Sanding grit recommendations

I am buying a number of custom size interior doors for a builit-in robe from Hume doors. I am assuming that they will come reddi-coated, but the edges will be cut locally to size, so I intend prepping / sealing /undercoating the whole door with a 3 in 1 paint before applying the final two coats of waterbased full gloss enamel.

Can anyone please advise the sanding grits that should be used at each stage? eg 120G for the door as it arrives, then 180 after the priming coat, then 240 after the first glossy finish coat ??

For the raw wood you need to sand with 180 grade.
To sand the coating you can use the 280 in the prime coat and 320 or 400 before the last coat.

Good luck

thanks wisno, that sounds good