Any tips on keeping the paint from “bridging” in the corners?
Caulking is not an option.

Spray lighter passes ,which may not be easy in a small box . Or try easing the edges a bit before assembly with something like a Fastbreak [ from FastCap ]

Thanks. We do ease the edges to 1/16” round-over but it still happens.
Will have to try different spraying techniques.

And why is caulking not an option?

You could try using a a wide putty knife/drywall blade between coats to get rid of any cobwebs that pop up. You risk damaging the finish though if you get to frisky.

cheers

is there any way to take the back off?

I spray with the back off.
I don’t caulk because of the risk of shrink cracking.
I have used the putty knife method but looking for something better.

What kind of joint?

Any inside corner.

Spray the parts then put the cabinet together?

We already break the cabs down as much as possible before finishing them. We build full face-frame cabs and hide as many fasteners as we can. So in many cases it would be impossible to completely take them apart.

not sure what your shooting but thin it and slow it down and should lay out.

I've been caulking doors/drawers and inside finished cabinets almost 20yrs. The only time I had an issue was when I didn't let the caulk dry overnight and I've never had an issue with a cabinet. Doors/drawers move,cabinets not so much. I hate caulking but it looks much better. Certainly better than intermittent spider webs or an uneven shadow line.

Whenever possible I do spray without the back or in pieces. But it's not always possible.

my2cts

Thanks for all the suggestions. So far I realize that I’ve tried everything you all have.
I may try caulking. In the old days of oil base I did caulk, but using post-cat now it makes me nervous. I’ll do some small test areas.

if you are making your own cabinets prefinish the interiors...

Anytime we have a cab with a painted interior, we paint the pieces prior to assembly. We assemble the box, attach the face frame, then mask the interior while we paint the frame. If we painted it after assemble, I would prob use caulk. I have never had an issue with using caulk under post cat.