foam

hey guys just sharing my muffler i made out of 250mm pvc pipe and insulated with sound lag, a lead lined foam. The end caps are cut a bit rough but still does the job.

Sorry I posted this on the grow room and no one has replied. I built a new grow box out this foam insulation. The foam has a dull sliver and it reflects light pretty well. But I'm wondering if I need to use mylar film on walls instead.

I make a new grow box 3x3x6. I used the foam board insulation and the shiny side is facing in. I'm wondering if that's enough or should I put mylar film on the inside? I seen a comment somewhere that the dull side of aluminum foil reflects more light than the shiny side.which is hard for me to...