Glueing painted parts together

   Hello, it isn't recommended. Plastic cement " welds" the parts together, paint creates a barrier between the parts preventing the glue from performing.

   It is best to glue parts before painting or clean the mating surface of paint.

     I have had luck with CA (super glue) it works on a different principle than cement, NOT RECOMMENDED for clear parts. Hope this helps.

The liquid cements like Tamiya Extra Thin melt everything including paint,so I will apply it sparingly to a painted joint and it works fine,never had a problem,never had a mess that a little touch up couldnt fix.

I always clean at least some of the paint away from joints.  If the join area is small I scrap the paint away.  For that, I keep an X-acto handle with a used blade in it.  When I replace the blade on my primary knife, I then transfer that blade to my scraping brush.

For joints that have more surface area I take a shortcut and just dimple through the paint in a few spots with a drill in my pinvise.