Diesel Fuel Tank Replacement Advice

[davil]

thank you chrisr

like to replace mine,will follow your progress

take care
David

[davil]

Originally Posted by Celestialsailor

These are the gauges that I have been using when I build my aluminum tanks. I weld an 1-1/2" female bung in the top of the tank and thread it in. They come in various lengths.

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did you wire it to 12 volts?

my gauge is like yours, mounted on the tank that is installed under the port settee and to read while fueling need to go below and lift the cushion, is highly inconvenient, like to upgrade and extend the wiring to a remote unit perhaps in the cockpit somewhere

[Emmalina]

This is an epoxy tank I built after my steel one leaked due to corrosion (after 40years) Holds 420 liters and is a lot lighter than the steel one ! Uses a sighting tube.

[GILow]

Originally Posted by Emmalina

This is an epoxy tank I built after my steel one leaked due to corrosion (after 40years) Holds 420 liters and is a lot lighter than the steel one ! Uses a sighting tube.

I've done the same. Labour intensive.but.you can really make use of all the available space.

[GrowleyMonster]

Originally Posted by Celestialsailor

These are the gauges that I have been using when I build my aluminum tanks. I weld an 1-1/2" female bung in the top of the tank and thread it in. They come in various lengths.

Wow I need one! Link?

[GrowleyMonster]

Originally Posted by Emmalina

This is an epoxy tank I built after my steel one leaked due to corrosion (after 40years) Holds 420 liters and is a lot lighter than the steel one ! Uses a sighting tube.

Nice. Just epoxy, no reinforcing cloth or fibers? I assume you just made a female mold and poured it in layers, rotating as needed to coat the inside of the mold? What is the final thickness, approximately? I have a fairly heavy boat with a 4-107, and only a 14 gallon tank! It would be nice to be able to custom fit the tank into the bilge. I figure I could cast polyurethane foam in the bilge for a male plug, lay up a mold around that, and melt out the foam with acetone, for a perfect custom fit.

[coopec43]

Originally Posted by Celestialsailor

These are the gauges that I have been using when I build my aluminum tanks. I weld an 1-1/2" female bung in the top of the tank and thread it in. They come in various lengths.

Someone must have surely mentioned it already (a quick check and I can't find anything) but the gauge would have to be re-calibrated?
My tanks are not uniform shape so when the gauge read 1/2 it might only be a quarter.

[Celestialsailor]

Originally Posted by davil

=============================
did you wire it to 12 volts?

my gauge is like yours, mounted on the tank that is installed under the port settee and to read while fueling need to go below and lift the cushion, is highly inconvenient, like to upgrade and extend the wiring to a remote unit perhaps in the cockpit somewhere

No electricity. Works on a float. My set up is like yours… lift a cushion and view.

[Celestialsailor]

Originally Posted by GrowleyMonster

Nice. Just epoxy, no reinforcing cloth or fibers? I assume you just made a female mold and poured it in layers, rotating as needed to coat the inside of the mold? What is the final thickness, approximately? I have a fairly heavy boat with a 4-107, and only a 14 gallon tank! It would be nice to be able to custom fit the tank into the bilge. I figure I could cast polyurethane foam in the bilge for a male plug, lay up a mold around that, and melt out the foam with acetone, for a perfect custom fit.

Go on ebay and search Rochester 8680 fuel gauge.

Originally Posted by coopec43

Someone must have surely mentioned it already (a quick check and I can't find anything) but the gauge would have to be re-calibrated?
My tanks are not uniform shape so when the gauge read 1/2 it might only be a quarter.

It works just fine. Sure it's approximate but who cares? When you're down to 1/4, get some fuel. Of course they sit an inch off the bottom (depending on the length you buy), so if it's registering, you still hasve some fuel.

[gonesail]

if you have an aluminum tank made .. they can weld threaded plugs for fuel sensors or gauges.

[coopec43]

Originally Posted by Celestialsailor

Go on ebay and search Rochester 8680 fuel gauge.

It works just fine. Sure it's approximate but who cares? When you're down to 1/4, get some fuel. Of course they sit an inch off the bottom (depending on the length you buy), so if it's registering, you still hasve some fuel.

Of course you are right - an approximate idea is quite OK. A sight glass is not going to be any better in that regard but I wonder about cost? Which would be cheaper? (Something else to check out)

[coopec43]

Originally Posted by coopec43

Of course you are right - an approximate idea is quite OK. A sight glass is not going to be any better in that regard but I wonder about cost? Which would be cheaper? (Something else to check out)

Well after one minute research this one hit my eye. It looks good but although it is brass/glass I wouldn't install it without a tap at the bottom (push button type preferred) and an air return to inside of tank. (I wonder if that is possible?)


https://www.aliexpress.com/item/1005...apt=4itemAdapt


https://campaign.aliexpress.com/wow/..._id=1084300508

[CarinaPDX]

Originally Posted by markxengineerin

Worth a watch - I'm sure there are some good plastic tanks out there,

There are, but not like those two. I can't help but wonder if they told the manufacturer that they were for diesel. When the U.S. (where Tally Ho is located) introduced fuel vapor permeability standards a little more than a decade ago welded HDPE fuel tanks were no longer available. I checked with a lot of tank vendors and they wouldn't touch making welded HDPE tanks for diesel - they didn't meet required permeability standards. I doubt that has changed.

It is easy to buy roto-molded HDPE tanks, which as I understand it have a sealing layer inside of the HDPE applied during roto-molding. But roto-molding is not affordable for custom tanks. There is quite a selection available but I have not found any that fit my requirements for a stern quarter.

Greg

[CarinaPDX]

For checking the fuel level it is hard to beat the Tank Tender (tanktender.com). I have had one on Carina for 40 years and it has never required any repairs. It is dead simple, using air pressure to measure the depth, and came with a label to fill out during the first fill that relates depth to fuel content.

For non-rectangular tanks it is possible to buy fuel level senders that can be calibrated internally to match the tank, such that the output is linear in terms of fuel left.

In the last few years it has been possible to buy converters that fit between the fuel sender and the display that will provide a linear output. Of course you can just make a table with gauge reading versus fuel quantity...

Just be aware that there are two standards for fuel sender output, one common in the U.S. and one in Europe. My Volvo-Penta requires the European standard...

Greg

[Shaneesprit]

Originally Posted by GILow

No, it’s not.

I have a 1000L of fuel (Heating oil) in a plastic outdoor tank at home, UK has 100,000s of these, most much bigger than mine, Also almost every piece of industrail portable diesel powered machinery uses a plastic tank!
never known a leak or issue from a reputable manufacturer, other than 1 custom design where fibreglass used inside and someone sealed the inside joints with Silicone sealant, while this didn’t leak it did destroy all 16 of the engines cylinder heads. In a month. (Engine was also not burning regular fuel)