markwemple
markwemple UberDork
5/26/18 11:28 a.m.

Just tried permatex. Total crap! Barely slowed the leaks and I was able to pop the repairs off. I had wire brushed and brake cleaned the areas and let them dry. Gave it over 24 hours before testing. So which ones have you had success with?

barefootskater
barefootskater Reader
5/26/18 12:14 p.m.

Plastic tank or metals?

markwemple
markwemple UberDork
5/26/18 12:35 p.m.

Metal

AAZCD
AAZCD New Reader
5/26/18 12:45 p.m.

I used a bar of soap about 20 years ago on my Jeep Cherokee. I just rubbed the bar back and forth over the dripping leak and it stopped. About two weeks later, I replaced the tank and it was still holding well. I wouldn't feel comfortable with it as a permanent fix.

barefootskater
barefootskater Reader
5/26/18 1:07 p.m.

Shoot. I have no solutions to offer other than welding or brazing. Nothing permanent anyway.

markwemple
markwemple UberDork
5/26/18 1:45 p.m.

On a MC forum a guy suggested denting in the area them melting into it lead from fishing weights. Thoughts??

AAZCD
AAZCD New Reader
5/26/18 4:56 p.m.

I work in EMS and haven't seen a car gas tank blow up that wasn't already on fire, but I have seen:

A mechanic was welding while he sat on a gas can. He will not have children.

A guy cutting an 'empty' 55 gallon drum to make a BBQ grill. Lost most of his face. I think they were able to restore vision to the remaining eye.

Be very cautious of igniting fumes. Have you considered just replacing the tank? I've replaced gas tanks on 2 cars and removed them from a few more. It wasn't that bad.

markwemple
markwemple UberDork
5/26/18 5:32 p.m.

Ducati tank. Cheap end appears to be 600. Hasn't held gas for a decade. been soaking in rust remover. Shouldn't be combustible 

Gaunt596
Gaunt596 Reader
5/26/18 7:19 p.m.
markwemple said:

Ducati tank. Cheap end appears to be 600. Hasn't held gas for a decade. been soaking in rust remover. Shouldn't be combustible 

Some rust remover is combustible, and just about any chemical made will  combust under the right conditions

Donebrokeit
Donebrokeit SuperDork
5/26/18 8:50 p.m.

In reply to markwemple :

Mark, the lead this is old school but it should work. Can you put a bladder inside the tank?

 

Paul B

markwemple
markwemple UberDork
5/26/18 9:00 p.m.

In reply to Donebrokeit :

Not sure about the bladder but the lead trick should be same technique as sweating pipes or radiator tanks, I think. Those seal fine if properly cleaned and fluxed. For some reason it feels as though its closer to a permanent repair and safer than welding.

dean1484
dean1484 MegaDork
5/27/18 7:30 a.m.

A good radiator shop should be able to solder it up for you.  

If you are going to try the DYI use an Iron to solder it. 

AAZCD
AAZCD New Reader
5/27/18 7:53 a.m.

Solder sounds good. JB Weld 'TankWeld' would be my choice for an epoxy repair. Whatever you do make sure that you do good surface prep. Make the repair to a clean metal surface that has been textured for adhesion (fine sandpaper or Dremel Tool). Wipe with Isopropyl and dry before sealing. Got Pics?

Kramer
Kramer Dork
5/27/18 10:00 a.m.

The repair putty only works if you have a perfect bullet hole in a rust-free area not near a seam.  Any rust, or near a seam, and it won't work.  Period.

dean1484
dean1484 MegaDork
5/27/18 12:30 p.m.

Guess the time I used epoxy puddy to seal up the top of a rx7 tank the was Swiss cheese from rust was a fluke?  Except I did it to several cars when I was young and had no money.  There was a time when I was getting my cars from the junk yard and you did what you had to do. I had lots of time but no money.  Absolutely not safe but it worked. The key is to cleaning them really well. I would fill the tank with water and then wet sand the areas with a strong detergent of some sort. Don’t remember what brand but it was before dawn came out.   Three or four hours spent doing this was the norm. Looking back on it here we were worried about blowing our self up while doing the repair to make something that could blow us up while driving. Ya that was a well thought out plan. LOL. 

Kramer
Kramer Dork
5/27/18 1:20 p.m.
dean1484 said:

Guess the time I used epoxy puddy to seal up the top of a rx7 tank the was Swiss cheese from rust was a fluke?  

Sounds like you removed all the rust. 

eebasist
eebasist Reader
5/27/18 4:18 p.m.

In reply to Kramer :

How big is the hole? May work on seams and porous areas

https://www.kbs-coatings.com/large-cycle-tank-sealer-kit.html

Kramer
Kramer Dork
5/27/18 4:44 p.m.

I don't have a hole in my fuel tank.  I haven't had this problem since 1987.  I sold that car with a leaky tank.  I've sold fuel tank repair kits and products since 1988, though.  And I grew up around restored tractors and equipment.  Fuel tank liner products often seem to peel and clog up fuel filters.  Tractor restorers use them often.  I've heard of many failures.  My dad has a tractor with a lined tank, though, and it hasn't peeled.  

I get asked all the time if these things work. I tell them it's like a bandaid.  If you cut your finger, it may work. If you cut your head off, it probably won't work.  It all depends on the nature of the cut (or hole in your tank).  I'm sure someone will correct me and tell me they fixed the rustiest tank near the seam. I'm just saying the odds are against it working if there is rust, or if the hole is near a seam. 

Carl Heideman
Carl Heideman
5/29/18 7:09 a.m.

I've used a product called "Seal All" for many years for pinhole leaks on gas tanks, even rusty ones.  I just wire brush and clean the affected area as well as possible, put some Seal All on, and wait overnight.  I've had the repairs last over 10 years in some cases.  It's cheap and available at most hardware stores.  Apparently Walmart has it too--that's the first link that came up when I googled it:  https://www.walmart.com/ip/Seal-all-380112-Multi-Purpose-Contact-Adhesive-2-oz-Clear-Liquid/22217286?wmlspartner=wlpa&selectedSellerId=282&adid=22222222227016836217&wl0=&wl1=g&wl2=c&wl3=51797601071&wl4=pla-83199963191&wl5=9017486&wl6=&wl7=&wl8=&wl9=pla&wl10=111838817&wl11=online&wl12=22217286&wl13=&veh=sem

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) UberDork
11/1/20 7:38 a.m.

I epoxied the tanks in two of my long term cars. Just pinholes, and neither from rust or on a seam. It's been a long time, but I may have had an initial failure with the Walmart stuff.

Both held up for years. I don't remember the brands, but I recall having used the epoxy that comes in a tubular shape with an inner core of one component surrounded by the other. Cut off a piece, mix together. 

As always, prep is crucial to success.

One of the holes was in the bottom of the tank. It was just a pinhole, so I enlarged it slightly and let the tank drain for at least a week, until it was fully dry.

Sanded, cleaned with acetone, let dry for a few hours, and did the repair. I had the car at least another 10 years, may have had to repeat the repair once.

petemc53555
petemc53555 New Reader
11/1/20 7:45 a.m.

POR15 makes a gas tank sealing kit.

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