I have been given a piece of art to frame. It is comprised of 16 individual 4" ceramic tiles mounted to 1/2" cement board. The surface is so wavy that you cannot use regular molding. But if I use a float frame (the back is even)- how would I mount it -adhesive would be permanent so if the frame broke there would be problems. The whole thing weighs about 10lbs and is 18x18".