Got my frame back from the powder coaters last week and went to rebuild it today. The seatpost wont go in. Initially there was some powder coat around the top lip of the seattube so I sanded that off and cleaned it up but it still wouldn't go in. A look inside the seat tube uncovered some shotblast stuff stuck to the inside so I cleaned that all out but it still won't go in. It gets in about an inch then gets stuck. I'm able to hammer it in then hammer it back out. I sanded down the seatpost but it didn't help.
My concern is could the powder coating and subsequent baking in the oven have warped the frame?
As a solution I'm thinking a narrower seatpost and a shim???