Gas tanks again

[birddog486 21]

Does anyone know if the kitfox 13 gallon model 1 2 and 3 wingtanks will fit in the Avid flyer speedwing?

 

 

Travis

 

[EDMO 1078]

Travis,

     Doug Holly is probably the best source for that info, but he is in Osh - and so is Brett???

I posted the Kitfox 1-3 ribs in combo with KF 4 ribs - maybe if you could print it and enlarge it to size, and lay a speedwing rib on top of it, it might answer your question.

EDMO

[birddog486 21]

I'm not concerned about the tank shape so much as I'm wondering if the tank will fit between the spars. I raised my turtledeck so the speedwing and the undercambered profile doesn't match anyways. The picture above is what 91 octane ethanol free gas does to the Stewarts systems Primer coats.

 

Travis

[EDMO 1078]

My tanks are about 32 inches wide - I can measure them tomorrow.   The Spars on all Kitfox and avid are on the same center distances, so they should fit the spars - I don't remember what that distance is - I think it is 27 1/2 - can measure that tomorrow.

EDMO

[birddog486 21]

Those measurements would be great Ed.

[EDMO 1078]

Travis - that looks like the leading edge - got to know how gas got there instead of trailing edge or somewhere else.  Also, got to warn my J3 buddy about this.

EdMO

[birddog486 21]

Ed, the wing was folded and had 7 gallons of gas in it (16+ gallon speedwing tank). It looks like the leak started at the top rear outside corner of the tank because, there is a small area of bubbled paint on the top of the wing there. It ran down along the ribs and down the front spar all the way to the wingtip light lifting the primer as it went.

 

I talked to Doug Stewart about it and he wanted me to get some air blowing inside the wing to get it dried out as fast as possible. He said to give it a few days because he's seen the paint lay back down once the gas is out but im not holding my breath with this much damage. He said worst case looks like I'll have to peel and sand a bunch and reprime and paint all the damaged areas. Mr. Stewart didn't see a need to pull the fabric but I'm thinking if there are several areas that need repair and I'm going to open the wing to replace the tank I may just pull all the fabric but time will tell.

 

Travis

 

Edited 1 Aug 2014 by birddog486

[EDMO 1078]

Travis,

     Thanks for the explan - sorry this happened - give me a report about the paint responding to drying - or not.   This is one of my biggest fears with these glass tanks.

     I have an extra Kitfox 1 tank, and 2 1/2 wings to measure today and will post the findings.   I believe that the distance between spars is a standard 25 inches, and the tank should be slightly shorter than that.  Kitfox says to put the curved end of the tank against one spar - I forget, but think it is the front - and drop the other end into place from the top side, secure with strapping tape,and seal with GE Silicone II caulk underneath and inbetween on both spars.  Oh yes, before doing that, they say to wrap your spars with plastic wrap (Saran wrap) for easier removal of tank later on - (I forgot to do that when I sealed mine).

Will get back to you today and maybe a photo too.

EDMO

[akflyer 1427]

Yes they should fit, YIKES!  One more reason for me to not ever use stewarts!  I fuel from 5 gallon jugs exclusively and sometimes it gets a little sloppy when the nozzle pops out etc.. No wrinkles in the Stits paints.

 

Just making sure, but is there any way that it could have come out of the filler neck or vent?

 

[EDMO 1078]

It may be that coming from the inside is more harmful than a little spill on the outside of the urethane paint - looks like the primer was the weak part.

Travis,  Is there a possibility of just cutting a hole where the leak is and repairing it?  If it is a pinhole, maybe drill and put some epoxy to close it?

EDMO

I measured two different wings - distance between spars is 25 inches.

Tank measures somewhere between 24 3/4 and 24 7/8 at narrowest place.

Posting 2 photos, I hope.  You can see that the curved part is in the front - You drop this onto the spar first.

Disregard the ridges you see on the front curve next to the tape measure - that is old caulk.

ED 

Edited 1 Aug 2014 by Ed In Missouri

[birddog486 21]

Thanks Guys. This wasn't caused by any gas coming from the cap. I wish I could have been that lucky. The paint is pretty tough and seems to resist any staining from gas, Its the primer that is causing the problem from the inside. The paint is very flexible and its just streching as the primer swells. I've got a small fan blowing through the wing but as of now it's not looking good.

 

The Avid wing is built without a rib to the inboard side of the tank, The tank itself butts up to the butt rib. How wide are the Kitfox tanks between the ribs?

 

Ed, I cut the tops out of these tanks and reseald them with vinyl ester resin before I put them in the wings. Obviously these early tanks were not a quality product and just trying to bandaid them bit me. I should have bit the bullet and bought the newer Kitfox tanks at that time so I would have only had to cover and paint the wings once.

 

The stewarts said that AV gas will not do this to the primer, only car gas and It doesn't matter if its ethanol free. I've been really carefull to test the gas for ethanol and theres been none in these tanks.

 

 

Travis

Edited 1 Aug 2014 by birddog486

[EDMO 1078]

The body of my tank is 31 3/4 across, and the lip on top is 34 - no lip on bottom. 

distance between ribcaps is about 34 1/2. 

You may have to add a root rib.  If you add a root rib, then you need to put 4 or more wood braces epoxied between root rib and gas tank to keep fabric from bending root rib.  I used short, about 3/4 diameter, wood dowels.  Kitfox says to wait until your wing is assembled to the fuselage before locating the root rib against the butt rib.

Hope this helps.

EDMO

     I wonder if it would work to coat the OUTSIDE of the tank with vinylester???

Edited 1 Aug 2014 by Ed In Missouri