Where can I purchase terne plate and long terne?

A. Hi folks. Finding "Terne" and "Long Terne" is no problem at all. The Thomas' catalog and many other directories list a hundred suppliers.

The actual problem is that the words have lost their meaning -- which makes it hard to know what you want, difficult to specify it, and aggravating to try to get it :-)

Way back when (from colonial times to the 1940s), "terne" and "long terne" had a very specific meaning, i.e., a hot dipped coating of 80 to 85% lead, with the remainder tin, as a roofing material that would last a hundred years and more. But in reaction to the toxicity of lead, alternative coatings of tin plus zinc plus small amounts of other metals started to be adopted and called "Terne Alternative", "Terne 2", "Terne Replacement Coating", etc. Unfortunately this happened so long ago that shorthand & slang crept in over the years ... and, instead of calling the "Terne Replacement" by its proper name, it became part of the lexicon to simply call the replacement "Terne". So today Terne doesn't necessarily mean lead-tin, nor does it necessarily mean tin-zinc ... it ends up meaning nothing at all. Both the tin-zinc and lead-tin are available though.

If you need the lead for chemical resistance or lubricity, you'll need to contact the suppliers who SAY they offer "Terne" and give an actual specification for the lead content and make sure that's what they give you. Most roofing suppliers will claim they have "Terne", and many really believe it, when they haven't actually stocked real Terne for decades :-)

Be careful! Tin-zinc alternative coatings may be satisfactory for a roof, but installing tin-zinc in a chemical environment, when you thought you were installing lead-tin could be a disaster.

Regards,

A. I worked in roofing/sheet metal fabrication from 1977 to 1984. The material I worked with came from Follansbee Forge. They specifically stated on their label that the material was surfaced in a lead/tin mix. That same product was still in common use during my last contact with the industry in 1994.