Fuel tanks with clear ends

[neil_1821]

Looking at a variety of models, YouTube, google image search I always seem to find fuel tanks that have visible ends, quite useful to see how much fuel you have left!

Can anyone enlighten me as to how they are built?! I’d assume it’s glass rather than Perspex giving that it holds fuel, but how are they sealed as to not leak? O rings, gasket, interference fit?

 

[R Degen]

You have to use lexan and I use an oring to seal it with a press fit. Randy

 

[rickhann]

I have used old watch crystals for small tanks. It's been a while, but I think I just turned a brass ring too fit the crystal and epoxied the crystal in. Been several years with no leaks.
rick

 

[cheepo45]

I used a watch crystal from Amazon glued into a recess on the brass tank end with gorilla super glue.
It has been almost a year and a lot of hours running and it's still holding up fine - no leaks. I'm running Coleman fuel with a little WD-40.

 

[neil_1821]

Ah yes that’s lovely, I’m intending to use Coleman’s fuel. You can’t even see the superglue, very nice. I’ll have to try making one soon.

 

[Engine maker]

Yep, way back when, I was looking for some way to put a small neat fuel gauge on a tank, then it dawned on me to make the whole tank a gauge. I have a problem with filling the tanks. I always try to get 2 1/2 oz. of fuel in a 2 oz. tank and as many times as I've tried it, it still doesn't fit!

FYI the glass is flat mineral glass watch crystals, (Plexiglas crazes after a while). Cost about $ 9.50 for a set of 3. You can get it any dia. (goes up by .004" or .1mm sizes) and thickness - 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm. The 3.0mm thickness equals .120" so if you make a 1/16" recess in the tank flanges and one in the fuel tank side you can put a nice thin "O" ring inside for a seal. Never had one leak yet! I get mine here www.ofrei.com/page1190.html
Be careful it is a large site and easy to get lost.

Jim G

 

[el gringo]

another way...
I cut lexan rod in half along the centerline and epoxy it to a slot in the fuel tank, kinda vertical sight glass.

 

[Longboy]

You can look at Ebay and order clear round carbochons. I use clear 5 minute epoxy in brass.