Okay need two more pieces of advice. How do you stop Laminating resin from gumming up your sandpaper and second what is the easiest way of getting rid of the wild threads when you wrap the rails?
when working with lam. resin i try to sand as little as possible. the best tool for cleaning up lap lines is a small angle grinder w/50 grit discs. this buzzes out the bumps in a quarter of the time. if no grinder, then i like to use a small surform and single edge razors. you can use the surform lightly and it will shave the resin nicely. single edge razors can also shave down the bumps pretty well. keep using fresh blades and you will get quicker, better results. i use sandpaper at a minimum. maybe for a quick smooth out after i have done the above. sandpaper tends to smear more, and cause odd scuffs. try different things and see what works best for yourself.