ECN Electrical Forum
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mbhydro, that link is frightening! Especially the effects on electrical wiring in the sublink.

This looks like a big story unfolding, Greg, and could get worse than the asbestos or aluminum conductors sagas.

One aspect of this mess that I have trouble getting a grip on....

Thinking about the bulk, weight, and ease of damage from shipping and handling, how 'cheap' (or economical) can sheetrock from China be??

It is funny you ask that question because I asked that same question myself. I was told that a standard shipping container costs the same to ship from China whether it is full of drywall or cotton balls. They apparently charge by container, not by weight.

I actually asked this question because of the influx of Chinese-made batteries that I've been seeing. Those things are pure dead weight, so I couldn't help but wonder how much cost savings there can be after shipping them halfway around the world.

I have read that it costs more in North America to ship the container from the port to the end user by rail and truck than it does to get it here by boat.

With the proper dunnage in the container to control movement there should be little to no damage to the contents under normal conditions.

Getting back to the drywall the HVAC site had pictures of the damage to AC condensers and electrical controls from the fumes outgassing from the drywall. Everything copper was green and black. I'll see if I can find the topic on that site and post a link to it.

he issue at the time was not cost, it was availability. Drywall was scarce and houses were sitting idle waiting for drywall. My wife says the computed cost of a house sitting idle was something like $350-400 a day to a production builder.
We now understand it might have actually been a lot more than that if the bubble pops before you close

Everything I saw was black. The scale on the wire was very easy to get off. It flaked off with your fingernail leaving fairly shiny looking wire behind. If you see green on the wire I would suspect that was water damage.

As an aside, to advance the theory that this may have been water damage to the drywall on the ship, the drywall I saw that was removed did have traces of black mold on the back and that might explain some of the respiratory problems some claim.

If the gas coming off is sulfur trioxide, it will form sulfuric acid just by absorbing moisture from the drywall itself, as gypsum, even if apparently bone dry, always contains water in its crystals. This would probably make the sheetrock crumble as it destroys the gypsum crystals. If its sulfur dioxide gas, that can convert to the trioxide in the presence of air and a catalyst, such as metals, salts, oxides, organic materials or sunlight. Both gasses are toxic. Once the acid is formed, it will strongly absorb water from any source and hold onto it tenaciously. IMHO this acid will not be removed from a house just by ventilation, for in a damp climate that could just make matters worse. In fact, H2SO4 corrodes some metals better when dilute. The good news is that it is killed by copper and cement, so once all the wiring, concrete and plumbing have vanished.....

Whatever it is, it only seems to affect copper. The aluminum hub on that garage door opener was pristine and the zinc over steel screws are still shiny. The brass keys were hanging on the wall 8 feet away and they were black.