Another one of those things many already know, and others might be pleased to know.
Let's assume you need to slather a layer of epoxy/micro on some convex part like elevator tips. You should try to slop on what may seem like too much micro with the first application, because then you get consistent density and a better finish later. You're not looking forward to the job because it means sanding away a lot of excess material in order to shape the part. Slow and dusty, yes?
Naaa....everything in life is timing.
Epoxy/micro (and polyester filler for that matter) goes through a stage during cure when the filler is quite firm, yet soft and easy to cut, much like dried out cheese. The actual time from mixing depends on the epoxy and hardener you're using. For the popular West System resin with slow hardener, figure five or six hours at 70F....let it go until you can't quite dent it with your thumbnail. It is still way too soft to sand without clogging the paper; what you need is a 12" vixen file. Hold it at an angle and stroke across the part, sort of like an airplane in a 30 to 45 degree sideslip, and you'll be rewarded with nice shaved flakes and curls of excess micro hitting the floor at a rapid rate. Knock it down to a near-profile and shape, then go have a beer and come back tomorrow with the sandpaper.
Try it, you'll like it.
Let's assume you need to slather a layer of epoxy/micro on some convex part like elevator tips. You should try to slop on what may seem like too much micro with the first application, because then you get consistent density and a better finish later. You're not looking forward to the job because it means sanding away a lot of excess material in order to shape the part. Slow and dusty, yes?
Naaa....everything in life is timing.
Epoxy/micro (and polyester filler for that matter) goes through a stage during cure when the filler is quite firm, yet soft and easy to cut, much like dried out cheese. The actual time from mixing depends on the epoxy and hardener you're using. For the popular West System resin with slow hardener, figure five or six hours at 70F....let it go until you can't quite dent it with your thumbnail. It is still way too soft to sand without clogging the paper; what you need is a 12" vixen file. Hold it at an angle and stroke across the part, sort of like an airplane in a 30 to 45 degree sideslip, and you'll be rewarded with nice shaved flakes and curls of excess micro hitting the floor at a rapid rate. Knock it down to a near-profile and shape, then go have a beer and come back tomorrow with the sandpaper.
Try it, you'll like it.