View Full Version : Fuek Tank Repair or Replace

12-19-2007, 11:20 AM
I've got a hole in my gas tank.


Should I replace the gas tank, or attempt to have it repaired. The rest of the bottom of the tank looks solid, although very pitted with rust.


It's a bit more than just a hole. The hole is about as big as a large screw driver blade, but then a crack extends on either end of it for about an inch. The metal in that area is as thin and weak as tin foil.

A repair would need to cover about 5 inches, starting at the edge of the tank and extending to both transitions front and rear. I think the damage is confined to just this one area.

12-19-2007, 11:49 AM
I'd replace it. You'd have to weld after removing all of the rust and I suspect it's pretty thin there then get a pro sealing job for the other pinholes etc.
I'd rather the security of a new unit.

12-19-2007, 12:01 PM
I replaced mine after it developed a similar leak because the whole bottom was thin and rusty.

12-19-2007, 12:01 PM
I'm tempted to try a repair, with the caveat that I replace the tank as soon as funds are available. I can probably get a repair attempted for no out of pocket expense.

I think the tank is otherwise solid. The pitting is bad, but there's nothing through the metal that I can see.

12-19-2007, 12:14 PM
Some things I'll 'recycle' to save some dough but not safety items.
Of course all I can see is the photo so you know better with sight and feel.
The problem is you can spend a lot of money/time fixing a bad part and still have a bad part.
The car won't be mobile for awhile so why not wait until the tank is critical to completion and see how you feel then.

12-19-2007, 12:28 PM
If you are going to try to repair that tank, I would take it to a radiator shop, have it acid dipped, then look to see how bad those pitted area really are. I'm betting they are worse then you think.

Also, be sure that all the gas vapors are gone from that tank, or kaboom, and you will become a statistic.

If it were mine, I buy a new one.

12-19-2007, 01:04 PM
Well... my goal was to get the tank installed, and the rear boot cover installed, and call it done. I need to verify my fuel lines are intact and a few other things before I can do that, but that was on my "short list," i.e. stuff I can actually do with the parts I have.

The tank's been empty for 5 years.

12-19-2007, 01:12 PM
Hi There rlandrum;

I agree with "EVERYONE" here!


We all can`t be wrong!

Replace it! As Ray mentions; You have physical pits that don`t look bad but you can bet that they are probably worse than the eye can see!!!!!

Good Luck & "BE SAFE";

Regards, Russ

12-19-2007, 01:57 PM
Penny wise Dollar fuelish!!!!

12-19-2007, 02:09 PM
Wow... lots of flak for suggesting I repair it.

I don't really believe it's repairable... And everyone seems to have confirmed my suspicions. But I'm going to see if the guy welding up my carb will do this as a favor to me. If it leaks so much as a drop, I won't use it, not even temporarily as I don't want it to destroy my nice wool felt and new trunk rattle can paint job.

Chances are, he won't be able to do anything with it. If he does manage to repair it, and it doesn't leak, I'm still going to replace it.

12-19-2007, 02:12 PM
Again the minority opinion : I've repaired fuel tanks in two different TR3s now and it worked out very well both times. First one was over 30 years ago, and it still holds fuel (AFAIK, sitting in Dad's shed). Second one was almost 20 years ago, and it still holds fuel. Not saying it wouldn't be safer to have it professionally repaired or replaced with new ... just that I don't feel it's all that dangerous to repair yourself.

What I did both times was repeatedly flush the tank with water, by first filling it to overflowing (so any trace of liquid fuel rises to the top and gets flushed away, plus all vapors are expelled) then letting it drain and dry in the sun a bit. Once I could not even smell fuel inside, I felt confident the concentration was too low to burn.

Then I wire brushed and sanded the area thoroughly, and used a propane torch, acid flux and soft (plumbing) solder to 'butter' the pitted areas. On the second tank, I even had to make some small patch panels from a flattened tin can, as some of the holes were too large to bridge with solder. Used water to check for leaks. When I was satisfied there wasn't so much as a damp spot after several hours, I emptied and warmed it with the torch to drive off the water, then lightly sanded and painted the entire tank exterior.

YMMV of course. Today I'd still look for lead-based solder, the "no lead" stuff sold for plumbing is much harder to work with IMO.

Another "flameless" option would be fiberglass, or fiberglass cloth coated with JB Weld. But you still have to get the surface absolutely free of any fuel, oil or paint, to get good adhesion.

12-19-2007, 02:55 PM
Fill the tank with Nitrogen, This will purge without adding anything "unfortunate"

12-19-2007, 08:04 PM
Repair it. If you do it right with a sealer, see link, about 60$


POR15 also has a kit similar to KBS.

Finding a welder that will weld a fuel tank can be difficult and they usually charge a good bit to "take the risk". Nevermind trying to convince them that if there are no vapors there can't be an explosion. One guy told me that the steel soaks up the fuel and releases it when heated!!! All welders know someone that was killed welding a tank or at least has lost fingers doing same.

Clean it out with a solvent or marine clean and flush the solvent with soap + water until there are no vapors of solvent left, cut the patch, weld it up, and truck it on!

I did this on a pair of old aluminum tanks for an airplane with no problems.

12-19-2007, 08:42 PM
IF I were going to repair YOUR tank, I would want to cut the entire bottom out of it and replace ALL of the removed material with new. {I have done a few this way} With the bottom removed, an assement can be made as to the integrity of the rest of the tank {sides and top}. There is a SLIGHT possibility that the original bottom could be repaired and replaced, however I have found that in most cases the corrosion is usualy worse than expected and not worth trying to repair. ANY NON FLAMABLE gas can be used for a purge I.E. Co2, Argon, Nitrogen, ETC.
The main consideration is, how available is a NEW tank?
What will the cost difference between repair and purchasing new be?
Welder labor rates are pretty pricy! {I would charge $25.00 per hr.} + materials
Most get $25.00 per hr for the machine and another 25.00 Per Hr. labor + materials.
A new tank is most likely the way to go.
IF you can afford and find one Stainless Steel would be the best. You will never ever have to worry about the gas tank again in your or your childerns lifetimes.

12-20-2007, 03:29 AM
Mine was so trashed out that even after getting it repaired, welded, coated, etc., it still leaked. I realize that funds for you are important (as they are for anyone) but I bit the bullet and went with an aluminum tank from Moss. Had to have some extra holes welded over (for fuel injection and electric pump) but now have no problems with tank. Also, if your car has been sitting for all these years, consider pulling the fuel lines (they are just steel) and either reaming them or re-bending some new ones out of 5/16th stock fuel lines. These are really cheap and readily available at all retail vendors.

12-20-2007, 05:43 AM
Wow... lots of flak for suggesting I repair it.

Take it as a sign that everyone is concerned about your well being rather than flack! As a group I think everyone tries to error on the side of caution...

12-20-2007, 06:22 AM
Don't try to Pedro-ize your own tank !!

Everything Pedro-ized eventually falls apart and will
leave you stranded waiting for the flatbed tow truck
to arrive. Belive me, I know.

In this case, you could catch yourself on fire
or blow up.

"Be wise-don't Pedro-ize!" /bcforum/images/%%GRAEMLIN_URL%%/savewave.gif


12-20-2007, 02:57 PM
I'm perfectly willing to repair a sound tank that has gotten punctured. But in that picture, that doesn't appear to be the case. There's a good bit of fracturing, and the metal appears thin. You'd have to run a large patch, and I honestly don't know that it would hold.

12-20-2007, 09:01 PM
Every good end result comes with some risk. Be
cautious; weigh the risks and the costs.
Whatever you decide, I'll pray for you a good

I'll read you to post another day.


12-21-2007, 11:11 AM
I took the advice of the list and proceeded with caution... I used a blunt file to test the strength of the bottom of the tank. I put about 40 little holes in the tank with very little pressure.

So I took it to the guy who welded up my carb flange (which looks fantastic), and he said he could repair it. He had me sand blast it (and I definitely need a sand blasting cabinet now), and other than the bottom, the metal was strong and unpitted. He's going to replace everything two inches into the good metal both front and rear of the rusted area, and replace the fuel outlet and drain with slightly more modern pieces, since saving them wouldn't be possible.

I traded him an unused (and unwanted) Jeep inline 6 block, crank, and pistons, for the work, making it free... /bcforum/images/%%GRAEMLIN_URL%%/smile.gif I may need to cover some material costs, though.

12-21-2007, 12:54 PM
You were quite generous, I think. Glad to hear you
acheived the objective. Best of luck and keep

12-21-2007, 01:14 PM
One other thing... The fuel outlet fitting was made of brass. It looked to be NPT, but when I tried to thread in a possible replacement, it stopped after about 1 thread worth, which made me suspect that it may not be NPT.

Anyone know what it was?

12-21-2007, 01:39 PM
Should be a parallel SAE thread, but I don't recall which one offhand. It's a compression fitting (with reverse nut), not a tapered 'pipe' fitting.