ENC...
I am a bit puzzled and curious by the description of "rare" A36 steel. If this is a piece of the WTC, OKC Murrow Federal bldg (sp?), Edmund Fiztgerald, Titanic, etc... then the MOUNT design [fixed or floating]... and physical security... may be as significant issues as corrosion protection.
IF NO coatings are allowed, then I doubt if A36 steel would survive long without rusting.
Suggest You discuss possibility of using a thin coating of Corrosion Protective Compounds [CPC] in a continuous maintenance scenario. This coating will produce a slightly glossy appearance, but is none-the-less "temporary" and esily removed. The coating would require maintenance on a frequent-periodic basis as follows: remove the "object" from its mount; solvent clean it to remove the old CPC, grime, dust, "bird-shit", etc; re-apply a new thin/wet CPC film-coating and allow to "dry"; restore object to it's mount. Avoid handling with anything but clean cotton cheesecloth or gloves. The object could last for years like this with minimal rust.
As previously suggested, I think that if the mount [or a hidden attachment to the mount] is anodic to the "object", that would be "good" also [especially if it is easily replaced].
An other idea is to allow [or chemically force] the surface to develop a protective rust patina to form. If this rust remains undisturbed by handling or other factors, it could outlast us all! Caution: This may/may-not be advisable in a highly poluted/wet [seacoast] atmosphere... but in a dryer/cleaner climate may work very well.
Another Idea would be to carefully apply a thick copper-plating to the object... and allow a beautiful copper-green patina to form [under similar circumstances as mentioned in previous paragraph]. Curators may not "like" this idea... but the Statue of Liberty is a great example of copper-patina protection... even in a seacoat environment! Regards, Wil Taylor
