DEAR ART NURSE:
I’m a long time reader of the blog and followed with interest the post you did on exterior painted metal art restoration. In fact, it’s connected to the question I have for you:
I am currently heading a group that plans to restore half a dozen Defense Housing Units designed by Buckminster Fuller. These corrugated steel cylinders were once painted white. Now they are in very rough condition and it appears they need to be re-galvanized due to rust and other wear.
Therefore, I was wondering if you have any suggestions for industrial galvanizers. The process has seemed to vary considerably over the last 40 years and I would like to do something that will replicate the original finish.Yours truly, Dymaxion Man
Where do I begin to thank you for bringing these structures to my attention? The idea of painted steel Bucky Fuller buildings is almost more than this modern-architecture-and-painted-metal-loving Art Nurse can absorb.
But enough of my gushing and on to your very important question. In the photos you sent the buildings look repainted. Therefore I’d start by figuring out if that’s true, and if it is, chemically strip the new paint and see what’s underneath. You’ll definitely want to take care of the rust that is bleeding through the surface paint. And you’ll want to figure out whether the pieces were, in fact, galvanized, something the very detailed 1941 MoMA press release you kindly forwarded does not mention. Galvanizing, as you know, is a process by which ferrous metal (steel or iron) is dipped in hot molten zinc to provide corrosion protection. I did some snooping around on the internet and found pictures of other DDUs which showed the telltale silvery-grey color of galvanizing under peeling layers of the original white paint. This is all an educated guess, because determining the materials of a structure through a photograph is kind of like diagnosing a patient via telephone.
But all of this speculation about materials raises another important point: Buckminster Fuller’s works are significant for aesthetic, technical and historical reasons, so it would be best to try not to obliterate their original material while restoring their aesthetic. Re-galvanizing — which would involve sandblasting to bare metal before re-dipping in hot molten zinc — seems heavy-handed. I suggest going easier on the metal: remove the overpaint, see what you have of the original, then figure out your best approach. Without knowing the details, I’d suggest cleaning and removing corrosion with water, local abrasives and solvents, passivating the exposed metal by brushing on a phosphoric acid solution that makes it more resistant to corrosion, and maybe even trying to preserve a few areas of the original paint. At that point you could avail yourself of one of the many extraordinary new industrial paint systems for outdoor metals that would allow you to apply the zinc as a paint layer. This would mean that if someone ever wanted to study the materials that Fuller used, they would be able to do so — because they’d all be right there, under a layer of paint.
There are some fantastic paint systems out there (I have a weak spot for the TNEMEC systems, which incidentally is “Cement” spelled backwards ). But before laying a brush on those Fullers, it would definitely be worthwhile to have an expert look at the structures and suggest the best course of action — or you may end up destroying as much as you preserve. Any conservator who has experience in industrial materials or outdoor painted metals should be able to help you. Of course, only a few of us look as good as I do in a nurse’s uniform…Rx, San Suzie