New or repaired fuel tanks for 308?

FWIW 308 fuel tanks are aluminum.

 

Pin holes / general corrosion in the bottom of the older Ferrari fuel tanks is a very common occurrence. You need to cut out the affected areas, weld in new plate and pressure test the tank. Not an easy task for the average aluminum welder but perfectly feasible. In other words, repairing is the preferred way to go if the affected areas are limited in size and if (And only if) you know a trusted welder that are experienced with working in old "contaminated" aluminum. Otherwise buy replacement tanks. Nothing wrong with buying used tanks if you make a thorough pre-buying inspection from the inside of the tank.

Best, Peter

 

Wow, very interesting and thank you... pictures tell a thousand words. After the pinholes are addressed (e.g. welding sections) would POR-15 be a viable option to help ensure sealing and (hopefully) perclude additional corrosion?

 

I believe the tanks suffer from galvanic corrosion because they are aluminum and they are mounted in a steel car.

I have replaced both tanks in my gt4 a couple of times in the nearly 40 years I have owned it (with secondhand tanks). The good news is that if you have collected secondhand tanks as spares, they don't corrode outside the car.

Last time I looked new tanks were available at around GBP1K each.

 

What about an epoxy resin two pack coat ?

Just flying flags guys don’t bite my head off .I had a 8 gallon military style Gerry can ( was stud on bare earth ) developed pin holes in its base .Roughed up the surface and built up a few layers exterior of twin pack epoxy .Been fine ever since .Obviously the failure mode was just seeping into the ground .Not as potentially damaging as weepy tanks on a GT 4 with the hot exhaust down stream in the line of fire etc .

 

I would think replacing aluminum sections would be better than epoxy - it just seems like a bandage that will eventually unstick. Sure there are impurities but if properly treated and ground out before welding, most of those would be taken care of to a certain degree. I'm not a welder but I watch people do it a lot so take my advice with a grain of salt. If you're not really a concourse guy, go get something new made that fits and works from a local fab shop.

 

Not sure if this is one of what you are looking for?

 

I posted a similar post in another thread about fuel tanks a few months ago, but I had the fuel tank in my 240Z sumped during an EFI conversion, which caused it sweat out a bunch of lead sealer on its pinch seam around the whole edge of the tank. It would slowly seep fuel -- very not good. I was about to throw the tank in the trash and start over with a fuel cell.

Before doing that, I did the POR 15 fuel tank repair kit on it: https://por15.com/products/fuel-tank-repair-kit Don't get me wrong, it was a LOT of work doing the kit right, but the result has been fantastic. The tank has been completely sealed with no leaks for 5 years now, has done thousands of miles on hot and cold days, and generally sits with a completely full tank of E10 premium or whatever they normally have at the gas station, in my shop. I would definitely use this kit again, and personally I think it would be a more than reasonable choice in this situation rather than going straight for new tanks.

 

I think a big challenge to coating the inside is getting even coverage. Doesn't the OEM tank have a bunch of internal baffles?

 

That's a bummer. It says "In Stock" too.

 

One of the reasons there is so much work involved, is the amount of time you have to spend rolling the tanks around to ensure coverage. You end up taping the tank shut with the sealant inside and rolling it around for 20 minutes prior to draining it and letting it sit for 96 hours. I would imagine if you're rolling it in every direction for the prescribed amount of time you'll do a thorough job getting all of the baffles

 

Interesting to hear the treatments here. I would want to understand if the ethanol added into car gas would have any impact. Avgas is usually ethanol free.

 

The place to find custom tanks is the Boating Industry.

I would think with careful planning and your old ones as patterns, fresh metal all around is the way forward??

 

You can easily repair fuel tank leaks with an aviation product called Proseal. It works very well.

 

A few minor mods on a new tank would be well worth it., IMO.