[dsraven]

the sil sand can cause problems with paint adhesion due to it's silicone base. it also leaves a profile that will need to be sanded down prior to epoxy primer coating. personally I haven't had the paint adhesion problem although I have sandblasted a few vehicles in my day prior to paint. maybe it is because I have cleaned and sanded so much after the blasting and before the epoxy primer.this is my regimen
pound out the larger dents etc
sandblast
bring inside to warm dry shop
do basic metal bodywork-pound out the big stuff that may be left or found after blasting old bodywork
clean liberally with silicone wax and grease remover and clean rags
sand the area to knock down the blasting profile
spray epoxy primer
do finishing bodywork and any small amounts of filler
spray another coat of epoxy primer to cover any bare metal parts and seal the area
spray primer surfacer and block sand. spray high build, block sand, repeat
the filler should go on over top of epoxy because filler is a porous material and has an affinity for moisture so there should be a barrier between it and the bare steel. it would be best to do a smaller part of the project at a time. that way you can control the time between blasting and epoxy coating. if you have a big project that gets blasted all at once then you could epoxy the whole thing and then do body work and open to bare metal as you do the smaller areas. then epoxy those parts as you finish them
just my method, right or wrong