Leaking FUEL TANK

[kartone]

The current tank in my 1980 GTV has already been repaired with a top brand internal "rubber"coating, well after a year or so it has started leaking AGAIN  .
Are plastic tanks available as a substitute ? Does anyone have a steel tank in good condition for sale ?

[Alfapride]

I recently repaired my tank with por-15 kit

http://www.porcan.com/content/14-por-15-fuel-tank-repair-kit

I also had the outside primed and powdercoated plus replaced the gasket where the fuel sender fits

This solved my problems and cleans the tank out very well

[kartone]

Alfapride, that's the product I used on a perfectly clean interior surface (no rust or any type of oxidization). I cold-welded the hair-line crack and bead-blasted, primed and painted the outside.
IT'S NOW LEAKING AGAIN   

[Alfapride]

Where's it leaking from? How's the gasket to the sender and hoses? If it's clean internally a repair to sill should be ok to do I believe? Alfaholics sell new ones

[kartone]

It's leaking from the bottom of the tank, to be exact from one of the creases stamped on the bottom to give the tank more rigidity; instead of having a radius the crease was pinched during the stamping process and over time developed an hair-line crack. The inside was like new, I followed the instructions to a T and used a whole container of POR, coating all sides evenly.   

[brook308]

I've welded a leaking tank and installed fuel foam in a couple then welded them up.
I pull the tank out then flush it with water.
Before welding or cutting I use the exhaust flow from a modern car to evacuate any residual gas from the tank.

But if your not up for this much adventure take it to a welding shop and have them repair the tank.
Or if you're nearby the sunny coast I might have a spare tank.

[kartone]

Brook308, I am concerned what the heat from welding or soldering will do to the Red-Kote epoxy lining.
I need to remove the epoxy first, will swirling acetone inside the tank do it?
Once removed I can contemplate welding. 

[colcol]

Soldering will put less heat on the tank and less likely to warp it, welding also introduces flames to petrol fumes, after the explosion, as they say, after they put out the fire, 'Worksafe are investigating', so fill the tank with water, but the heat will melt the epoxy lining.
I went through all this palava with my first car, until i found a plastic fuel tank that ended all these problems, yhe water sits on the bottom of the tank and rusts it, Colin.

[brook308]

Soldering will put less heat on the tank and less likely to warp it, welding also introduces flames to petrol fumes, after the explosion, as they say, after they put out the fire, 'Worksafe are investigating', so fill the tank with water, but the heat will melt the epoxy lining.
I went through all this palava with my first car, until i found a plastic fuel tank that ended all these problems, yhe water sits on the bottom of the tank and rusts it, Colin.

Careful slow welding will not warp an alfetta tank,
You dry the tank out after you've finished, leave it drain in the sun and Mother Nature will have it nice and dry in a few hours.

Good point though if you've coated the tank internally then the welding process will burn this coating.
Once the welding is done I'd just try flushing the tank again with water to wash out any loose burnt coating.

There's guaze on the pickup in the tank and you still have your fuel filter to pickup any crap before it gets to the carbs, and the the carbs have a guaze filter on their banjo fittings.

[kartone]

We have 3x2x2m caustic baths at work 

[kartone]

Outcome: Caustic at 65C temperature does not affect RedKote epoxy 
Next, industrial oven at 185C to convert epoxy into ash as outlined in material spec sheet 

[aggie57]

These tanks can crack due to years of heat expansion / contraction.  The ridges only serve, in that case, to create a point of weakness where the cracks can start.  So once you have a problem in one place the probability of the same issue elsewhere should not be discounted. 

[kartone]

Update: Inspected the inside of the tank and found that the bottom of the tank in flexing / vibrating  would hit the fuel pick-up pipe which "chiseled" its way through the Red-Kote membrane  .
Have enquired with Red-Kote whether it is possible to re-coat just the bottom. 

[colcol]

The fuel pickup sits very close to the bottom of the tank, so any coating is going to affect the pickup, you may be able to bend the pickup pipe, so it sits a bit higher off the bottom of the tank, but miss out on a litre or so of fuel, Colin.

[kartone]

have already bent pick-up pipe, now approximately 10mm of tank surface; waiting on reply from Red-Kote reagarding recoating