Well I hope i have more luck with this post than my last one but here it it is, I just bought a 1984 sailfish 25' there was a lot of sludge on top of the fuel tanks so i removed the deck covers and started cleaning and scrubbing and rinsing , I had both bilge pumps set to the the float setting and i noticed a lot of water would build up around the bottom of the tanks before the front bilge would come on, is this normal ?, why dont the tanks drain to the rear bilge ? does this mean if water gets past the deck covers that a certain amount stays in the bottom of the hull ? please help, I dont want to pull the tanks if i dont have to , but i dont want to have water in the hull either, cant really see to well around the tanks but it look like theres a tube from the primary tank to the secondary tank compartment , thanks in advance :shock:
fuel tank compartments
- Thread starter klutchboy
- Start date
When the boat is gassed to get on plane as the stern drops and bow lifts, the entire bilge stem to stern should drain to the rear bilge pump and be pumped out auto. While standing still at the marina or at drift - different story, thats why the boat has a forward bilge pump.
I am not sure of the exact construction in that hull but there may be a drain tube facing aft. The water should drain towards the rear.BobP said:
Take a look in the bilge rear to see if you can see the drain tube that connects the bilge to the tank compartment. It may be clogged.
If there is one, try to flush it out with a garden hose.
Here' a link that shows you what you're up against. I did not explain it too well the first time, so I'll try it again. viewtopic.php?f=2&t=12899&p=89813#p89813
The long PVC tube positioned on the centerline drains the bilge area below the cabin. It runs underneath both fuel tank compartments, but does not drain them. The only way water may drain from the forward fuel tank compartment is to first drain it into the aft fuel tank compartment. In order to accomplish this, there should be two 1" holes (port and starboard) through the bulkhead which separates the forward fuel compartment from the aft fuel compartment. On my boat, the factory drilled both holes, but some bonehead glassed over one of them, so I had to open it up.
Now that bilge water in the forward fuel compartment has joined with the bilge water in the aft fuel compartment, (in my boat at least) it drains through the aft bulkhead of the aft fuel compartment through the short PVC tube, back into the aft bilge area located below the splashwell, where the aft bilge pump is located. But there's a catch! In order to prevent aft bilge water from running forward into the fuel tank compartments, the short PVC tube is plugged with a removable stopper, access to which is gained from the aft bilge. So then, to drain water from the fuel tank compartments, it is necessary to periodically remove this stopper.
The long PVC tube positioned on the centerline drains the bilge area below the cabin. It runs underneath both fuel tank compartments, but does not drain them. The only way water may drain from the forward fuel tank compartment is to first drain it into the aft fuel tank compartment. In order to accomplish this, there should be two 1" holes (port and starboard) through the bulkhead which separates the forward fuel compartment from the aft fuel compartment. On my boat, the factory drilled both holes, but some bonehead glassed over one of them, so I had to open it up.
Now that bilge water in the forward fuel compartment has joined with the bilge water in the aft fuel compartment, (in my boat at least) it drains through the aft bulkhead of the aft fuel compartment through the short PVC tube, back into the aft bilge area located below the splashwell, where the aft bilge pump is located. But there's a catch! In order to prevent aft bilge water from running forward into the fuel tank compartments, the short PVC tube is plugged with a removable stopper, access to which is gained from the aft bilge. So then, to drain water from the fuel tank compartments, it is necessary to periodically remove this stopper.
thanks guys, that explains a lot, that rear bilge area is not easy to get into, cant see the tubes in there but there is a recessed are under the little bulkhead so i am assuming thats where they come out , time for a garden hose and pvc pipe trick
klutchboy said:
the rear compartment looks like this.....see the main pvc drainruning fore and aft....but also see the little stubby that drains the compartment to the rear bilge....pretty useless though as it only on one side and water gets stuck on the other side of the main drain with nowhere to go...ends up just sitting there and keeps the tank wet....not good.
The later years don't have the bulkhead between the two tanks my best guess is there is a 3/4 PVC to drain the rear tank compartment to the rear bulge and the foreward compartment drains to the front bilge. I'd check the rear drain to see if it's clogged. If you're washing the tanks, whatever goes down the sides will have to rise above the tank stringers before it hits the bilge and unfortunately the stringer acts as a dam. If things don't look right, it may be best to pull the tanks.