Now for the nightmare ....
The aft float switch bilge pump
has been turning one once or twice a day over the last week which is not normal, but it has been raining, so I assumed that water was coming in from leaks
and did not investigate further. 3am yesterday after a late night and a few too many beers the bilge pump
activated, but it had not rained in about 12 hours, so obviously there is a problem ...
Checked the bilges, and noticed water seeping through the hull
close to the sonar transducer. Scratched it with my finger, and the seeping becomes a small stream. There is a small hole corroded through the hull
, it is 3am, I have had a few beers, not much sleep, and there is nobody to help. What to do ?
1. put finger back on the hole to stop the flow and think of the boy and the dyke
2. decide that the bilge
pumps can handle it, and go in search of a temporary fix
3. put a dinghy
patch over the hole, and weigh it down with a sledge hammer. this slowed the leak considerably, and reduced bilge
pump frequency, and gave more time to think
4. get paranoid about the bilge pump failing, and decide 4am is the right time to get out the new spare pump and plumb and wire it up ... just in case.
5. check that the leak is not getting worse, then go on the internet
how to fix holes in aluminium boats while they are in the water.
6. wait until 8am, check that the sledge hammer is still doing it's job, then go for a walk to the nearest marine
7. buy two-part putty for sealing hull leaks underwater.
8. walk back to the boat, put on the wetsuit, and go for a swim in cold murky Sydney
Harbour and hope the sharks are not too hungry today.
9. find the hole on the outside of the hull, clean around it with a scouring pad
10. try to cover the hole with a toilet plunger and hope the pressure will keep it there. it did not get a good enough seal to hold
11. knead a lump of putty, jump back into the water, and try to smear it over the hole. the putty instructions say to knead for 2 minutes, then you have 9-14 minutes to work with it, but after 2 minutes kneading, and 30 seconds swimming the putty was already hardening, and did not stick well to the hull, but did block the hole and did almost completely stop the water flow and after 36 hours is still in place. I did ball up the spare putty and planned to keep it, but dropped it swimming back to the dock
, and a large fish
rushed in and ate it, so he may be needing a constipation cure soon. I have since kneaded another ball of putty to see how quickly it sets, and what consistency it has, and it gets hot and reaches a brittle rubbery consistency after only a minute or two, and does not set further. It is possible that this putty has been on the store shelf too long, so may not be optimal. Personally I would prefer something stickier that sets hard (e.g epoxy), or very rubbery (e.g sikaflex) but this putty did not give me confidence that it would stay on the hull, so I continued working ...
13. ask the boat yard manager if he could get someone to put a spot of weld over the hole on the inside of the boat, but he says he can't weld while the boat is in the water, and I know the wait to haul a boat here is about 2 months, so I need a temporary solution that does not require welding, but is strong enough to sail hundreds of miles offshore
to my planned haulout destination
12. walk to the hardware
store to buy a two part epoxy
in syringes that sets underwater. mix it up, spread it over the hole on the inside of the hull, then cover it in plastic and the trusty sledge hammer for pressure because there is still water weeping past the putty and pushing the epoxy
out of the hole. after 8 hours the epoxy is still rubbery, so not sure it is going to set properly. Should have bought proper epoxy instead of the DIY syringe pack.
13. walk to the marine
store and buy a fibreglass repair kit including mat and polyester resin. if the epoxy has not set after 24 hours I will glass over the hole.
This has all got me thinking about other solutions I could use with what is already on the boat.
A. could put a self-tapping screw through the hole, either from inside or outside the boat. a rubber washer would further improve the seal
B. the hole is near a stringer, so should be easy to put a strip of rubber over the hole and keep it in place with a clamp, wood block, and wedge.
C. it may have been possible to just smear sealant
on the outside of the hull and let the pressure push it into the hole to set.
D. it may have been possible to just hold a plastic bag on the outside of the hull and let the pressure seal the leak
Anyway, it did make me glad of the work I have done replacing bilge pumps and float switches and fitting non-return valves. I now have more confidence in the pumps and in overcoming leaks, which can be a scary thing at 3am even in a marina, and would have been much worse offshore
. Also, when I think about it, the wooden boat next to me pumps much more bilge water in a normal day than I do in an "emergency", so it is good to get this leak into perspective.
I suspect the hull corroded in the past due to flaking paint
and stainless steel
fittings and the void was filled with aluminium oxide crystals, and my recent activities wire brushing loose paint
in the bilge and scraping the hull have dislodged the paint flakes that kept the water out, allowing the crystal to dissolve and the leak to start. My planned haulout will now need to include grinding the old paint out of the bilge, inspecting for voids, welding, and then priming and painting the bottom.
And for anyone considering an aluminium boat ... try to avoid painting it, and try to weld on aluminium fittings instead of using stainless steel
screws and bolts