I'm finishing off a turtle table that will have indoor-outdoor use for the next several years (hopefully). In the little inormation I can find, others have recommended the use of polyurethane products. Given this is an indoor-outdoor model, I bought Helmsman Indoor/Outdoor Spar Urethane (clear satin). Before I apply it I would like to get any additional thoughts on dangers in using this product. I've read recommendations about using deck sealants on outdoor cages but don't want to make an irreversible error. If you've used it or a similar product without problems please let me know. Conversely, if you know of research indicating dangers please point me in the right direction. Thanks!