Diesel Fuel Tanks

[Target9000]

I'll post it for you. =)

[Jeff888]

Originally Posted by Capt Allan

Salt water.

What are you treating your fuel with?

[CarlF]

From your description, this is almost certainly good ol' everyday bio fouling. A mixture of bugs, algae, waste product, mold, etc.

The only sure fix is to drain the tank and then clean through an inspection port with brushes and rags and spray. If you have an 8" or bigger opening in the tank this is the way to go. If you don't, you might consider having one installed. Not very hard.

The 2nd best is to hire a commercial fuel polishing company that will circulate the fuel through filters and try to blast the crud off with pressure wands stuck through the gauge sender hole.

The third best is to rig your own little circulating polishing system and about buy about 150 filter cartridges.

Carl

[Cheechako]

If you have the tanks flushed and polished, hopefully they can access the tank inspection ports to do a good job. Also, beware if you bought a boat with one tank empty. I bought one that way and discovered a big leak when I filled the tank the first time! You tanks could be anything from steel, SS, Aluminum to monel. Of those, Steel will be magnetic. SS might be magnetic, might not.

[Fueldiva]

Originally Posted by Cheechako

If you have the tanks flushed and polished, hopefully they can access the tank inspection ports to do a good job. Also, beware if you bought a boat with one tank empty. I bought one that way and discovered a big leak when I filled the tank the first time! You tanks could be anything from steel, SS, Aluminum to monel. Of those, Steel will be magnetic. SS might be magnetic, might not.

Fuel Tanks are usually steel of some kind. Not usually Monel on a production boat.

Your problem sounds like it is bug growth.

The best way to deal with it is to have your tanks cleaned and for about twice that you can deal with the problem permanently and have a polishing system designed and installed.

The empty tank is a bit of a red flag. Check your bilge for signs of fuel leakage. Brown stains, smells etc.

A good polishing company should be able to determine if there is a leak in the tank. If you test it with water you will create a problem of waste.

One way to test it is to plug off all the outlets and introduce an inert gas with a gauge and see if it holds pressure for 8 hours.

You cannot use air as that creates a bomb.

Again a fuel polishing company worth its salt can help you there.

Caution! A tank is never really empty as the fuel pick up is above the bottom of the tank. A fuel polishing company will be able to empty the tanks before pressure testing

Nice looking boat and well worth the effort!

[sdowney717]

got to have an inspection clean out port.
If not may be you can make one.
Get in there and scrape it out.
When you get the inside clean then perhaps setup a pump and some cartridge filters. Put the pump in the middle, filters on the end.
An exposed cartridge filter you can clean the yuck off whereas a spin on can you cant.
put in some diesel and let the pumps runs. IF the cartridge clogs put in a second set. Take the first set and rinse them out with a garden hose. Let them dry and re use them over and over till it is clean..

[Cheechako]

I thought Hydrogen was explosive? Argon maybe....

[Pete7]

Originally Posted by Cheechako

I thought Hydrogen was explosive? Argon maybe....

Is heavier than air, not sure how you get a couple of hundred litres out of the bilges when the tanks are topped up afterwards. Can't think the diesels will be thrilled about running on the stuff.

Used to pay 1p per litre for Argon as a diving gas, but its probably gone up a bit since

Pete

[Capt Allan]

I want to thank you all that responded to my query about my fuel tanks. I am now on my boat and have checked the tanks and they are steel 250 gal size. Evidently the original 1980 equipment was the steel tanks.

[Charlie]

The only way to do the job properly is to cut in access ports and clean the tanks with a scraper, scotch brite pads, and some sort of cleaner ( I used Windex). I have these on my boat and am a satisfied customer ( no financial interest) Seabuilt - Access Plate Systems Alternatives to this are fuel polishing, I did this to my boat and it didn't work out well, a polishing system, and/or a day tank. Where you install a new tank and pump fuel thru a filter into the new tank for use. By far the best IMHO is to cut access ports and clean the tanks. I have done this on three different tanks and each time have pulled out a load of crap that would clog the filters after the diesel had been agitated by rough waters. Here is a link to a 20 year old tank that had been polished. https://picasaweb.google.com/1100267...NDps4Gl1ZeflwE

[DeepFrz]

+1 on Charlies post. I want to emphasize that you must get inside and clean those tanks. A steam cleaning system will work if you have access to all segments of the tank. I have had to mess with a clogged fuel line in a seaway and it is no fun whatsoever. In the wrong place at the right time it could kill you.

[ATC]

Recent customer had a fourty year old 42' Grand Banks that had the tanks replaced years ago. The new tanks 1/4" thick alumimum, (4) 200 gallons, two port and two stb'd were stacked, one on top of the other. The micro-bio growth was resting in the lower two tanks. No access to these tanks for proper cleaning, so we cut two holes, one forward and one aft. Drilled and tapped for bolt attachment to be installed later. Then we started our cleaning, once done we installed our gasket material and plates. Bolted up and returned the fuel that had to be removed during this procedure.

All four tanks were not cleaned, only the two lower ones for that being the lowest point. If your tanks are steel, use caution and check for rust deposits.

[mbianka]

Originally Posted by DeepFrz

+1 on Charlies post. I want to emphasize that you must get inside and clean those tanks. A steam cleaning system will work if you have access to all segments of the tank. I have had to mess with a clogged fuel line in a seaway and it is no fun whatsoever. In the wrong place at the right time it could kill you.

Agree with DeepFrz and Charlie. Like Charlie's photos show I found similar tar like formations when I opened up my fuel tank:
THE BIANKA LOG BLOG: IN THE TANK: Part One, Scene of the grime!
IMO fuel polishing may be a waste of money. I think the money would be better spent in putting inspection ports in the tanks so you can inspect and clean them yourself.

[Capt Allan]

Unfortunatly no inspection port on my steel tanks that I can find. Talked with a well know tank builder here and as long as the tanks are not leaking, which they are not, he has recommended trying the fuel treatment idea first. Also if I can get a vacumm line down the fill hole, or pick-up hole, to run that around the inside as much as possible after pumping out thru a filter the remaining fuel in the tank, estimated to be about 61 gal. I can pump that into the other tank that has the space. Then I can reverse the procedure, that way getting both tanks.
Most of the problem seems to be more gel like substance than anything. As far as any flaking metal may be concerned I can try running a flexible magnet down into the pick-up hole and see what I get. This may be all a waste of time but will be far less costly than the $3300 new tank that was given. That would be x 2. It may come to that but I am not ready to do it yet.
Appreciate all your information as it is all helpful.