Monday, June 12, 2017

_____________ DOING SUMP THING ABOUT THE FUEL TANK _____________

Shipmates, it was suggested to me by Geoff the diesel mechanic that the best thing I could do for 'Mariners' engine would be to put a sump on the bottom of the diesel fuel tank. The idea is to drain the sump regularly to get rid of any water and other fuel contamination that may occur. When this excellent suggestion was made I sighed an audible sigh as I have taken the diesel tank out a couple of times before and know well the gymnastics that are involved.

In the above photograph the old bugger is lying on his stomach under the cockpit exactly where the diesel engine sits. The fuel tank is at the back of the engine bay behind the engine. I took this photo to give Terry the Stainless Steel fabricator some idea of how the tank is fastened at the back with its long metal straps. I thought that I might modify the fastening system but have decided to 'leave well alone' and simply repair, sand, repaint and re-use the existing system.

When I cleaned the tank out I readily saw the sensible logic of having a sump installed. There was a cup of vile looking sludge in the bottom of the tank. Regularly adding diesel additive to the tank and draining the sump every month or so should keep the fuel clean and keep the engine reliable. The fuel tank has now been removed and is in Terrys workshop awaiting modifications. Tomorrow I will clamber into the engine bay yet again with a vacuum cleaner, a wet rag and bucket.

Shipmates, if you are in your 60s and need a workout that involves contortionary stretching of an extraordinary nature then remove a small diesel engine from beneath the cockpit of a small yacht. The head banging; shin, knee, knuckle barking, sweating, back pain and profanity come at no extra cost.

7 comments:

Ben said...

This is typical the kind of work I always call “ you should let someone else do it”.
Diesel fuel and moisture from condensation does a remarkable job of making sticky things.
By the way, do you have a duel fuel filter that you can switch on the run? A friend of mine installed it after he almost crashed on a pier because of a failing engine, due to fuel filter problems.
Keep up the good work 😊

Alden Smith said...

Ben, I agree with you 100%. That is why Geoff is doing the work on restoring the engine and Terry does all the stainless steel fabrications on tanks etc - But I have been left to do some of the installations (The bow fitting) and some of the removals (The diesel fuel tank). If I had been able to get the boat up to Opua in the Bay of Islands the whole deal would have been done by a well set up professional team (at a lot more cost) so I am dealing with one diesel mechanic and his son. They know what they are doing but I get left to do some of the peripheral work.
I do have a single fuel filter between the tank and the engine. I will ask Geoff (who errs on the side of safety) if he recommends dual filters - if so, we will install them.

Don said...

This is "boat owners torture" and you should be very well experienced in it, after rebuilding the Starling before sailing. Now you own a keelboat the work is different.But I assure you after it is complete, the 2 months on the hard will mean that this summer you will have some very safe and satisfying cruising.
I run a single engine launch and have followed Len Gilbert's (Diesel Diary) advice since I built it. Having a sump you can drain on the tank is a very good way of ensuring safe fuel, you will be surprised how much water ends up in your tank - just like an aircraft you should check before every departure or at least once a month. Use one fuel line with two fuel filters - a Racor and a standard diesel filter (cartridge type). Makes sure you have easy access to them so you check them often. My launch uses a Racor with a red micron filter, then as it is a Toyota diesel a standard diesel automotive filter. I change them both every 250 engine hours. If you drain the tank regularly, drain the bowl of the Racor then you should never experience a blocked fuel filter. Love your boat and the work you are doing is worth it.

Alden Smith said...

Don, thanks for taking the time to comment, give me some encouragement and some sensible, experienced advice. When I built Mariner all those years ago I did everything - hull, decks, cabin, interior joinery, melted and poured two tons of lead for the keel, drilled the keel bolt holes, fabricated the mast,installed all the fittings etc, etc, etc - BUT! I didn't install the motor and I haven't really been a good boy regarding maintaining the motor etc - Knowledge of motors (cars or boats) is one of my blind spots really, so thanks for the advice re filters and the frequency of draining off the diesel, 250 hours sounds like a good amount of time.
The diesels single filter which has a water trap at the bottom of it is easily accessible and I will run the diesel tanks drain from the sump forwards so that it can be operated easily.

I have always tried to keep the fuel tank topped up to minimize condensation but when I took the tank out and drained it I was surprised to find not a lot of water, rather a lot of sediment and a gelatinous type of substance. Someone told me that diesel actually breaks down over time into stuff like this if it gets a bit old.

The repairs to the keel area and the restoration of the motor will be the last time I will do this kind of hard arsed work (I spent today sanding under the hull fully kitted up in googles and mask) as it's bloody hard work and I'm beginning to feel my age!

Roll on at least 10 more good sailing summers and plenty of great cruising !!!!!!

Alden Smith said...

....... and Don, I am going to install a couple of meters - an engine hour meter and a battery meter that indicates its charge level. Any advice from you (or anyone else for that matter) would be appreciated.

Don said...

Alden, I knock out 250 engine hours in about 18 months.
I think if you sail a lot, you may take longer......so you may wish to do the filter change more often. Filters are cheap (compared with other stuff on your boat), and keeping them fresh is a good practice. Yes I get little bits of that black sludge - formed I believe at the junction of diesel and water. Finish this refit and you will be ready for 10 good years sailing the coast and you are located on a great part of it. Might see you up north in late January.

Alden Smith said...

Don, I do sail a lot. I only use the motor to get off the mooring, through the lifting bridge and down the river usually to where Limestone Island is. This distance (about an hours running time) charges the battery up a bit and gives the motor a bit of a run. So you are correct, it will take me a lot longer to run up 250 hours - so changing the filters often is good advice.
It would be good to catch up if our paths cross this summer.