I don't know much about the technical aspects of epoxy, vinylester(sp), and polyester,  but I do know, after having a fire in my shop during the building process, that the prepreg panels did very well in regards to not supporting a flame. 

 

Although the material was damaged and, thus, not used, it in itself did not support a flame.  It looked just like the Lancair video flame/burn demonstration.  The material did better than the gypsum sheetrock on the walls.

 

The sheets of white foam core are another story.  They real took-off; not much actual flame, but kind of melting and tons of black soot smoke.

 

The fire turned out to be physically (not mentally) minor.  Had it been another type of material instead of epoxy prepreg, maybe I may have lost the shop and airplane?

 

Gary Edwards

LNC2 N21SN