I use 30-minute epoxy, and they come out great. Mix as much micro-balloon dust into it as possible. That means past what you think it ought to take, but do it quickly. The working life is not really long. I use a Popsicle stick sanded to a radius I need to get the size fillet I want. It comes out pretty smooth, but needs some sanding. It takes a little time to sand, with your abrasive wrapped around an appropriate dowel, but if you've used enough micro-balloons, the final shaping is minor, and finishing is pretty easy. Added strength is valuable. Contrary to what some others have posted, I LIKE the process and results. I'm pretty hurried now, but if you search here by topic or my name, you'll find pictures of the process and results.