Aloha 32 Bilge Drainage Project

Ever since I read “Mortar in the Bilge” by Graham Thomas, I wondered about the aft-most keel-bolt on my A32. From the direction of the bilge hatch, I could see a piece of rusty steel with the nut on top of it, and a few inches behind it, a fiberglass floor timber. When I explored the drainage hole from the engine compartment, I found stagnant water. This puddle of water collected because the drainage hole in the floor timber was clogged, and there was no way of reaching the problem area from either end. I decided to router out an inspection hatch to be able to look at the keel-bolt and to resolve the drainage problem. I made the third floor hatch the size of the other two, so that the two long edges of the new hatch would sit on the stringers.

What an ugly sight it was! This area hasn’t seen daylight since the boat was built. The drainage holes on both sides of the floor timber were the very rough. Oily sludge collected on fallen debris, run away nuts and engine enamel flakes that were caught by fibreglass strands and hard spikes. Only a small amount of water could seep over the top of this dam. Any spill that happened at an oil filter or diesel filter change ended up floating on top of the “reservoir” behind the blockage. I figure this puddle never had a chance to dry up, so it froze there every winter. In the summer, the floating oil covered the walls of this chamber. On the keel-bolt side, at the exit hole and behind the steel cross piece, there was a hollow area with no drainage. Unfortunately, the exit hole reached down to the bottom of this pit.

After cleaning up the area, I found the steel cross piece in perfect shape. I will get rid of the rust and put some Tremclad on it. I don’t think it would be smart to glass it in. With the drainage problem resolved, and the floor hatch coming off every winter for ventilation, that steel piece should be much happier.

The close up of the hole shows the oily, wet fibreglass mess at the bottom of the tunnel. The hollow inside of the floor timber extends toward the stove area and toward the nav table on the other side. It is impossible to clean it out.

I allowed the tunnel to dry out, and slightly enlarged the holes on both sides to fit a 2″ PVC pipe. With a little epoxy and glass, I sealed the gap around the pipe. Once this seal was done, I started to pour in epoxy to create a new and level bottom that will ensure good drainage. On the stern side, the epoxy has not reached the pipe. I will have to pour in about 200ml of the stuff.

Between the glassed in steel piece and the floor timber the pit is filled in with epoxy. The water will drain on both sides.

The epoxy puddle on the stern side is shallow and goes quite far back. The tunnel pipe is not horizontal, so on the exit side, some epoxy flowed in and leveled the bottom. Just to be on the safe side, I drilled two vent holes into the floor timber. I can seal these later when I know for sure that there is no moisture trapped inside.

The rest is cosmetics. I have to put polyurethane around the new hatch area and then give the entire floor a top coat. Once the stern side epoxy puddle is level with the pipe, I’ll paint the repair area with grey bilge paint.

Written by by Zsolt Kecskemeti