Painting Inside of Refiitted Boat w/ Multiple Substrates

Hello Everyone-
I am working on my refit of a 1970's owner-finished (kit) 21' (6.4m) sailboat. The cabin was stripped of berths and galley furniture to clean and repair the boat. I am about done with structural items and am beginning to think about cosmetics.

The interior features that I have in mind to paint:
-old painted fiberglass and old painted wood
-new plywood and pine furniture wood primed with a water-based white (done several years ago)

Most of the repaint will be the fiberglass cabin walls above the hull to deck joint and ceiling that already have some sort of almond-colored paint. I would also like freshen up the newer berth tops which were only primed with water-based during installation.

Does anyone have recommendations for new coatings and testing compatibility between existing and new? It will most likely be brush, roll, and/or roll and tip as the space is quite small and I don't see myself masking off stuff and suiting up to spray in there. I am not looking for state-of-the-art fine finishing but stuff that will allow me to coat what is there without having to grind existing back to bare wood and glass (primer or tie coat would be totally fine as needed).

Here is a picture or two, the galley cabinets sides being test-fitted and the artist's rendering from this morning. Cabinets are now assembled and face-frames have stain and varnish, paint and tabbing to follow. The dark gray in the render will be marine carpet, the main paint job with be above that and under the cushions.

Thanks!

 

The standard old-new paint compatibility test is to -
-Score an X on the old paint
-Place a small rag soaked with the solvent used in the new paint on the X
-Cover with plastic film for 24 hours

If no blisters or peeling then over coating is possible

Primers don't have UV stabilizing ingredients. I would not paint over Years old priming.

A full scale primer-bond-tie coat would be a great idea. It would minimize any incompatibility issues and even out the finish coat.

I don't foresee issues with basic paints. Two part, catalyzed or lacquers could have issues.

Good luck

 

Thanks @Blueknarr
At work we used to do a similar crosshatch cut test for dry film adhesion. Cut some hash marks and try to peel off the coating(s) with a certain frosted cellophane tape.
I just got done priming the cabinets' plywood with an alkyd enamel (Rustoleum) so I did some tests blocks with the remnants in the roller, one on each potential surface (almond painted FG, red painted FG, plain epoxy tabbing, and the primed wood) with an X to one side.

 

I trust Rustoliem to provide a decent finish

Testing with the solvent-mineral spirit- is far more effective than Testing with the paint, because the solvent evaporates to quickly from the paint.

Either way, the only issue I foresee with Rustoliem is over the very old primer.

 

I will set up the more organized solvent-rag-plastic test next time I am in the boat. I had to spray for hornets inside the boat earlier this year and the primer below the nest did get soft and wrinkle from the petroleum distillate used to carry the active ingredients. Perhaps if I'd cleaned it up sooner that damage and the lingering smell like kero or diesel would have been less.

PS I remembered I had some recent off-cuts from the side berths and set up a test panel...

 

I took the tape off the test blotches and it pulled significant amounts of the white paint off the plywood. It looks like I am in for some sanding and scraping before re-coating.

 

Test panels the day after. The SPECS thinner did soften the paint a little, waiting to see if it hardens back up, but it's not as visible as the others. The samples were 'B' sides that did not see the same exposure as the compromised 'A' sides that were face up to sun and humidity, etc..