Fuel Tank Repair

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

M Beauchamp

Well-known member
Joined
Aug 15, 2011
Messages
392
Reaction score
5
Location
Sarnia Ontario
My Car
1973 light blue convertible
351c 2V
How to repair a leaking, dented gas tank.

I could have purchased a new tank for $120 plus freight.

But I wanted to see if this tank could be repaired.

The repair took 6-8 hours.

First thing is clean the fuel out of the tank and flush it until all of the fumes are gone!

Here is the tank with dents and holes.

1.1.jpg

1.2.jpg

1.jpg

This picture you can see where the factory seam weld was.

2.jpg

Take a zip cut wheel and grind a grove just on the inside of the existing seam weld.

Only grind threw the top sheet metal on all four sides.

The sheet metal will turn blue as it thins out, Don't grind into the bottom sheet metal.

3.jpg

Take a cold chisel to separate the top sheet metal.

4.jpg

Pull the top and bottom apart.

6.0.jpg

Here you can see the bottom lip.

6.1.jpg

Here you can see the top lip, as well as all the rust that builds up and get in the fuel system.

7.jpg

Straighten the top lip out with a dolley and hammer, so it will lay flat when you weld it back together.

8.jpg

Blast the top and bottom pieces of the tank in and out.

9.jpg

10.jpg

The pin holes are hard to see, using a flash light behind helps locate them.

11.jpg

12.jpg

Do all your spot welding on the inside of the tank using a copper backing plate, this will save alot of grinding later.

13.jpg

Grind of the weld penatration the pops threw the sheet metal.

14.0.jpg

14.1.jpg

Dolley and hammer all the dents out.

15.jpg

16.jpg

Fit the Halves together.

Use vise grips to keep the sheets tight for welding.

Start at one corner and work around all four sides.

This allows you to tweek the grove back into the same location.

Tack weld about every three inches.

Grind all the tacks smooth so the seal weld can pass over them nicely.

17.jpg

Set the tank up on a 45 degree angle so the seam can be re-welded in a down hand position.

18.jpg

When welding ensure that the puddle fuses the sheet metal on both sides of the zip cut grove.

Use a slight whipping motion with the arc, backing up about 1/8" this lets you fix the weld puddle if it you loose the sheet metal on one side.

Repeat this welding on all four sides.

19.jpg

Here you can see the weld penatration on the back side of the seam.

Grind up any welds.

100_2853.JPG

Use a polymer fuel tank liner to seal the entire interor of the tank.

This prevents rust from forming inside the tank and getting into the fuel system.

Tape up the openings.

100_2854.JPG

Pour the polymer liner into the tank.

100_2857.JPG

Tape the last opening and slowly rotate the tank.

100_2858.JPG

Use a flash light to see that the entire interior of the tank is coated.

Pour the excess polymer out of the tank.

Let dry for 24 hrs

100_2861.JPG

Paint the exterior of the tank with 2 coats of epoxy paint.

Reinstall the sending unit, vent plug and nozzle gasket.

 
Last edited by a moderator:
Excellent work and great write up. I wouldn't and didn't have the courage to do this but it is good to know it can be done.

 
Great write-up! Its great to save original parts like that if you have the time and know how, but if you had to pay for 6 hours of labor it probably more economical to buy one.

 
Nice write up & nice work to showcase your skills ..But 8 hours of my time @ say $50.00=$400.00 +$100.00 in materials =$500.00 I understand why you did it but I'd buy a new one for the $120.00 before investing that amount of time into a questionable part.

 
Last edited by a moderator:
I think its great you have skills like that and the time to do the repair. My dad was great at stuff like that. I remember one time back in the 60's the fuel pump went out on our Pontiac late at night about 200 miles away from home. He cut a leather diaphragm out of my mothers shoe, replaced the diaphragm in the old fuel pump and got us home safe and sound. He ran that fuel pump for several more months before replacing it; of course my mother was not too happy about her shoes.

Anyway, great job!

 
Fantastic job, just goes to show how something can be brought back from the dead.

 
Back
Top