if you can it would be a great help, even if its something cheesy, just a slogan for why you should wear safety goggles during an experiment.either that, or why you should keep a clean work area.
Yes. I would recommend a BC type because it is easier to clean up after if you should ever have to use it. Remember that the FX is for the use of saving people first, then maybe saving property. Always buy a big one, maybe a 40 BC. Using the FX you will have a huge cloud of white stuff that you can't see through. Stop and wait for some dust to settle and if you use a small FX there may be no more contents to spray if the fire is still burning or hot!
It's unlikely the concrete played an active role in displaying the images. More likely: they added a bunch of little reflective glass cubes, like sugar crystals, to the concrete mix. The little cubes reflect a LOT of light back, making an excellent projection screen. In fact that's what the old screens were coated with. It probaboy did not catch on due to high cost. and 99% of the glass beads are wasted as they're inside the wall, not on the surface where they do any good.
