'29 Model A RH drive gas tank leak
 

A friend asked me to help get his A going after sitting 4+ years. A few days into it, he said "Oh, by the way, the tank leaks." I put in about a quart of fuel, and noticed it leaking out the bottom of the tank a few inches from the shut-off valve. A very small leak, but the area looks like it has been worked on before. Can a small crack be sealed from the outside, or do I have to remove/replace the tank? It looks like a VERY involved job. How exactly do you take one of these things out?
Dave

Re: '29 Model A RH drive gas tank leak
 

Hmmm, most leaks originate around the steering wheel bracket where it hangs under the tank. Is this true of yours? Yes, any leak can be repaired from the outside. If it is a 'split' then any good panel shop could do the job for you. Mig weld and grinder should do the trick.

To fix this sort of leak 'in place' is possible but the tank would need to be ventilated super-well! Using lead-fill (solder) is probably the best way to seal a leak around here but doing it in-place would be tricky. heat + fuel vapour = boom.

Removing the tank isn't impossible if really necessary but will probably take half a day. It can be tricky or easy, depending on your luck. Disconnect and remove everything associated with the firewall, remove the interior kick panels, and the 'dash' panel under the windshield.

The tank is bolted along the lower firewall, across the dash (under the windshield) and along the tops of both front quarter panels (there are also 'clamps' here that can require some convincing to come out. Pry the 'jaws' of these clamps open a little if needed).

The tank will lift out. There is fender welt across the top you will want to leave in place.

Good luck!

Gus

Re: '29 Model A RH drive gas tank leak
 

I would not try and fix it in place unless you use an epoxy based tank snake oil .

Seen too many tanks blown up in faces when applying heat.

Even a soldering iron can cause a spark.

I always remove any tank and first sandblast the crack/hole, then fill the tank with water to the brim, then upend the tank so the fault is at the highest point.

Then you can weld or solder or whatever without fear of explosion in your face.

You have to eliminate the air (oxygen) in the tank

Re: '29 Model A RH drive gas tank leak
 

You can either full the tank with water to prevent an explosion or I have seen people fill them with exhaust fumes (Carbon monoxide is inert) -Karl

Re: '29 Model A RH drive gas tank leak
 

From this site .....

http://www.engineeringtoolbox.com/cl...ses-d_838.html

I see carbon monoxide is a flammable gas ?

--------------------------------------------------
Compressed gases can be classified as

• oxidizers
• inert gases
• flammable gases

Oxidizers

Oxidizers are not flammable by them self, but will contribute to combustion as an oxidant. Fat or oil is not acceptable in combination with oxidizers.
Some common oxidizers:

• Air
• Chlorine
• Fluorine
• Nitric Oxide
• Nitrogen Dioxide
• Oxygen

Inert gases

Inert gases do not take part in combustion processes and they do not react with other materials. An inert gas supplied to a room or limited space will reduce the amount of oxygen and limit a combustion process of a fire. Inert gases are used in extinguishing systems where it is important to avoid water damage - rooms with electronic devices etc.
Some inert gases:

• Argon
• Carbon Dioxide
• Helium
• Neon
• Nitrogen
• Xenon

Flammable gases

Flammable gases together with air or oxygen in the right concentration burns or explodes if ignited.
If the mixture is to lean or to rich the mixture will not ignite.
Some flammable gases:

• Acetylene
• Ammonia
• Arsine
• Butane
• Carbon Monoxide
• Cyclopropane
• Ethane
• Ethylene
• Ethyl Chloride
• Hydrogen
• Isobutan
• Methane
• Methyl Chloride
• Propane
• Propylene
• Silane

• Ignition concentration limits flammable gases

Re: '29 Model A RH drive gas tank leak
 

What about one of those co2 canisters from paintball/airsoft/pellet guns? Flood the tank with CO2 as used in fire extinguishers.

Re: '29 Model A RH drive gas tank leak
 

Dry Ice (CO2)

Re: '29 Model A RH drive gas tank leak
 

I'm 64, I have been repairing gas tanks since I was 16 and have done dozens of them.
I either use a soldering iron without the flame on or put the tank on the exhaust of our workshop truck. Never had a failure with either of these methods. I don't know if the carbon monoxide kills the inflamables or just the heat dries out any traces of fuel but it works for me. I have soldered Model A tanks in place by tinning only one face of the iron as the solder applied does'nt run down to the opposite side of the iron.

Re: '29 Model A RH drive gas tank leak
 

Had a welder (metal whisperer) friend of mine weld a square tank on a stump grinder for me. It was leaking where the spout was welded to the tank from new. He used argon (I believe) directly in the tank with a rag stuffed in beside the line/hose. I still hid behind a metal break he had in his shop while he did the weld. He laughed at me and explained the process. He had worked on lots of nuclear stuff welding. He was a Yankee that had moved south and stayed, there's a name for those Yankees :). He was a very good friend who we unfortunately lost a few years ago to heart disease.

Re: '29 Model A RH drive gas tank leak
 

I once soldered a leak in a gas tank using an electric soldering gun, first, drained as much gas as possible, jacked up one side of the car to get any remaining gas on the other side, cleaned the area of the leak w/sand paper, put soldering paste on the area, used a piece of sheet copper about 1" square, cleaned and tinned the edges of the patch, put the patch in place and soldered it all the way around.

Re: '29 Model A RH drive gas tank leak
 

See my reply today to a similar query titled "Chemist needed". Both repairs were on RHD cars and done without removing the tanks.
SAJ in NZ