luck, but try a small spot because, as I said, if it's "eye-catching"" it's probably because you see it so rarely; and if you don't see it often, it's probably because it's hard to do well :-)

Luck & Regards,

A. Hi Allen. You're not going to be able to leave loose fluffy rust on the surface because, although the clearcoat may stick to the rust, they'll just come lose together. You need to brush it so only the adherent rust remains before clearcoating. Then a "wet" clearcoat, maybe Everbrite [a finishing.com supporting advertiser], should work. Good luck.

Regards,

A. Hi Nick. The galvanized coating is zinc, which reacts very actively with hydrochloric acid. Once the zinc is gone and the acid is trying to react with the underlying steel, it's going to be a much gentler reaction.

Regards,

A. Look up Amy Howard paints. She has a cleaning solution called clean slate and then use her oxidizing solution to get the aged look. Worth looking up ... lots and lots of how to videos! [affil link]