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sdemeyer
06-03-2009, 09:09 PM
While flying my fox this evening I had an overpowering smell of fuel followed almost immediately by gas dripping on my arm. Once safely on the ground, I was able have a look and it appears the left fuel tank ruptured somewhere near the front and top.

The original builder installed a 13 gal tank in right wing and 6 gal tank in left. The manual says both tanks should be 13 gal so I don't know where the 6 gal tank came from.

Can these tanks be repaired? If not, where would I find a replacement 6 gal tank for my IV-1200?

In case your wondering, I have no idea what fuel the previous owner used but I only use Super Unleaded with no traces of Ethanol.

Thanks,
Scott

DesertFox4
06-03-2009, 10:14 PM
Scott, the 6 gal. tanks may be associated with the wing locker option. Many 6 gal. tanks are in service. Check with Kitfox Aircraft for a replacement if it is not repairable.

avidflyer
06-05-2009, 08:43 AM
If all fittings are okey, you might think about trying to slosh the tank with a tank sealer. If it works you are only out a little work and way less money than a new tank not to mention all the work to change the tank. Jim Chuk

sdemeyer
06-05-2009, 01:22 PM
I'm removing the fabric this evening to have a closer look and see exactly where the leak is. I found a guy making replacement drop in tanks ( http://www.wingtanks.com ) if the hole is too big to patch. Installation of drop in tank looks fairly easy.

SkyPirate
06-05-2009, 02:31 PM
I'm convinced now on this model 4 I'm looking at ,..I'm going to weld up 2 aluminum tanks ..and be done with it,..using .023 aluminum I can put 2 baffles in the tank for stiffening and to reduce sloshing both in flight and when trailered ,..leaks are not an option ,..I'll fire the welder if it leaks :)

DesertFox4
06-05-2009, 03:11 PM
Chase, aluminum tanks didn't hold up well in the Kitfox . They were sold in the early days of Denny Aerocraft Company and caused problems.:(
The Kitfox wing flexes too much for the aluminum and the welded seams have a tendency to break from that flexing. Remember that the tanks are structural and are "bonded" on leading and trailing edges to the spars. Fiberglass tanks have done much better in this application.

As far as the plastic drop in tanks, the thing that makes it look like it might work is that the original tank is left intact after the top is cut out to insert the tanks. Not sure how that affects the wing structure but it just might work. I'd want to discuss it with John McBean briefly before trying it. Best of luck on the repair.

SkyPirate
06-05-2009, 03:39 PM
thanks for the info Steve..I woulda fired that welder for sure :) ha ha
you wouldn't happen to know the thickness of the aluminum that denny used would you?
I was thinking of a rolled edge seam with an epoxy sealer similar to some auto tanks,..spot welded,..the only 100% weld would be on the fittings for fill cap vent fuel flow outlet and the seam where the piece is formed into the shape of the tank,.(the top botom front and back is one piece of matierial).and the 2 side seams rolled and crimped with epoxy and spot welded,.. or like the below picture layed out with only 2 seams

avidflyer
06-05-2009, 07:32 PM
My first B model Avid had one aluminum wing tank and a while after I sold it the buyer told me it was leaking. My latest B Avid has the aluminum tanks in both wings and when I got it the one leaked as soon as I put fuel in it, but the other one held.... for about 2 months and then it started to leak also. I ordered some gas tank sealer from KBS coatings today. Hopefully that will fix the problem. The guy I bought the plane from said he never used the wing tanks, just the 9 gallon fusaloge tank. Both planes were built about 20 years ago but had less than 200 hrs on each of them when I got them. My opinion is stay away from the aluminum if you can. 3 for 3 leaked that I've been around. Take care, Jim Chuk

SkyPirate
06-05-2009, 10:32 PM
ok you guys convinced me ..I'll use something other then aluminum..hmmmm maybe some .016 hot rolled sheet metal...it might add a lb or 2 but ,,,no worries of the fuel desolving it and it should be more resilient then aluminum,..I'll still do the rolled seams with epoxy and spot weld's

Chase

jdmcbean
06-06-2009, 08:17 AM
I found a guy making replacement drop in tanks if the hole is too big to patch. Installation of drop in tank looks fairly easy.

I would not use these tanks.. there has been not testing done !

We have replacemement tanks and they are manufactured with ethanol resistant resin.

6 or 13 gallon and for all models.

jdmcbean
06-06-2009, 08:25 AM
I'm convinced now on this model 4 I'm looking at ,..I'm going to weld up 2 aluminum tanks ..

Aluminum has been tried. Both on the Avid and in the Kitfox.. They both leaked. There are some ideas but it would mean much less fuel on board.

What we have works.. and has worked for many years. The resins we are using today are resistant to the ethanol..

Burn 100LL or at a least a mix ratio of 100LL and premium.. change the oil as recommended and use TCP.

SkyPirate
06-06-2009, 08:57 AM
good point airhawg

now that I think of it ,on my race car ..there was an outer shell made of steel or aluminum and a liner that was made from a much thinner material similar to the red gas cans,.. ..it was exposed to G loads up to 12 plus(Depending on how hard you hit the wall ,..ouch) and vibration..I never had to replace the liner in my fuel tank ..and I ran racing fuel along with 100 LL.

sdemeyer
06-07-2009, 08:01 AM
After removing the fabric, a split in the top right seam was discovered. The split was about 4 inches long.

I carefully removed the #1 rib which was easy as the bonding was failed at the front spar, installed 3 teeny rivets in the tank lip, then fiberglass over the lip using fiberglass cloth and resin.

The plane has been repainted. The top coat came right off with MEK but the bottom coat does not. Do I need to sand all the paint where a new piece of Poly-Fabric will overlap or will the glue stick to the old paint?

Scott