Does anyone know what sort of temperatures bull wire will take before it starts to stretch and melt? By bull wire I mean specifically the wire used to hold up suspended ceilings as you would have in office buildings and the like.
Flobbers... I guess you're thinking of something like 2mm hot-dipped galvanised wire.
A suspended ceiling has to incorporate a certain amount of fire protection for the suspension system. I guess it would fail long after a building would become dangerous and uninhabitable.
Builder, I'm thinking of using it on a kiln as a bit of a patch up job. The kiln fires to around 1200 degrees Celsius and maintains that for a while so I need a wire that will stand up to it.
As long as it isn't on the inside of the kiln but on the outside used as a tensile component to hold together then it won't get to anywhere near it's melting point.
The galvanising will burn of almost immediately and ordinary steel would oxidise fairly quickly. A heat resistant grade of stainless might last a while but even then it might be pushing it depending on how hot it gets. Something refractory under compression might be the best way to go if possible. Can you give more details?
There is a heat resistant wire called 'kanthal' usable up to 1400C. It is for sale on Ebay. Tungsten MP 3000C is commonly used as fishing leaders but I don't know if it is available in a suitable thickness.