CH3CH2OH

I'm assembling a Wild Hare 35% extra(very nice plane!), and trying to keep the overall weight to 23 to 24 lbs. I noticed the dubro tank that comes with it is tough and durable, but weighs almost half a pound! This has lead to a search for a lightweight gastank, but to no avail. Is there such a thing?

Tired Old Man

My Feedback: (1)

You can only get so light. Eventually you reach a point of diminishing returns in weight versus cost.

In the size tank you're using most are close to the same overall weight. Bite the bullet with the tank and shave what you can elsewhere. You're largest single weight component is the engine. You can save a little in prop and spinner selection by using a wood instead of carbon prop, and a fiberglass instead of aluminum spinner. Those two items alone will pick up half a pound or more.

CH3CH2OH

Thanks Pat, as always your advice is revered.

outssider

My Feedback: (23)

hayes tanks are light...but don't know if they make one big enough for ya !!

yarom

My Feedback: (82)

If anything, at that size, I am looking for a better tank. I replaced the DuBRo with a B&B tank.

The saving on a 35% can very get significant elsewhere. A light wing tube, lighter wheels or gear, can raduce much more than you would save with a thinner gas tank...

weg

Hi;
Try to use 1 liter coca cola bottle.
It is very light and gasoline resistance.

Regards

Mariusz

CH3CH2OH

Funny, thats exactly what I was looking at and thinking this might work great and save 3 oz. I guess great minds think alike.

Torqued-Up

My Feedback: (16)

Yep... 1 liter = 32oz... roughly... Perfect for a 35% airplane...

pe reivers

Just my idea. The modern polyprop bottles are just the ticket for airplanes. It don't get any lighter than that, or they would've done it. Finally a mass produced item that suits our needs.
All you need is gas nipple and klunk set. Not even a special stopper is required!

pe reivers

Hi Pat,

JoeAirPort

My Feedback: (41)

Not only that butt they are tuff. I've dropped full 2-liters and they don't break (but they do bounce ).

Here's one issue: the shape, how do you anchor them down without them rolling?

CH3CH2OH

I think zip ties and a little foam under the bottle should do the trick. It shouldn't matter if vibration makes the bottle roll if the vent, main, and fill are through the cap, but then again i usually get it right on the third try.[sm=spinnyeyes.gif]

altavillan

My Feedback: (1)

I would think that by the time you built a cradle to secrure the round bottle it would cost you more weight than a flat sided tank.

CH3CH2OH

Altavillan, I think your right. The b&b tank is 1 oz lighter than the dubro and I will settle for that, but it's a fun challange trying to come up with a lighter tank. Pat is right as usual.

flatlandmike

My Feedback: (17)

Why Ethanol?

CH3CH2OH

FLATLANDMIKE, I will do both and see how much weight I can save. This kind of project cost very little so why not. I'll bet if we could make a tank that weighed half the normal tank it would become a standard in large scale.

sensei

I have been using a 1 liter plastic bottle now for almost a year, weight is around 3 ozs. ready to install.

Bob

CH3CH2OH

love it!!

Evenbigger D

My Feedback: (1)

Where do you get the fittings for the pop bottle?

Paul Cataldo

My Feedback: (10)

Hey sensei,
I am interested to hear how you sealed the top screw on cap? Did you use some type of sealant, teflon tape, or did you just screw it on?
How about that black stuff just behind the white bottle cap? What is it?
Finally, is that a red ano'd SWB aluminum fuel tank cap that you somehow retrofitted to the bottle cap???

Tired Old Man

My Feedback: (1)

Nice idea.

Ya know what weighs a lot less than a hundred zip ties? Dental floss. If you're going to bundle wires that tight all those ties add up after awhile. Tie them up with dental floss. More time and effort but less weight.

greyhound man

My Feedback: (5)

One of the guys I fly with put a kevlar tank in his 40% Carden 260 It is extremely light weight but cost was prohibitive I believe it was $100+. It is actually intended for use in jets which is probably the main reason it costs so much.

flatlandmike

My Feedback: (17)

No I meant why is your screen name the atomic structure of Ethanol. It's a very interesting choice.

Im all for what saves weight. I like the bottle idea. There are composite material tanks made for jets that a person on the giants used to save 5 or more oz.. I do a lot of things to save weight ands some of those are use less tie wraps less Velcro and so on.


Edit: i didnt see some of these posts with the info of the jet tank already, sorry Greyhound

sensei

[quote]ORIGINAL: Paul Cataldo



Hey sensei,
I am interested to hear how you sealed the top screw on cap? Did you use some type of sealant, teflon tape, or did you just screw it on?
How about that black stuff just behind the white bottle cap? What is it?
Finally, is that a red ano'd SWB aluminum fuel tank cap that you somehow retrofitted to the bottle cap???

[/quote

The red cap is a Sullivan cap & stopper set I bought at the LHS, and the Black stuff is actually PRC tank sealer however you can purchase Permitex sealer from your local automotive store and get the same results. The Kevlar tanks are nice but even after all that money they are still heavier than the plastic Coke bottle.

Bob

sensei

That is a great idea Pay Roy.

Bob