High Temp Expansion Joints

[Breech]

Are these joints only in the coating or are they actually into the refractory material?

Was there an issues that brought this about?

[Sanny]

I believe that the body of the beast is two layers. PLUS a skim coat inside, to make it white. The expansion joints, if I understand correctly, are in the inner layer (under the white skim coat).

I don't believe there was a problem, but rather than have the pressure of expansion on the outside, where the cosmetics are (tiles or texture), the expansion joints will allow movement. The combination of two layers, plus joints, will minimize the stress on the exterior.

Or maybe that's not it. But that's what I believe, and I think it's a good story.

[DennisLinkletter]

Re: High Temp Expansion Joints

Are these joints only in the coating or are they actually into the refractory material?

Was there an issues that brought this about?

There were two areas that always got hairline fractures. When discussing this with the guys at Harbinson Walker, I was told if it can not flex/expand uniformly it will open into these hairline cracks. They also told me not to worry about the cracks as they close when the cooker cools and the materials returns to it's cool size. They said it's normal and acceptable.

I told them that I wanted to control where the movement was as the cracks could cause customers to worry their cooker is going to fall apart.

They said that expansion joints were the only way to prevent these as all material expands when heated.

We make cuts 3/8" cuts into the dense refractory material inside in the corners where the hairlines usually were. After the cuts the hairlines never appeared.

[Sanny]

See? My response was totally fictional. But I like it anyway.

Of course, I like Dennis' response more.