Aluminum gas tank

[rlmankins 1]

Has anyone thought about moving the gas tank to behind the seat using a facet pump and eliminating the fiberglass wing tanks. Would be pretty easy to weld up a custom aluminum fuel cell to fit there, I believe you could change out the rod for cables, rod looks like a prob anyway under the seat, to make room for it. Not sure about cg but should be close. Not to happy about sitting on gas but not looking forward to gas tanks leaking either. I am sure this has been beat to death as a topic but can not find in search. Feel free to flame me, only dumb question is one not asked.

Thanks

Roy

[EDMO 1078]

Has anyone thought about moving the gas tank to behind the seat using a facet pump and eliminating the fiberglass wing tanks. Would be pretty easy to weld up a custom aluminum fuel cell to fit there, I believe you could change out the rod for cables, rod looks like a prob anyway under the seat, to make room for it. Not sure about cg but should be close. Not to happy about sitting on gas but not looking forward to gas tanks leaking either. I am sure this has been beat to death as a topic but can not find in search. Feel free to flame me, only dumb question is one not asked.

Thanks

Roy

I am sure you will get some better answers on this - My Kitfox 1 & 2 with the 2 cycle engines had the 6 gallon tank behind the instrument panel - another 6 gallon tank behind seat might be feasable, but dont think any larger would do.

ED in MO

If you are going to pay for an aluminum tank - Why not an aluminum wing tank, or one of the newer FG alcohol-proof tanks, or the plastic tanks?

Edited 4 Feb 2013 by Ed In Missouri

[1avidflyer 1983]

I am sure you will get some better answers on this - My Kitfox 1 & 2 with the 2 cycle engines had the 6 gallon tank behind the instrument panel - another 6 gallon tank behind seat might be feasable, but dont think any larger would do.

ED in MO

If you are going to pay for an aluminum tank - Why not an aluminum wing tank, or one of the newer FG alcohol-proof tanks, or the plastic tanks?

Kitfoxes and Avids both used aluminum wing tanks for a while, had problems with leaks developing. I think it may be from the flex in the wings that caused the tanks to start leaking. I think most of the people who have had problems with fiberglass wing tanks were the people who were using fuel with alcohol in it. I think the lastest fiberglass tanks use a fiberglass resin that is less effected by the alcohol. Take care, Jim Chuk

[rlmankins 1]

Kitfoxes and Avids both used aluminum wing tanks for a while, had problems with leaks developing. I think it may be from the flex in the wings that caused the tanks to start leaking. I think most of the people who have had problems with fiberglass wing tanks were the people who were using fuel with alcohol in it. I think the lastest fiberglass tanks use a fiberglass resin that is less effected by the alcohol. Take care, Jim Chuk

I live in the country and only have acces to ethanol blended fuel. Can I open my tanks and add a layer of ethanol resistant glass to my existing tank?

[akflyer 1427]

I live in the country and only have acces to ethanol blended fuel. Can I open my tanks and add a layer of ethanol resistant glass to my existing tank?

There are several things you can do that seem to help out. 1. if you mix a little 2 stroke oil in the gas it seems to be doing something to the moonshine and it really lessens the attack on the older tanks. 2. empty your tanks after every flight. The guys that are doing this are not having any issues with the moonshine in the tanks. Make sure your fuel lines are rated for corn poo.. 3. Buy new tanks from kitfox. The tanks will work in an avid, but you make have to do a very little bit of fairing on the cap strips to make them match the rib profile. The difference is so subtle that when you are done, no one would ever know there was a KT tank in your wing. 4. You can drop in the plastic tanks from wing tanks.com.

I would not want to put a 28 gallon fuel cell behind the seat. You WILL have CG issues. If you are just talking about enough for a 2 hr local flight it may be OK but I would not want too large of a tank back there.

[rlmankins 1]

There are several things you can do that seem to help out. 1. if you mix a little 2 stroke oil in the gas it seems to be doing something to the moonshine and it really lessens the attack on the older tanks. 2. empty your tanks after every flight. The guys that are doing this are not having any issues with the moonshine in the tanks. Make sure your fuel lines are rated for corn poo.. 3. Buy new tanks from kitfox. The tanks will work in an avid, but you make have to do a very little bit of fairing on the cap strips to make them match the rib profile. The difference is so subtle that when you are done, no one would ever know there was a KT tank in your wing. 4. You can drop in the plastic tanks from wing tanks.com.

I would not want to put a 28 gallon fuel cell behind the seat. You WILL have CG issues. If you are just talking about enough for a 2 hr local flight it may be OK but I would not want too large of a tank back there.

:BC:/>

What I was thinking of doing was to put about a 12 gallon tank behind the seat for local flights, leave the 14 gal in the wing. I can buy av fuel in Las Vegas, put it in the wing for safety, fly with the blended in the aluminum tank around town and on trips use av fuel. Does this seem reasonable?

[Guest]

What I was thinking of doing was to put about a 12 gallon tank behind the seat for local flights, leave the 14 gal in the wing. I can buy av fuel in Las Vegas, put it in the wing for safety, fly with the blended in the aluminum tank around town and on trips use av fuel. Does this seem reasonable?

In my mind's eye what you are talking about seems very reasonable especially in light of most of our planes being very much at the forward end of the CG bracket most of the time we fly them (unless we are camping).

That said, the CG would be changing as fuel is consumed (unlike fuel in the wings which doesn't change CG too much), and you would have to watch it when going camping that you don't start out too far aft CG. If there is a way to conform the tank to a taller form factor and tried to keep the mass of the fuel as far forward as possible, it would have the least effect on CG as fuel were added or used up.

Just random thoughts.

Chris

[Guest]

Has anyone thought about moving the gas tank to behind the seat using a facet pump and eliminating the fiberglass wing tanks. Would be pretty easy to weld up a custom aluminum fuel cell to fit there, I believe you could change out the rod for cables, rod looks like a prob anyway under the seat, to make room for it. Not sure about cg but should be close. Not to happy about sitting on gas but not looking forward to gas tanks leaking either. I am sure this has been beat to death as a topic but can not find in search. Feel free to flame me, only dumb question is one not asked.

Thanks

Roy

A second thought. I would try to do the fuel tank directly behind the seat in front of the mixer and not remove any of the control rods. A couple of my friends have greatly increased the storage space in their Avids by building compartments directly underneath where the cloth storage bag goes behind your head (if you are familiar with that). There is a fair amount of volume they have been able to gain for camping storage this way. I do not know how many gallons of fuel this would represent but it is not a small amount of space.

The reason why I would not go away from the rod linkages is they are very well known, work well, are very reliable and can be 100% inspected any time you want or need to. I just bought an Avid Plus with push pull cables and they make me nervous. I've already ordered new cables so I will be starting from scratch with new ones the first time I fly it. I am trying to figure out how often in terms of time/flight hours I will replace them too. There is no way to inspect push pull cables to know if you are approaching the flex life as far as I know. I know if my Avid Plus had rods and bellcranks, I would not be considering switching to push pull cables! Open cables like on the highlander are a different and completely acceptable alternative, but I do not know what you are referring to.

ChrisB

[EDMO 1078]

Roy,

Before trying to put a tank behind the seat, which can cause balance problems, I would slosh my fg wingtanks with CASWELL. This epoxy is used on motorcycle tanks with good results. Cost about $40 a tank.

Or, you could buy the new tanks, or inserts.

We have had lots of pro and con discussions on here about it.

I dont know your location, but they supply non-alcohol gas to farmers and boats - got a Marina nearby?

ED in MO

Edited 5 Feb 2013 by Ed In Missouri

[rlmankins 1]

A second thought. I would try to do the fuel tank directly behind the seat in front of the mixer and not remove any of the control rods. A couple of my friends have greatly increased the storage space in their Avids by building compartments directly underneath where the cloth storage bag goes behind your head (if you are familiar with that). There is a fair amount of volume they have been able to gain for camping storage this way. I do not know how many gallons of fuel this would represent but it is not a small amount of space.

The reason why I would not go away from the rod linkages is they are very well known, work well, are very reliable and can be 100% inspected any time you want or need to. I just bought an Avid Plus with push pull cables and they make me nervous. I've already ordered new cables so I will be starting from scratch with new ones the first time I fly it. I am trying to figure out how often in terms of time/flight hours I will replace them too. There is no way to inspect push pull cables to know if you are approaching the flex life as far as I know. I know if my Avid Plus had rods and bellcranks, I would not be considering switching to push pull cables! Open cables like on the highlander are a different and completely acceptable alternative, but I do not know what you are referring to.

ChrisB

That seems entirely reasonable. I just found out the FAA is mandating inspection of the control cables on my Cherokee yearly. I have been doing it anyway, major pain but it is my a!! If it fails. Tank can be built in any configuration and that seems very doable. I want to keep it as close as possible to the front so that should work. I think the biggest issue is to keep the volume to a reasonable level, looks like it could hold a lot. Since I only have a 14 gallon tank I need the extra capacity anyway. In avids with higher capacity is there fuel in both wings? Might be easier just to munt the tanks in the other wing.

[EDMO 1078]

That seems entirely reasonable. I just found out the FAA is mandating inspection of the control cables on my Cherokee yearly. I have been doing it anyway, major pain but it is my a!! If it fails. Tank can be built in any configuration and that seems very doable. I want to keep it as close as possible to the front so that should work. I think the biggest issue is to keep the volume to a reasonable level, looks like it could hold a lot. Since I only have a 14 gallon tank I need the extra capacity anyway. In avids with higher capacity is there fuel in both wings? Might be easier just to munt the tanks in the other wing.

Why not just buy the newer FG or plastic tank for the other wing. I dont like gas on my ass!

ED in MO

Edited 5 Feb 2013 by Ed In Missouri

[rlmankins 1]

Why not just buy the newer FG or plastic tank for the other wing. I dont like gas on my ass!

ED in MO

I have to quit complicating things, I assume that everyone has tanks in both wings. Since I only have tanks in one wing how would I mount the poly tanks in the other wing. I guess I would have to put a rigid support structure in place.

Any suggestions?

[EDMO 1078]

I have to quit complicating things, I assume that everyone has tanks in both wings. Since I only have tanks in one wing how would I mount the poly tanks in the other wing. I guess I would have to put a rigid support structure in place.

Any suggestions?

Dont know about Poly tanks, but imagine they are the same as the alcohol-proof FG tanks that Kitfox now has - The FG tanks just nestle between the spars, and can be held in place with GE Silicone II - That is what Kitfox says - They even say to wrap the spar with saran-wrap before siliconing to make later removal easier, although I did not do that. Some use strapping tape along with the silicone.

Nothing else is required for mounting the tanks, except a one gallon header tank just behind the seat which is fed by both wingtanks and has a vent line going to one of the wing tanks.

I put a ribcap down the center of my tanks to prevent ballooning of the fabric - some use solid plywood over the tanks - anything is optional.

ED in MO