Just a thort ifg you are getting a reation with the paints , it could have to do with , using acrylic laqures over enamels,
It can also be caused by othere things like prep and not letting it set right but if you are using acrylics over enamls , make sure the enamel is cured totaly and for the first few coats of the colour do a real light dusting of paint from a further distance thatn usual, and repeat for at least 3 coats and never layer it on in one go , it taes paitence but its better then having to strip the whole thing this way the paint is almost dry when it lands and asftr a few coats the dusted on paint creats a solid layer for working with,
Also what paints and colours are u using
It can also be caused by othere things like prep and not letting it set right but if you are using acrylics over enamls , make sure the enamel is cured totaly and for the first few coats of the colour do a real light dusting of paint from a further distance thatn usual, and repeat for at least 3 coats and never layer it on in one go , it taes paitence but its better then having to strip the whole thing this way the paint is almost dry when it lands and asftr a few coats the dusted on paint creats a solid layer for working with,
Also what paints and colours are u using