Painting the 'nether-regions'

Of all the tough jobs on a boat, painting bilges and the interior of lockers might be the most un-rewarding.  Perhaps this is because nobody but you will ever know how much toil went into this...who looks in your bilge?

Most places in the world, when confronted with this need, you would walk into your local supply house and pick-up a gallon of Interlux Bilgekote or Pettit EZ-Bilge...well not in NZ.  I have asked dozens of people in the industry and they all look at me like I am from Mars ("Canada actually").

My bilge is very clean, but the gray gelcoat on the hull, and the gray enamel on the plywood ribs is worn out and looking old.  The interior of my lockers are all a bit dull, and in need of some attention.

I have therefore been looking for an all-around primer and topcoat that will treat all of these areas, as I do not want to end up with a lot of half-empty paint tins.

I also have the challenge that the inner surface of the bilge/hull is almost impossible to sand, as it is heavy mat, complete with a waffle-like pattern.

I stumbled around for quite a long time until I cam across a company called Zinsser (a division of Rust-Oleum), who produce a product called "Bulls Eye 1-2-3 Water-based Primer"...here is what they claim:

About Bulls Eye 1-2-3® Water-Base Primer

There’s a reason Rust-Oleum Zinsser Bulls Eye 1-2-3® Water-Base Primer is our most popular primer. This premium, whole-house primer-sealer provides outstanding performance indoors and out, with low odor, great flow and leveling and a flexible, acrylic formula.

• Water-base primer-sealer
• Interior and exterior
• Sticks to all surfaces without sanding
• Seals stains, graffiti and tannin bleed
• Mold & mildew resistant film
• Rust inhibitive – great for new metal
• Fast 1 hour dry time

Note the bit about "...sticks to ALL surfaces without sanding...".  You can use it to prime ceramic tiles if you want...should work wonders on the glossy bilge gel-coat.

I am pretty excited that this primer will deal to the variable surfaces I want to treat.  It has a very high solids count, and is even anti-mold and mildew!

In terms of a top-coat, I am going to use a gloss-white marine enamel everywhere, for ease of clean-up and identification of any leaks or problems. 

I'll use this post as the work commences...so watch this space!


UPDATE 25/8/13:

I have decided to buy some white-tinted polyester "flow-coat" to apply to the actual bilge area, from the keel bolts up the the turn in the bilge.  I want to guarantee improved water-resistance in this area, which can be subject to standing water for periods of time.

This is a purpose-built product for this sort of application.  Following the flow-coat application I will prime and paint as described above.  It is essentially a polyester resin that cures hard instead of tacky.  Flow-coat is gel-coat with a wax added.  The wax seals the product at the top of the layer and allows it to harden fully.

Before:

An incredibly-clean bilge

I spent several hours scrubbing the bilge with Simple Green, then a strong solution of sugar soap.

UPDATE 31/8/13 - Painting the Flow-Coat

I gave the entire bilge a final sand a wipe down tonight, then mixed up 100mL of polyester flow-coat and hardener.  I used a disposable brush and applied the flow-coat the the very lowest portion of the bilge (where the keel bolts are), and up the sides 3".

I didn't consider painting the entire bilge with flow-coat because it would have required a lot of material (it goes on very thick, and does not spread very far).  I also decided not to flow-coat everything because it is a horrible product to work with (as are all polyester and epoxy resins), you must work quickly or even 100mL on a chilly night will kick in the cup.

The only place water will ever sit for more than a day is at the very bottom of the bilge, which is where I have applied the added protection of polyester resin ~ Flow-Coat.

Update - 01/09/13

I have sanded boat bottoms to gel coat with a hand sander, I have had a holding tank spill onto my head as I lifted it out of a hull, and I have put a sailmakers needle through the palm of my hand...but I have never done anything so difficult and unpleasant as painting the bilge...it is incredibly exhausting and trying. 

This is the progress so far on the primer coat, removing hoses as I go to avoid a total hack-job. 

Update 5/9/13 - Almost finished

I have applied a coat of gloss enamel this evening, so all but the last "section" below the companionway is complete.  I will have to come back to this section as otherwise I would have painted myself into a corner (literally).

The end result is as good as I expected, but as mentioned before the effort was perhaps disproportionate with the benefit...not sure.

AFTER  

An incredibly-clean bilge

Final touch ~ bilge pump re-installed.  I bedded it in silicone, no more screws into the f-glass