Are Transparent Diesel Tanks Possible?

[MicHughV]

I've seen those bladder type tanks..I believe they make them for diesel fuel as well. You have to fit the fill hose and fuel supply lines, etc, yourself in some appropriate location.

Let's not forget a diesel fuel tank also needs a fuel return line. I can't see where this would be an improvement over a sealed wood tank, especially so, when it comes to tying or bracing the thing down. At around 7 lbs per gallon....a 50 gallon would be 350 lbs flopping about in a seaway. hmmmmmm ?????

[CarinaPDX]

Ever since the US government set standards for fuel permeability a decade ago custom-welded PE tanks for fuel are no longer available in the US (at least legally). It is possible to buy them elsewhere (e.g. Tek-Tanks in the UK) or perhaps you could trick someone by telling them it is for water or something, but I recommend sticking with the legal solutions. The plastic tanks sold in stores, whether portable or fixed, are rotomolded XLPE or HDPE that are lined (with nylon I think) to provide the vapor barrier. They are available in a lot of shapes and sizes so take a look for one that fits. I doubt that making a custom mold for a custom tank shape would make any sense financially.

If the goal is to see the fuel level then I recommend buying a Tank-Tender system. It requires a #6 threaded hole on the top of the tank for a fitting that supports a thin plastic tube that extends to near the bottom of the tank. It works by pumping air until it bubbles up, looking at the pressure gauge which is calibrated in depth, then reference your table of depth vs. gallons. It is accurate and bullet-proof. Mine is 40 years old and never needed any repairs. And of course always have a clean-out port. I put a copper tube to the bottom of the tank for clean-out, but it plugged up from the remains of algae.

Greg

[Squanderbucks]

My boat has two self built fiberglass tanks that I built back in the ‘90’s. Depending on the size of tank needed the thickness will determine the degree of translucency.
If all you are satisfied with lust being able to see fuel level that should be no problem. I can see the fuel level in my tanks and they are 100 gallons each. I still have fuel senders installed so I don’t have to go below decks to know levels but for those who don’t want gauges Then the direct visual Is possible.
Also FRP allows you to build in baffles. That Toto molded tanks often lack.