Whats the best heat deflector material?

[michael1703]

I have a log burner which has a flue which disappears up the chimney, but it goes through a big sheet of asbestalux material

A lot of heat rises from my burner but i would like to deflect it back down rather than have the majority of it go up the chimney

any ideas what has the best heat reflective properties*



* gold isnt an option due to budget restraints

 

[rtbcomp]

Polished stainless, could you get a piece big enough from a scrap dishwasher?

 

[ngt]

Cars use aluminium sheet sandwiched with thin insulation with the inside polished mirror finish.
Thats at their exhaust manifold (example MINI r56 turbo)