Thermal conductivity of two welded plates? Answered
I am in the process of building a wood stove (details on FE Blog) mainly from scrap metal, but I have got it into my head that a stainless steel hotplate would be nice. I wanted one 10mm thick, round with a diameter of 390mm. As it turns out 6mm seems to be a bit of a threshold for stainless, and anything over has to be laser cut or similar and is loads more expensive. Like £80 is the cheapest I can find it.
Anyway, one solution would be to buy two 5mm thick plates and weld round the circumference - that seems like it would work out quite a lot cheaper. The question is how would the thermal conductivity be affected by the tiny gaps which would inevitably remain in the centre (the two plates will never be completely flat)?
Is there some kind of thermal paste that could mitigate this, which is very heat resistant? If so how would it deal with being superheated by the welding, and would it contaminate the weld?
And lastly - this got me to thinking about copper bottomed pans - how do they bond the copper to the stainless steel (google is failing me- or I am failing google with poor search terms)??
So 3 sort of related questions:
1.Welded plate- big conductivity problem or naught to worry bout?
2.Super high temp. thermal past - would it help?
3.How are pans copper bottomed anyway??