A/R Coating is usally applied by machines in a dust free environment. I don't think a spray would be available. A/R Coating usally scratches extremely easily - all you have to do is look at it the wrong way and it scratches. I think rob was saying that they had to put a hard coat over it. All of this will be pretty expensive to do. I have heard of a company that can put a titanium A/R coating on thats a few nanometers thick - you can scratch it with steel wool all day and not scratch it - but it would melt the poly.

Sean