I have a ton of 3d prints that I have ready to smooth out. I have XTC 3D smooth on and was about to use it, but was not sure if I should sand it first. I would like to eventually spray paint it and apply Rub and Buff to give it a metal look. Am I barking up the wrong tree here?
xtc3d is great for smoothing PLA. It is self leveling, so it fills the layers very well. It is an epoxy, so no need to sand. You may want to sand it lightly after it hardens.
FOLLOW THE INSTRUCTIONS. Mix exactly. Use very, very thin layers, it runs. So more layers NOT thick layers.
Ditto what @Perry_1 said, XTC-3D is great stuff, but it’s a nightmare if you get the mixture wrong and don’t plan your painting (i.e. get everything ready, how to hold the model, where you’re going to let it cure, etc.). Make sure you use exactly the mixture specified. Get it right and it produces a great surface.