Aluminium fuel tank?

[Tomo]

My fuel tank in my Solitaire is weeping... it is made out of fibre glass, slightly agriculturally if you ask me, but I guess it worked. But now, I think it's time to upgrade a fraction and make things a little safer. And more ergonomic...

 

I'm thinking of making a new tank out of aluminium, but just wanted to hear what others thought of that material? Or should I just make another out of glass? Personally I'd rather use alloy because I know more about welding that stuff than fibre glass building!

 

Thoughts?

 

 

[damkia]

Try some auto racing fuel cells similar to this http://www.gmpracingproducts.com.au/fuel-cells/fuel-cell-bladder-fill-plate-sportsman.php

 

 

[turboplanner]

It's probably only weeping because of the flogging it's had over the past few months - it never gets a rest.

 

 

[skyfox1]

My fuel tank in my Solitaire is weeping... it is made out of fibre glass, slightly agriculturally if you ask me, but I guess it worked. But now, I think it's time to upgrade a fraction and make things a little safer. And more ergonomic...I'm thinking of making a new tank out of aluminium, but just wanted to hear what others thought of that material? Or should I just make another out of glass? Personally I'd rather use alloy because I know more about welding that stuff than fibre glass building!

 

Thoughts?

Hi Tomo make a new one out of aluminium you wont regret it l have made a few over the years they work great,get it pressure tested mount it right wont have a problem ..

cheers Geoff.

 

 

[Compulsion]

Tomo check Gareths tanks he has put on his Sierra he is building. I think check under Sierra 100.

 

 

[Guernsey]

Fibreglass is a problem if you accidentally use fuel with Ethanol added.

 

Alan.

 

 

[rgmwa]

The RV-12 that I'm building has a riveted aluminium tank (2024-T). It's basically a rectangular box, and is pop riveted with aircraft grade blind rivets. Joints are sealed with Pro-seal. Here's a link to the current tank plans on Vans website that may be useful. http://www.vansaircraft.com/public/archived12.htm Section 37 is the one you want. Your situation will obviously be different, but the plans should be helpful.

 

rgmwa

 

 

[Guest Andys@coffs]

Fibreglass is a problem if you accidentally use fuel with Ethanol added.Alan.

Alan

Is it the fibreglass thats the problem or the sloshing sealant? Im pretty sure Ive always read that ethonol is a problem with particular sealants not so much the flbreglass itself.... But I guess to a certain extent its mute, Al tanks probably dont need a sloshing sealant...... (ED unless you use blind rivets as above )

 

Andy

 

 

[rgmwa]

AlanAl tanks probably dont need a sloshing sealant...... (ED unless you use blind rivets as above )

Andy

It's not a sloshing sealant Andy. It's a 2-pack polysulphide used to seal the lapped seams, internal corners and tank fittings. Vans use sealed and riveted tanks (blind rivets on the RV-12, and driven rivets on the others) for all the RV's, and have actively discouraged the use of sloshing sealants since the early 1990's.

 

rgmwa

 

 

[Riley]

Tomo

 

Assuming you go with the alloy tank it's worthwhile (even tho it's a pretty compact vessel) to consider incorporating a baffle to preclude both surging and sidewall drumming. I had no end of hell in the progressive 'rat-killing' of weld cracks in the Hummelbird tank as they appeared due to vibration. Think I had the tank out on 4 occasions before the problems were resolved by going to solid rivetted, 'Pro-sealed' flanged tank-ends. Also IMO, tho it's a fine remedy for rusted vintage car fuel tanks, I'd stay well away from any 'Slosh' type internal coatings if you possibly can. cheers

 

 

[pylon500]

Alloy tanks are OK once you get past the time it takes to make them.

 

There are differences in alloy tanks, welded or riveted.

 

I've had a welded tank that ended up with porous welds

 

Riveted tanks need to be sealed around the edges with 'Pro-Seal' which is a horrible and messy stuff, (used it all the time in the RAAF)

 

Avoid sloshing compounds, they break down with ethanol and two stroke oil!

 

Riveted tanks can be a bit easier if you can arrange to have the rivets through external flanges, still pays to have an access hole somewhere though.

 

Arthur.

 

ps, Hows that prop going?

 

 

[Tomo]

Thanks for the help guys, will look into a few different ways and see how it goes!

 

Arthur, I haven't had a real good test of it yet, but done about 15 minutes in the air with it and it goes pretty well, though I will like to pitch it up a bit more as it will rev out a bit much, climb out is improved dramatically though. And so much smoother it's not funny. My tank was starting to leak so decided I won't fly it till I fix that.

 

 

[pylon500]

You may get away with trying to repair the glass tank, the hard bit is removing ALL traces of the two stroke oil to get the resin to stick.

 

Try repeated flushing with neat petrol, probably half a litre a time followed by a couple of flushes with acetone or MEK if you can find it.

 

A.

 

 

[damkia]

Would it be possible to get a bladder made to suit the old tank? Seems to me that this could be a good alternative to trying to repair the contaminated fiberglass.

 

 

[Guest Maj Millard]

Tomo, The Lightwing has welded alum tanks, as do many otherw of course.The welds can be porous as pylon said, so you need to pressurise and leak check. Leak areas can be rewelded, or covered with Proseal. You can weld on tabs for mounting, and 1/4" plate externally, which can be drilled and tapped for threaded fittings. The internal baffles are a good idea..................................................Maj...

 

 

[kgwilson]

There's nothing wrong with fibreglass so long as you use vinyl ester as it is very chemical resistant. Easy to mould to any shape & install baffles. Cut the old one in half to use as a mould.

 

 

[Old Koreelah]

There's nothing wrong with fibreglass so long as you use vinyl ester as it is very chemical resistant. Easy to mould to any shape & install baffles. Cut the old one in half to use as a mould.

Totally support this. My vinyl ester tanks are OK after about 5 years of containg all different fuels. Consider moulding tanks inside a cardboard or plywood box. Fill all corners with gently-curving plasticine to reduce the risk of ruptures.

 

 

[turboplanner]

You may get away with trying to repair the glass tank, the hard bit is removing ALL traces of the two stroke oil to get the resin to stick.Try repeated flushing with neat petrol, probably half a litre a time followed by a couple of flushes with acetone or MEK if you can find it.

A.

The problem here is capillary action along the glass fibres. You can get a bond, but it skips over these, providing areas for fuel to leak.

 

 

[facthunter]

I wouldn't go near MEK. It'll give you cancer.

 

I reckon a welded Al sheet tank is the go. If you are doing a good weld in new metal you can virtually guarantee a seal. (Pressure test it anyhow) I don't condsider myself an expert , but the mount points need extra attention or you will get fatigue cracks eventually. If the structure flexes that the tank is mounted to, take that into acount in your design. ie 3 mount points instead of 4. I would consider some baffles essential as the sloshing fuel can put high loads on the tank. If a panel is nearly flat consider forming a reinforcing groove in it to stop oil canning. Shape it so as to be able to drain any water out easily. Try to make it easily removed. Nev

 

 

[damkia]

The trick with mounting is to either rubber isolate the mounting points, or to only use 3 mount points on the tank, preferably both methods. Don't forget an earthing strap to the battery/engine to dissipate any static, and to have a point available on the tank to connect a ground based earth point to for refueling.

 

You can purchase slosh tanks from fuel cell manufacturers that will assist in keeping fuel available at all times to the fuel pump. Consider a secondary 2-5 litre non-vented tank in line to act as a reserve to the slosh tank (all standard practice in the automotive racing world)

 

 

[Guest Maj Millard]

MEK..methyl Ethel Keytone strangly enough was all we used to cleaned the delicate nylon fabric of ejection seat parachutes with. If they didn't work, cancer was the least of your problems !!.............................................................Maj...

 

 

[winsor68]

The Skyranger kit built aircraft use a couple of plastic Jerry cans mounted behind the seats... they look to me like a fairly standard off the shelf item? Simple but is it suitable? Seemed to me from photos you could fit one of these in behind your seat.

 

 

[facthunter]

winsor I have flown one of those. They are quite a good plane with a strong frame etc. Whether 2 plastic containers in what would be the back seat is ideal( I would say NO). For a couple of reasons. In a high wing plane IF the tanks go in the wings, it is much safer in a prang and you have a gravity feed system, so that would be my preferred location. You can also build the structure a bit lighter as the fuel load is not in the fuselage. Nev

 

 

[winsor68]

winsor I have flown one of those. They are quite a good plane with a strong frame etc. Whether 2 plastic containers in what would be the back seat is ideal( I would say NO). For a couple of reasons. In a high wing plane IF the tanks go in the wings, it is much safer in a prang and you have a gravity feed system, so that would be my preferred location. You can also build the structure a bit lighter as the fuel load is not in the fuselage. Nev

From what I can gather from photo's of Tomo's machine getting the fuel into the wings would involve some major work...

 

I saw a Sapphire (very similar to Tomo's Solitaire) at Temora develop a fuel problem thankfully while on the ground... This one had the original fibre glass fuel tank behind and making up the back of the seat develop a leak and flood the cockpit and seat pan. It is ironic that I mentioned to Tomo to be wary of this with his machine if it had the same setup... Fortunately his tank is a separate structure to the seat.

 

 

[Pilot Pete]

What about a plastic tank. There are a few different types on the market or get one made in Toowoomba. Light, ding resistannt, easily repaired, chemicle proof.