Maybe for the sides i'll go get some more melamine to help aid in the strength of the tubs, good call, hahaha. As for overkill. I don't know how your are able to get a good ambient temp with your tubs. I have used a few different homemade racks and the ambient temps are always the same as the room temps. The hot spots are the only area that gets heated. I guess your lucky. I know oil filled radiators aren't expensive to buy but i'd rather spend money on back heat than the monthy expense of heating a whole room. Thanks for the thoughts and opinions.