Cleaning and painting a deep bilge

[glmeadows]

I have a Cape Dory 330 with almost 4 feet from the cockpit sole to the bottom of the bilge. There is a roughly 14 inch square access in a floor panel near the engine doghouse and then one just aft of the salon table. When I pull off the doghouse, I have access to the engine bilge. Here's the issue. The previous owner(of course not me) let the boat go and the engine bilge liquid found its way into the main bilge and neither were taken care of. The sides of both the engine bilge and the main bilge are coated with grease which can be cleaned to show the white fiberglass with alot of elbow grease and the right length handle to a mop but, and here's the but, the flat area, being the very bottom of the bilge is black and cannot be brightened with every degreaser I throw at it. The bilge is bone dry having been fully shop vac'd but I CANNOT remove the black grime at the bottom. My objective is to paint the bilge after moving all of the hoses and bilge pumps to avoid putting paint on them. I'm just gonna assume the bottom is clean and put a few coats of primer and a coat of paint and hope for the best.
ANY THOUGHTS ???

[Bellinghamster]

Peeling paint does a great job of clogging bilge pumps, looks terrible and only gets worse.

Having owned a couple boats that previous owners had painted bilges "poorly" and subsequently had paint adhesion issues, I would strongly recommend that you don't do it unless you can be REALLY sure you have it perfectly clean/degreased, then rough it up with 40 grit sandpaper or a grinder, use really good primer and paint, or better, gelcoat. Gonna be tough 4ft down a 14" access hole unless you're really skinny and like hanging by your ankles.

I just finished a similar job this summer on my GS50 bilge while the engine was out (repower). Ground it all smooth/clean, did some glass work to seal the (not quite) encapsulated ballast and gelcoated everything, mostly done hanging upside-down but not as deep as yours and with better access... It's awesome now, but was a LOT of uncomfortable work to do it well.

[Nord Sal]

Hoping for the best sounds like a losing proposition. Could you use a scrubber pad or sanding black mounted on a long handle, i.e., a pole sander?

[glmeadows]

Yes, a major concern for me is peeling paint and what it could do to my bilge pumps. The boat's smell has been one driving motivator to paint but the access to clean or paint leaves me wondering if I should consider cutting another access hatch in my cabin sole but that could be, for many reasons, not a great idea. I've seen some oscillating buffers/sanders with a long extension rod but I'm not confident they have the industrial strength required. One way or another, I want a clean bilge even if I have to rip up the whole cabin sole and put it back in place.

[Cheechako]

Just leave it. It will be more of a mess if the paint buckles off. Unless of course you plan to have a wedding of leprechauns in the bilge....

[glmeadows]

All good advice and suppose we can't always get what we want. What I might do is put a small bilge pump in the engine bilge preventing further grime from finding it's way to the main bilge and call it DONE.

[wingless]

It sounds possible to properly rough up the bilge for proper adhesion.

Other than (your) time and cost, nothing wrong w/ properly doing that project.

Definitely do not make additional openings to permit painting the bilge.

FWIW, there were spots in my various bilge compartments that had poor gel coat adhesion that I have fixed and those have held up fine. Here is one in my anchor rode locker that has been working fine for years.