Patina Formulas for Iron and Steel

A. Hi Janielle. I am not an artist, but once the paint is dry, sanding it off in some spots is probably one answer, and possibly following by painting those areas with an instant rust [affil links] formulas. Or you could probably mix iron filings [affil links] into a clear coat like Everbrite [affil links], so it will start rusting.

Luck & Regards,

A. You could take a look at this page: www.finishing.com/faqs/patina.shtml. Or you could contact Sculpt Nouveau [Escondido, CA]. Hope this can help.
Sincerely,

A. Hi Fulvio. The "Blackening and Antiquing" chapter of the Metal Finishing Guidebook is at least a start, although brief.

Iron and steel can be blackened, but if you want a colorful finish such as the verdigris of copper, the way it must be done is by starting with copper plating, or 'painting' on a 'wash' which contains the necessary copper or other metal (this is essentially how the store-bought patina solutions for iron and steel work -- putting copper salts onto the iron or steel.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Enpeekay. I believe you are correctly noting that while the corrosion products of some metals like copper can be colorful & decorative, the corrosion product of iron and steel is just rust. While this is true, and iron will not corrode colorfully, it is possible to apply "washes" of copper or other metals to the cast iron. These are sold as 'patina finishes' by suppliers such as Modern Options / Sophisticated Finishes [affil links] .

Luck & Regards,


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

A. Dear Sir,

I've been looking into the patina finishes as well...I've been seeing a lot of it done on HGTV..... Yesterday I was in JoAnn Fabrics and noticed that they carry a line of products that will give you the patina finish your customers are requesting.

Several colors too... Hope I've helped.....

A. Dear friend:

Over my years of experience in the field of industrial coating, I had come across various finishing on almost every surface including glass, tile, besides wood, metal etc. patina finish had always been one of my favorite finishes and it can be obtained on any surface including metal. In order to do patina finish, one must correctly choose the item to be patina finished. Not all items can look good in patina finish like an automobile or a simple chair. The product should have a minimum of some sculpted look like intricate turns and twists in design or a bust of a person. Basically, the product to be patina finished should represent a metal like a window grill but not a walking stick since a walking stick is never made of a metal.

Now, how to do a patina finish on a wrought iron furniture: first, clean the metal thoroughly with phosphoric acid to remove rust, dirt completely, This process will de-color the metal giving it a neat look. Next, dry the metal surface and use some mild solvent to remove the excess residue of the acid. apply epoxy primer preferably using spray method. then sand and spray paint first coat in brilliant white paint. then take some dark green stain in concentration and spray lightly on the dried white painted surface. Take a clean cotton waste dip it in mild solvent and squeeze the excess solvent back in container and then slowly dab on the surface. you will find some brilliant formation on the surface when the stain starts dissolving with the solvent and spreading itself out on the white background. Finally, finish with a matte lacquer mixed with green tint. use a little bit of white smoky spray on the dabbed surface before you use the final lacquer. continue spray the lacquer to achieve the desired tone. this is just one of the dozen different types of patina finishes. rest you can try and learn on your own. good luck.

A. What kind of finish? The natural patina of iron is rust, bronze goes light blue, if you use chemicals you can get a wide variety of colors. So what do you want?

Patina is a film on the surface of bronze or similar metals (produced by oxidation over a long period or by a chemical process); a sheen on wooden furniture produced by age, wear, and polishing; or any such acquired change of a surface through age and exposure. On metal, patina is a coating of various chemical compounds such as oxides or carbonates formed on the surface during exposure to the elements (weathering). Patina also refers to accumulated changes in surface texture and colour that result from normal use of an object such as a coin or a piece of furniture over time.

A. Hi Loyd. A point which I think earlier posters were referring to is that, unlike copper alloys, cast iron and other ferrous metals don't form colorful patinas by themselves. They get rusty or blackish and that's about it :-)

To get a blue & orange coloration on cast iron you need to first electroplate it with copper, or at least apply a copper-based wash which you can subsequently oxidize. You can e-mail your photoshopped pic to mooney@finishing.com for posting here.

Regards,

A. Hi. For one example, please look at Modern Masters on Amazon.
You apply their primer, then this water-based "paint" with copper particles that are designed to react, then another solution that will turns the copper green or whatever. There are other vendors.

As a slight alternative, I believe that Jax offers a copper plating solution, perhaps copper sulphate [on eBay or Amazon]based, which deposits copper onto clean ferrous metal without heat or electricity. I have no experience with either of these approaches and am not vouching for one over the other ... I'm just saying that you have to get a copper layer on the cast iron if you want to eventually get a blue-green or orange color because the oxidation products of ferrous metals are not those colors. Good luck.

Regards,