Clear coat sealer/varnish for cast iron

A. Hi Charnae. I have heard several times that galvanized cages are bad for parrots because they peck at them and ingest excess zinc, but I haven't previously heard about iron being bad for birds in general. Do you have it on good authority that iron is bad for birds? Did a vet tell you, or can you suggest an article you read on the subject?

But as vets often remind us, birds aren't people. So it's probably not likely that anyone knows which paints are and aren't bad for them. So if you want to protect the iron, one clearcoat is probably as good as the next for the birds :-) Luck & Regards,


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

A. I have seen some beautiful work done on parts of a sailboat by a local 'powder coating' company. I'm not real sure of how it's done but I believe it would be worth looking into for your pump. Even though it is called 'powder', the finish comes out a a super tough painted looking finish. - Good Luck!

A. Powder coating, in simplest terms, consists of charging the part with static electricity, and then spraying plastic onto it as a very fine powder. Then the part is baked in a oven whereby the plastic flows into a liquid that covers the part. When it cools, the part has been coated. It is considered an environmentally friendly process because it achieves pretty much the same thing as painting, and in some ways better, without requiring any solvents.

I would expect the powder coating shop to do phosphatizing before the powder coating, which will help to deter rust.

A. You can colour it black. Here is recipe!

20 gm tannic acid
15 gm phosphoric acid
1 lit. H2O

Spray or paint on thoroughly degreased object! Lacquer it if you want !

A. You can paint Cast iron in any color you like.
It is best to paint it with a paint called "Hammerite [affil link]"
since it can be used directly on rusted surface. You only need to brush the loose iron off.

You can also use two colors of lacquer to get an antique look on the surface.

First apply the darker color on all the surface and then spray the lighter color onto a cloth and apply the color with gentle strokes (not to much)

Try using black and gold or Black and Bronze.

Good luck!

A. According to a metal sculpture workshop I took in preservation of metal/bronze items, the best coating is marine varnish with a UV additive. Even with that, the maintenance on the item should be every 6 months for upkeep. There is a book by Ron Young "Contemporary Patinization" that explains the care of outdoor fountains from rust and bird poop.

"You must put a stop to rust..."

A. I was looking for an answer to this and have found on other sites a reference to a product called POR-15 →
I have not tried it yet, but will give it a shot. I just thought I'd share.

It is ridiculously expensive though :-(

Ed. note: Readers, to the extent possible, please suggest generic types of finish: polyurethane, varnish, epoxy, lacquer, wax, preserving oil, single-component or 2K clearcoats, etc., rather than a brand or source ( huh? why?)

A. The full process details would have been more helpful, but try heating the cast iron bathtub at 120 °C for about 30 minutes Effective Metal Temperature. That will drive the moisture out from the porosity inherent in the casting. Allow to cool before you carry out the next step but do no leave it long without the protective coating. All the best.

A. Gurvin has a great idea. Another way is to use multiple steps, similar to the steps you are using now but to add a few additional steps. For example, you may need to use more than one coat and not just go straight to the lacquer, instead use a primer prior to final top coat. You may find it's best to use a color that mimics the original coloring or go with something more common like black.

A. Hi Barbara. I'm surprised that it's made out of cast iron rather than brass or bronze. Have you tested it with a magnet? But I think the thinner single-component coatings like Everbrite [a finishing.com supporting advertiser] are probably better towards not distorting the peal of a bell than heavier two-component coatings. If it actually is brass or bronze you might also consider brass lacquer [affil link] because this is periodically redone fairly easily.

Regards,

A. Hi Bjean. Unfortunately I think your plan to maintain that lovely statue may not work. Clearcoats are not shrink wrap; they will not stop the rust or the paint from flaking. Applying them on top of flaking paint and loose rust will likely only result in the clearcoat and paint coming off together.

But try a thin penetrating clearcoat like Everbrite [a finishing.com supporting advertiser] and hope for the best; they have a page about protecting rust finishes Eventually you may want to have the statue abrasive blasted and phosphated before painting.

Regards,

A. Hi Harry. That's as much a question of taste as performance. Easiest and most durable would be black stove paint; it's made for the job. But covering up your polishing work with black paint may not satisfy you. You can also just do a clearcoat, assuming the atmosphere is not excessively corrosive. A middle of the road solution, and the one I'd prefer is stove polish; it is gray and matte, but does let some of the character show through.

You mentioned the weight of this fireback, which may limit how you can handle it, but ideally it should be spaced out a little bit from the wall rather than being bolted tight to it, and with an air gap on the bottom, because the way such devices best help provide fire protection is by being having air cool the radiant heat they absorb, and they're able to do a better job with air flowing on both sides of it, rather than conducting heat directly to the wall.

Regards,

A. Hi Pat. As vets occasionally remind us, birds aren't people, so I can't be totally sure ... but I don't think common clearcoats are toxic to people or birds.

Luck & Regards,