On 14/03/2019 14:42, Chris Hogg wrote:
On Thu, 14 Mar 2019 13:09:31 -0000, Mike
wrote:


I need to repair loose fittings on the outside of my wife's pottery
kiln. An outer skin of stainless steel encloses very soft bricks that
can withstand 1300 degrees C. The outside gets too hot to touch; it
melts mains cable insulation. I need to replace loose screws that go
through the very thin SS into the bricks. I propose stainless steel self
tappers. Plastic rawlplugs won't do. Can you recommend a plug material:
how does Araldite behave at high temperature? Another resin? Polyfilla?

There's often a layer of fibre insulation between the bricks and the
SS skin, but I agree, the skin does get very hot.

I would suggest not plugging the bricks at all if you can help it.
They are usually _very_ soft, and won't take any sort of stress such
as may be created by some sort of plug. For example, you can usually
push a nail into them by finger pressure alone. They're designed to
insulate, not to support stress. But if you really have to, then these
self drilling metal plasterboard plugs might be OK. Just make sure you
don't penetrate the bricks right through and make contact with the
Kanthal wire elements. That way leads to a shocking and possibly fatal
experience. https://tinyurl.com/y6dkulh6

But I'm not clear as to quite what you want to repair. Is the SS outer
skin becoming loose from the brickwork kiln lining, or is it an
external fitting (such as a hinge or closing clip) that's come lose
from the SS skin. If the latter, you could try pop riveting the
fitting to the SS skin.

You've reflected a lot of my thoughts here. The stainless steel skin
contains the bricks and if things have become loose, a gigantic jubilee
style clip would be a far better solution.

The bricks are very fragile, any force from a plug will crack a brick.
Keep the bricks in pure compression instead.