braising gas tank

[chistech]

This thread is really cooking now!

[13CADDY]

and Ted,you just lit the fire !

[babychadwick]

No magnesium here, just rock and steel "dialed in right"

 

On the topic of fuel tanks I have friends that Very frequently deal with bad tanks, part of living on an Island with many boats.  Rather than plug etc as they are dealing with aluminum and cut out bad sections or fill holes by welding.  Often these tanks are in excess of 100 gallons.  As preparation tanks are filled with water prior to welding then welded. 

[Restorer32]

Large propane tanks, say 10000 gallon ones,⁹ are pressure tested in the same manner. They are filled 99% with water then pressure is applied. Since water does not compress 1000 pounds pressure applied to a very small quantity of gas pressurizes the entire tank and is much safer.

 

[Locomobile]

52 minutes ago, Restorer32 said:

Large propane tanks, say 10000 gallon ones,⁹ are pressure tested in the same manner. They are filled 99% with water then pressure is applied. Since water does not compress 1000 pounds pressure applied to a very small quantity of gas pressurizes the entire tank and is much safer.

 

 

In a hydrostatic test like described above, there is no air, the test equipment is designed to vent all air from the vessel. Non pressurized tanks should never be tested by hydrostatic means. High levels of pressure which could damage the tank can be introduced very quickly even with temperature change.

 

Any air trapped can compress and store energy. Hydro tests are generally performed with heated water which drives dissolved oxygen out. All pressure vessels are hydro tested for certification.

 

Someone mentioned that Mapp gas can not be used for soldering, this water tank was soldered entirely with propane and Mapp gas. 2-1/2 pounds of lead. That welder rep had no idea what he was talking about.

 

For repairing an automotive fuel tank, I would remove it, empty it, remove the sending unit, purge it with air and then repair it with Muggyweld SSF-6 Silver solder. That soldering them full of gas can work but it is very dangerous. Many fires over the years around here from people doing that, gasoline is sneaky and volatile.  Not to mention, the insurance company would not be too understanding. I had a kerosene fuel tank whoof on me pretty good once, but I had everything open on it and there was no explosion, that is what's important.

 

-Ron

 

 

[Restorer32]

Reminds me of the early '60s car that came into the shop for body work. Someone had installed an aftermarket tow hitch. 2 bolts held it to the bumper. In addition there was a long brace which went back under the car. Someone had welded that brace directly to the bottom of the gas tank. 

 

[Stude17]

From reading this post I see that many ideas/methods have been put forward to purge a fuel tank of petrol fumes before repair.   Before working on a tank I use fairly warm water with a liberal dose of washing up detergent to slosh around the tank.  I generally do this at least three times. This method was taught to me by the old workshop foreman when I would be given fuel tanks to repair when doing my apprenticeship as a Fitter and Turner a long time ago.  I have not seen any method in this post to change my procedure for auto tanks but it is up to each and everyone of us to make our own decision on how to do it.  Working on fuel tanks is dangerous and not to be taken lightly.

[trini]

Can you not get a steam pot or a steam cooker, direct the steam through a heater hose into one hole and let the steam out through another hole. That will get the fumes out and if the steam is intense enough it will certainly get some rust out. Please do not paint inside tank unless it is some special stuff made for that purpose.