We Have Ignition

Houston, we have ignition! After putting 50 gallons in the port aft tank and priming the fuel lines, Nellie started right away. I looked everywhere and found no fuel or raw water leaks--this was the first test of the new exhaust hose too. The Webasto heater, which needs to pull fuel out of the new tanks, worked too. Lowering the height of the tanks by 1/2" wasn't enough to make the existing vent system work. Same problem as before--the tanks' vents are higher than the bottom of the joists.



Since the vent tube must go under the joist and then rise to the tank, this violates the rule that 'the vent tube continuously run downwards'. The pictures below show a way to mitigate the problem. The good news is that drowned vents only effect re-fueling operations, thus the vent line would only need to be cleared prior to refueling.



The vent tube attaches to the top of the tank in the bottom center of this photo. The tube then travels inboard to a 'T'. The right leg of the 'T' goes to the aft tank. The left leg, composed partially of semi-transparent tubing, goes to the cabin-side fitting. The semi-transparent tube rides in copper saddles and will be filled with diesel if the vent is flooded.

A flooded vent can be cleared by lowering the 'T' while raising the other end. Then the 'T' is raised and the fuel drains back into the tank.



What a mess. Time to clean up!

Tanks are Almost Done

Almost done!

Only the clean-up remains to be done.

The bilge is less cluttered now.

More Tank Plumbing

Finished up installing the fuel supply and return lines.

I thought the floor joists were made of teak. However, after installing bigger fasteners in them today, I believe that the wood is what Tommy Chen calls 'Iron Wood'. We know this wood was used as coring for the fiberglassed floor joist stringer and to make the cradles in which the tugs were shipped to the U.S. Iron Wood is very dense and strong. To hold the joists together the factory used 2" #12 ss screws. Many of the screws were damaged when I removed them. To keep this from happening again, and to beef-up the joint, I re-bored and then countersunk for 2" #8 ss screws. The joists definitely feel more secure now.

The main reason the 3" exhaust hose had to be replaced was because it rotted where it sat in the lazarette-fed bilge area. Originally the factory secured the exhaust hose to the underside of the floor joists with hose clamps. Several of those clamps were missing and thus Nellie's exhaust hose had dipped down. Now the exhaust hose is supported every 20"; high, dry and protected from vibration.

Plumbing the New Tanks

Began installing the fuel supply and return lines. I really do like the 5/16" copper tubing that was used. Even after 24 years it doesn't show the least bit of wear. But, because the new tanks' fittings are in different places than in the old tanks, I had to make some new lines. The factory used what looks like brass strips to hold the lines in place. I reused the brass strips and augmented it with copper strips where necessary.

 It seems that industry has decided that 1/4" and 3/8" tube is adequate for most jobs, thus 5/16" fittings are hard to come by. What is available seems targeted at repairs and not new-builds. Thus I had to use two ells which are 5/16" ferrule to 1/4" male-NPT instead of 5/16 flared tube to 3/8" male-NPT. I bring this up only because I thought I preferred tube fittings. They're easy to form in the field and are reliable. The ferrule fitting however means you don't have to flare the tube, thus it's faster.

 Stainless steel fittings were used to isolate the copper fittings from the aluminum tanks. Another choice could have been nylon fittings. They would sit lower than the stainless fittings and would be self-sealing. I put both nylon tape and pipe dope on all the metal fittings. The problem with nylon fittings is that the USCG doesn't approve it for a commercial vessel. So the question is would Nellie ever become a commercial vessel?

Preparing to flare the tube. It's a good thing I paused to take this picture. Note the flared tube cap sitting on the aluminum tank? Well, it's supposed to go on the tube before it's flared.

The original manifold is in place. The copper fuel supply and return lines are too.

In Go the Last Two Tanks

The last two tanks were put in place today. The floor joists were put back too. The new tanks each have a ball valve on the fill line. These were installed and all the new 1-1/2" fuel hose too. The USCG approved hose is expensive stuff at $9/ft. Nellie needed 17.5 feet.



Tank 3, the starboard forward, went in without problems.



Tank 4, the starboard aft, finds its home ok too.



The floor joists going back into place and the fuel filler hoses too. Note the new ball valves for each tank.

Next Tanks Go In

The port aft tank went in a lot easier than the port forward tank. When cutting the old fuel line off the port deck fill I found evidence of water getting below decks via the fill plate. It'll have to be re-bedded. Getting the fuel tank vent line to run continuously upwards is proving to be difficult. The problem is that the line pierces the deck a long way from the tanks. It then tries to run just under and parallel to the deck until it gets to the tanks. The problem is that the vent line bobs up and down as it spans the rafters. Any fuel finding its way into one of the low spots will get trapped.



Tank 2, the port aft, getting ready to go in.



Tank 2, the port aft, just begining to be slid under all the hoses and wires before it goes under the settee.



The only way to remove the 24 year old fuel line from the fitting is to cut it off. A Dremel tool works wonders.

Port Forward Fuel Tank Goes In

Lots of rewiring today. Actually, it's mostly just cleaning up wires that are already there. Got the the new port forward fuel tank in. Sure glad the height of the tank was reduced by 1/2". Even so, had to use the hydraulic jack on the settee.



The new tanks are delivered to the dock. Now just installation remains …



These stainless screws were holding the bilge pump down. Note how the bilge water has eaten them away. The head of the screw was tight against the plastic pump case. The water trapped below it was probably stagnant and stainless will corrode badly in deoxygenated water.



The port forward fuel tank is back in place.

Fuel Tank Vent Blockage

The port vent line had a low point (i.e. p-trap) where it penetrated into the bilge. Drilled 3/16" holes in the floor joists and then nylon-tied the 3/4" vent hose tightly to the bottom of the joist. Had to replace the 1100 gpm main bilge pump as one of the plastic tabs which held it into the strainer had broken off.

Port Bulwark is Retaining Water

Good news. Rebedding the starboard fuel fill plate worked as no water is leaking by it. The port bulwark is getting water inside it. Probably via the hawse pipe to bulwark joint. The water is then dripping below decks via a pinhole leak in the fiberglass. The pinhole leak is 3" outboard of the port fuel fill.