I have a part for a chair that I need to make and thought making it out of putty or epoxy may be a good way to do it. I am looking for some suggestions on material. I was going to make a mold from one of the others that is still good. The part is a plastic piece that goes on the bottom of the chair. (Part no longer available from the manufacturer). These sit outside so between UV rays and age, they have dried out and discenigrate when you sit on a chair. The key is to be strong enough to hold our weight but have some give so they don't scractch our deck (made from composite plastic boards) and hopefully hold up to UV rays. Suggestions are appreciated.