Boat Buzz

My 1956 twin hemi engine room is dark, the interior hull sides are painted with original grey alkyd bilge paint and the bulkheads are sheathed in Celotex sound deadening dingy colored material. All is original. I want to paint it white I think, accepting that the engine crankcase gases will yellow it eventually. I don't want to remove everything attached to the bulkheads and can paint nicely around installed accessories and wires. Otherwise, I would cover with a SoundDown brand white aluminum and rubber material. I'm trying to avoid that amount of work. So, what paint will penetrate the brown celotex without created a solvent fire hazard? Celotex producer could not answer the question and referred me to paint contractors. Can I seal with an acrylic sealer and top coat with latex mildew proof cabin paint? What about the grey interior hull sides?...I know alkyd primers with latex would normally do the job, but I want to maximize fire retardancy.

I think a good latex primer/finish would be fine on the Celotex. I'd stay with oil based products on the wood. Wet wood doesn't dry out well and breath under latex. You can install automatic fire suppression systems in engine compartments. It's a wise thing to do. I have a Halon type system above the engines and another under the aft cockpit above the fuel tanks.

It seems to be a tradeoff between mildew proof latex like Petite cabin paint, great stuff!! or the high solvent Interlux bilge paint in white color. I'm questioning how breathable the solvent based bilge paint will be when they suggest an epoxy primer follow by two coats of their paint.
I wish more folks would weight in with personal testimonials.
Re: fire suppression, yes, I've got a Halon system too.

sort of off subject, but isn't halon outlawed now or obsolete at least? I thought there was a new gas?

sorry but I have no helpful info regarding the paint options....

John in Va.

Halon cylinders are not re-fillable any more. EPA Still meet fire supression requirements for small craft.

Let's start a seperate thread on halon fire suppression systems....but to my original posting regarding engine room paint here is what I've discovered:
I spoke with the Interlux technical team today as several of them were riding together to a meeting, so I had a real concentration of expert opinions. They said that the wooden interior hull sides of the engine room would best be painted with an alkyd enamel such as their "Bilgecoat" paint (in either grey or white semi-gloss). This alkyd they said would allow more transference of humidity from the wood especially in that bilge area under the waterline. The Polyurethane finishes do not "breath", nor do epoxy nor do latex finishes. No primer is required on pre painted surfaces, although thorough cleaning, sanding and deglossing are needed for adhesion. Recoating without sanding is possible within specified times. My second question was on the celotex materials on the bulkheads of the engine room. For this they had no experience or recommendation so my plan is to seal this spalling papery material by spraying an acrylic masonry sealer using a hand spray bottle. I have used this process on 100 year old brick mortar before painting. Then I will prime and paint with "Bilgecoat" The bilgecoat paint is more immune to the smoke and crankcase gases in an engine compartment and perhaps will tend less to yellow. In the end, any brightness from this paint will be a huge improvement over the dark grey engine compartment existing.

Keith, I used the Interlux Bilgekote in my bilge without priming first. It covered nicely and has held up well. It's stinkey stuff when wet so set up a fan for ventilation and wear a respirator. The fumes will make you loopie if you don't. Gotta love a freshly painted bilge. Happy Painting!

After months of calisthenics in the bilge, I finally finished cleaning the engine room and painting. I used Interlux white mixed 50/50 with their flattening agent to create an eggshell finish without glare. I did the same with the light grey bilge paint. Everything below the waterline inside is grey. I also repainted and detailed the engines and accessories. Now, finally after years of ownership, I can glance down into the engine compartment and everything is clear, bright and makes sense. This is a safety issue too since I can see potential problems quickly. See photos.

Keith, haven't heard from you for a while and now I see why. You've been in the bilge for a year. The bilge and engine room has got to be the most difficult area on an old wooden cruiser to paint, but what a difference it makes. Thing just seem to work better and engines run better when everything is all cleaned up and fresh. Those hemis are looking good! Nice Job!

oh yes! Great Job...tough job...looks great....need to take a ride in that ship.

John in Va.