Roasting lids for full sized sheet pans?

Roasting lids for full sized sheet pans?

I’ve got Fibrament D baking stones en route that fit into full sized sheet pans.

The bakery only has a convection oven and I have been limping along using a combination of 5 Quart Lodge double dutch ovens and heavy stainless mixing bowls on top of my present baking stone.  There is quite a difference in the browning and crust between the cast iron and the upside down bowl/stone combo. (Cast Iron far superior) i don;t think the bowls are heavy enough and perhaps don’t seal up nearly as well as the Lodge cast iron. 

Is anyone aware of roasting lids that are the size of full sized sheet pans (18″-26″, I think). If I can’t find anything I think am going to have some made out of 1/8 inch stainless.

If my custom lids get a good seal on the stone/sheet is there any reason not to expect a good result?

Do you think 1/8 inch stainless would radiate enough heat to the inside? Is that a factor?

Comments or suggestions? 

-Thanks

Source: Fresh Loaf