Old Weeping Fuel Tanks

[DHeal]

I am considering the purchase of a friend's 15 year old RV-4. Both fuel tanks show evidence of some fuel weeping (staining only, no dripping or active wetness) - likely from the aft side of the tanks. I know that I really need to remove the tanks to see where they are leaking from.

My question is: Is it possible to effectively address these leaks by removing the tanks and using a sloshing compound, as opposed to rebuilding the tanks entirely? Any input will be appreciated.

[rvator51]

Originally Posted by DHeal

I am considering the purchase of a friend's 15 year old RV-4. Both fuel tanks show evidence of some fuel weeping (staining only, no dripping or active wetness) - likely from the aft side of the tanks. I know that I really need to remove the tanks to see where they are leaking from.

My question is: Is it possible to effectively address these leaks by removing the tanks and using a sloshing compound, as opposed to rebuilding the tanks entirely? Any input will be appreciated.

Assuming the tank is leaking from where you are thinking, my preference would be to cut access panels in the rear baffle between the ribs of the leaking area and reproseal the leaking area inside the tank. When finished, cut slightly larger panels to fit over the holes, proseal them and pop rivet them back on.

[Vern]

It has caused much trouble for those who have sloshed in the past. Do a search for 'slosh' on various lists and you can understand why.

A little Pro Seal to a few strategic leaks and you will have it solved. No need to rebuild. You may be able to access the leaks thru the end plates or if you have to, you can cut access hole(s) in the rear baffle and seal thru them.

[Mel]

If it's 15 years old, it most likely has slosh compound that is coming loose. If this is the case, the tanks should be opened up (with holes in the rear baffle) and cleaned out anyway.

[Sam Buchanan]

If it's 15 years old, it most likely has slosh compound that is coming loose. If this is the case, the tanks should be opened up (with holes in the rear baffle) and cleaned out anyway.

Or replaced. We had an RV-4 of similar vintage on the field and slosh was coming loose in both tanks. The owner, who isn't a builder, opened up one tank and after trying to clean out slosh for awhile decided his RV-4 was going to get new tanks. He bought a set from Evan Johnson.

A stray piece of slosh wrapped around a fuel pickup is not a good thing.

[49clipper]

Anyone know what the chemical makeup of the white sloshing compound is? I need to find what will remove it inside my tanks. My tanks were built by Phlogisten in Oregon back in about 1990. I have heard MEK is the thing, but also looking for options, maybe Acetone or others.
Jim

[Planecrazy232]

I was having the same problem in non-sloshed tanks. After sweating the job I ended up cutting holes in the rear baffles and sealed with proseal from the inside. It was a piece of cake.