Large whiteboard for LED STRIP heatsink

Hey guys I got this large white board like what you see in classrooms etc, and was wondering if it would be suitable for a heatsink for a bunch of Samsung 2 foot strips, it measures about 1.2metres X 2 metres long, it looks to be made from unpainted galvanised sheet metal on the back and probably the same on front but it has been painted white for obvious reasons and the inside is unknown material samwiched in-between the two sheets of metal and the outer framing is U channel aluminium which holds it all together, I reckon I could put 1000 watts on it and run it over a 4x8 area what do ya think?

The interior of the whiteboard is basically an insulator so you only have one side that is dissipating heat. The backside will a fraction of the front. If you have a fan blowing on the front you could get away with it.