I guess you didn't read the links to the manufacturer sites upthread a few
The NEC standard does not require EMT to be protected at all but I have never
seen any that wasn't. Back in the 20s it was painted but anything since WWII is
galvanized, either electroplated or hot dipped.
When I was a state electrical inspector I saw stuff in government buildings
that went back that far.
I only checked one manufacturer (I found a listing of
65 of them on some website), but Allied
clearly states that their product is galvanized.
Ah, the marvels of the web and search engines ...
Could be you and I have egg on our faces. I am almost certain I have seen
stickers on some EMT that says it is aluminized, but I'll be damned if I can
find anything that indicates I'm right when I do a search on the web.
Maybe my next trip to an electrical supply warehouse will bear fruit.
There has been aluminum EMT.
It is rather famous for destruction of concrete buildings where it has been
I cannot recall if the best book on the subject is "Design and Construction
"Construction Failure" or "Why Buildings Fall Down", or one of the similar
one of them has a good piece on it.
There are several types of metal conduit - the most common being EMT
(zinc electoplated steel in most cases, cold galvanized in others) ,
Rigid conduit (heavy walled steel conduit) and aluminum
conduit(similar to rigid but "soft" aluminum)
EMT, or Electro Metalic Tubing is connected with clamps and sleaves -
it is too thin to thread.
Rigid and aluminum comduits are generally threaded.
On Mon, 12 Jul 2004 21:07:19 -0400, "Shawn" <shawn_75ATcomcastDOTnet> wrote:
It sets up a galvanic couple with iron rebar, with the result that the
rebar is rapidly corroded away, weakening the concrete structure.
Concrete is alkaline, and it never really completely dries, so it acts
as the electrolyte of the corrosion cell.
Yep. Still remember the windows in our former embassy in Cuba, where steel
screws had been used to attach aluminum. The more electronegative was eaten
up to an inch clear away, leaving the screws to finally rust in the salt air
while we were away.
That's why they galvanize instead of use lead paint under your car.
I'm going to bet, however, that the interior of the conduit has enough room
for the developed aluminum oxide.
And it still rusts when in contact with wet concrete floors. Or wet
"The entire population of Great Britain has been declared insane by
their government. It is believed that should any one of them come in
possession of a firearm, he will immediately start to foam at the
mouth and begin kiling children at the nearest school. The proof of
their insanity is that they actually believe this."
-- someone in misc.survivalism
Yup..you get that nasty yellow mang that grows on it...
That rifle hanging on the wall of the working-class flat or labourer's
cottage is the symbol of democracy. It is our job to see that it stays
- George Orwell
It's galvanized, just with a thin coating. Usually electroplatd on
rather than hot dipped.
Somewhere I have seen a chart that graphs the coating thickness in mils
versus the life expectancy in years for normal and salt air exposure.
Harold & Susan Vordos wrote:
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.