Galvanized Wire and Zinc

Many bird owners have wondered about building their own cage at one time or another. I’m writing this to share the knowledge I’ve gained about zinc and the process of galvanizing.

Galvanized means iron (steel) coated with zinc. If it is coated with something else then it is anodized or plated. Galvanized implies zinc. The two most common methods of galvanizing are electroplate and hot dipped. Sheet metal is usually electroplate. This is a thin shiny finish with a criss cross, crystal looking pattern, like frost on a window. Wire is usually hot dipped, it’s a thicker coating and dull in appearance.

What is cheap and easy to find at the hardware store or home improvement store, is that screen looking stuff that comes in various sizes. It is called hardware cloth, and it is a grucky hot dip. Look at it closely and you will see lots of “extra” particles and little globs of *solid zinc* stuck to it. It works fine for rabbits and chickens. Rabbits and chickens don’t climb all over their cages with their beak. A sharp little conure beak can break off one of those little globs, and they are small enough to be swallowed.

So how dangerous is zinc. Well, here in the northwest where it rains a lot in some places, it is possible to have an entire roof covered with moss. So a simple trick is to take a strip of sheet metal, only a few inches wide, and tack it onto the top of the roof. The teeny tiny amount of zinc that washes off when it rains, kills everything on the roof.

Also I might mention, when I was learning how to work with metal, the shop was well equipped with lots of machinery and tools and welders. There were many ways a person could be injured and we routinely inhaled nasty fumes from the welders. Out of the entire shop, my macho teacher with over 15 years teaching experience, really only went out of his way to warn us of one thing…….. zinc! We were told to never get a torch anywhere near a piece of galvanized, even with the exhaust fan running!

Now having said that, anyone who is planning to build some breeder cages or an aviary will probably still be considering using some type of galvanized wire, because that tends to be what is available to work with. Hardware cloth should never be used. It is too easy for a bird to break off one of those little leftover globs that are still stuck to the wire. Many breeders use what is called galvanized `after’ weld wire. This is a heavier wire and doesn’t have the “globs” stuck to it.

There is still a problem with the after weld wire though, and that is rust. (Of course zinc rusts, it just keeps the iron underneath from oxidizing.) And any wire exposed to the outdoors will rust faster than an indoor cage. As it oxidizes it will look duller and duller and eventually will start to turn whitish in color. You can touch a piece of galvanized metal that has been left outside, and have the oxidation come off on your finger in one pass. If it comes off on your finger that easily, a bird can lick it off while climbing on the cage. Breeders scrub their cages with vinegar and water a couple times a year. The scrubbing washes off some of the old rust and the vinegar somehow retards new rust, but can’t stop it completely. And of course the vinegar wash won’t last long if the cage is left outside.

I have heard of people sending their galvanized cages to a shop that does a powder coating type of paint job. I don’t know how well that works, zinc tends to be a poor paint primer. There is also such a thing as paintable zinc, but I have only seen it on sheetmetal and I don’t know what was done to it to make it “paintable”. The best situation would be to take the raw iron wire in to be nickel plated, and forget about zinc and paint altogether.

Generally speaking, the safest metals are what you find in your kitchen. Stainless steel is a hard alloy (with nickel) and is the best. Iron is OK, it just makes a mess when it rusts. And aluminum is OK, except with tomatos and acidic foods. You may also have copper cookware. But the copper metal is on the outside, for heat conduction and appearance, not on the inside. However, copper is relatively safe since most homes have copper pipe for drinking water. Something like a copper bell should be safe for a bird. But if you have ever seen those ornamental copper cages with the heavy green patina (chemically induced), those are meant for mechanical birds, not real ones.

A mild case of metal poisoning can “depress” the nervous system. Wouldn’t that make you feel irritable? uncomfortable? unhappy, harder to think or sleep? all of the above? Is that how you want one of your best friends to feel? And a serious case can cause death. It is my opinion that zinc is as bad as lead and mercury.