Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I always use a high grade rubbing alcohol to degrease the parts I paint. (Be careful some alcohols leave residue from the denaturing.)

you certainly didn't get very good adhesion Jim, I know you live on the water (salt water) but if your not having that problem with anything else...then it must be the application in this instance...probably the paint, I see Keith Appleton uses etching primer all the time, I personally don't have any experience with that. I guess i wasn't much help here, but I know we have many members whom can guide you .
BTW ,how many mounting holes are drilled into that base Jim ?

Am certain it has been contaminated by oil or similar, which has stuck on there right through the sanding process.

When i repaint, i prefere to sand or blast to bare metal, wash with acetone or thinner to degrease, and then topcoat straight on there, and never have experienced anything like this on my toys.

I have however used grease to mask old tractorparts and machinery quite often, and the result looks exactly like yours...with the only difference that i aim to be able to peel off the paint in those areas.