braising gas tank

[broker-len]

is there a safe way to put a patch in a gas tank ???????

[mike6024]

I brazed some holes shut using a plumbers propane torch with a cylinder of MAPP gas and a fluxed brazing rod. No fumes in the gas tank, of course. You can braze with MAPP gas, it gets hotter than propane.

[Bloo]

I'm not knocking that, but you can get by just fine with soft solder on a gas tank, that is what a radiator shop would do.

 

The fumes are a problem. It makes me nervous as hell. First choice back in the day was to take it to the radiator shop. They can boil it out and get rid of the gasoline scum that is the source of the fumes and of course they are all ready with solder and torches too. The trouble is, there aren't many radiator shops left.

 

Another old method it to fill the tank with CO2. You leave a little bit of flow to make sure there is no oxygen in the tank. IIRC the CO2 is heavier than air, so you want the opening at the top.

 

Yet another way is to fill the tank with water, with the damaged area at the top just barely out of the water. You can't have the water screwing up your solder job, but the tank really needs to be almost completely full, so that there isn't room for fumes. Any fumes that exist are going to burn. Don't blow yourself up.

 

I recommend talking someone else into doing it.

 

 

[Frank DuVal]

I use an old American Beauty 100 watt soldering iron. I unplug it after it gets hot, just to make sure there is no spark. Flux, then solder to tin the area.

 

Using a wire brush is more scary to me than touching an unplugged soldering iron to the tank, wire brushes make sparks! You can always make a jumper wire to electrically attach the soldering iron to the tank to insure there will be no sparks.

 

Small holes can be soldered closed (1/8"). Larger holes may get a sheet metal screw (cleaned, ready for solder) inserted, then soldered in place. Larger holes get a piece of copper (flashing works great) tinned then placed over large hole and sweated in place with large iron.

 

Only ever used a torch of any type to install filler necks and other such large metal parts. Then the above NO FUMES warning holds!

 

Buying a new tank is always safer....👍

[Bush Mechanic]

Eric Gange's Garage, near where I grew up, had this problem sorted.  Remove tank, drain petrol, face tank across the yard toward the paling fence, and insert lighted oxy torch in the filler neck. When it bounced off the fence, it was safe to weld on. Eric was a bit rough around the edges, but he could fix most things. Personally, I'm a little more circumspect, and leave the garden hose running in the tank for a while, THEN use Eric's test. Haven't had one take off yet, but I do hold my breath.

[Isaiah]

You don’t want to use MAPP gas for brazing or soldering as it is not clean enough!

This was told to me by the Rep from the welding supply company.

mapp is used mostly for cutting and heating .

The old heavy  electric soldering Irons work well.

Rince the tank out or I put them in the electrologist tank and that gets rid of the rust and other gunk then you can wire brush it up and soldier it and you should have a good repair.

Check the spots where the bands go around the tank.

I use a old camper fibreglass bath tub to to do some of my bigger items.

Those plastic barrels works good also.

When you are done with the repair I would put one of better sealer's in the tank . this will help keep rust out of the gas line.

[Guest]

Many tanks are partially full when  leak is found.  My cousin ho ran a service station and bulk dealer in the prairies just fulled the tank right to the top and thendid the repair using his propane torch.  He said there were no fumes under the tank, so it might burn but would never explode.  It worked well for him fo many years.  Repaired lots of tanks and never had either a fire or an explosion.  I stood well back the first couple of times I watched him.

[edinmass]

Buy some dry ice, and crush it and place it in the tank. It’s pure CO2, wait about an hour and the tank will be full of inert gas. That is the best way to do it.

[cheezestaak2000]

all of those methods work, but to make it quick and easy, simply run the engine(can be from a different car), and place a hose from the tailpipe to the tank filler.that will fill the tank with carbon monoxide, and render it safe to use a torch. i've done this a few times.

[Restorer32]

A cautionary tale. A friend asked us to braze an old Harley tank that obviously had not held gas for many years. Not even the slightest trace of a gas smell. Shortly after I started heating the tank with an acetylene torch there was a loud WHOOSH accompanied by flames out the fill hole. After I ran home to change my pants I reasoned that at least now we knew it would not explode again. I was wrong. Another WHOOSH accompanied by flames. This from a tank that had not held gas for likely decades. Now we just run a hose from our Tig welder's Argon tank and let it flow while we make any needed repair. Be careful out there.

 

 

 

[mercer09]

great topic and one I need to address- I will find a radiator shop...........

[60FlatTop]

If you have perforations you probably need a patch because of the extent of thin metal. Better to open the tank right up and address the whole interior. Some cars have what you might call anti-slosh chambers where rust collects. Once you are inside you can really see.

 

Years back I had a '56 Olds with a rusty tank that I never dropped, but used as a daily driver. There were always fine rust particles in the bottom of the carb and the spark plug tips turned brown. You can live with stuff like that, but today I would cut the top out and clean it thoroughly.

Bernie

[R Walling]

 There were no after-mart gas tanks for my car, so I filled it up with water and sandblasted the whole under side, and then fiber-glassed it.

 It is still holding very well.

[plymouthcranbrook]

I have used fiberglass many times sometimes just covering the entire tank.  Never a leak even after years of use That is what I used to fix the holes on the top of my Plymouth tank 17 years ago. Then I cleaned out and coated the interior and POR 15ed the outside. No problems.

Edited July 4, 2019 by plymouthcranbrook (see edit history)

[Buffalowed Bill]

Just curious has anyone successfully used JB Weld, or a similar product for tank repair?

[Bloo]

You will find people who will tell you that works. I don't believe it. Someone suggested it to me years ago, and I put some on a piece of steel, let it cure, and then dropped it into a bottle of gasoline. After 2 days it was soft and gooey. I could stick my fingernail in it and sort of push it around.

[mercer09]

I have a tank repair material like JB Weld. Have never used it, but the guys on the Ford Barn swear by it for around where the steering column mounts to the tank.

 

no more leaks.

[Joe in Canada]

16 hours ago, edinmass said:

Buy some dry ice, and crush it and place it in the tank. It’s pure CO2, wait about an hour and the tank will be full of inert gas. That is the best way to do it.

This is the best way as Ed says. Never use water or the exhaust from a car unless you have a bomb suit handy.

[Frank DuVal]

Sure, if you have a store that sells dry ice in your area. We lost our solid CO2 source when the Ukrops grocery chain was sold to Martins/Royal Ahold (Now Ahold Delhaize).

 

Note, this does not mean I endorse exhaust method.

 

Water works well, as long as the tank is full of water. But of course, then it is hard to solder.....  Any non-liquid area in a tank will be gasoline vapors-act accordingly.😨

[capngrog]

16 hours ago, cheezestaak2000 said:

all of those methods work, but to make it quick and easy, simply run the engine(can be from a different car), and place a hose from the tailpipe to the tank filler.that will fill the tank with carbon monoxide, and render it safe to use a torch. i've done this a few times.

 

I think you meant carbon  DIoxide, not MONoxide, since carbon monoxide (CO) is an OSHA Category 1 (extremely flammable) flammable gas.  Carbon DIoxide is, of course inert, and being heavier than air is considered to be an atmosphere (air) displacing gas.

 

Be careful out there.

 

Cheers,

Grog

[PFitz]

50 minutes ago, capngrog said:

 

I think you meant carbon  DIoxide, not MONoxide, since carbon monoxide (CO) is an OSHA Category 1 (extremely flammable) flammable gas.  Carbon DIoxide is, of course inert, and being heavier than air is considered to be an atmosphere (air) displacing gas.

 

Be careful out there.

 

Cheers,

Grog

Correct.  Carbon monoxide is the blue flames you see in an anthracite coal stove fire. Antique stove guys call them "The dancing blue Ladies".

 

Paul 

[cheezestaak2000]

13 hours ago, PFitz said:

Correct.  Carbon monoxide is the blue flames you see in an anthracite coal stove fire. Antique stove guys call them "The dancing blue Ladies".

 

Paul 

i'm obviously not a chemist  lol, i just thought about the gas that kills you in auto exhaust. pretty much any non-flammable gas would work i guess

 

[Restorer32]

14 hours ago, capngrog said:

 

I think you meant carbon  DIoxide, not MONoxide, since carbon monoxide (CO) is an OSHA Category 1 (extremely flammable) flammable gas.  Carbon DIoxide is, of course inert, and being heavier than air is considered to be an atmosphere (air) displacing gas.

 

Be careful out there.

 

Cheers,

Grog

Technically carbon monoxide is not flammable.  Like oxygen, Co2 is an accelerant but will not burn by itself.

[PFitz]

57 minutes ago, cheezestaak2000 said:

i'm obviously not a chemist  lol, i just thought about the gas that kills you in auto exhaust. pretty much any non-flammable gas would work i guess

 

 S'ok. You just don't ever want to see those "Blue Ladies"  dancing around a gas tank.

 

Paul

[PFitz]

Not to nit pick but,...

 

CO2 is carbon dioxide which is inert. That's why it's used in fire extinguishers.

CO is carbon monoxide, which is indeed flammable. Like gasoline, it's even explosive when ignited with the right mixture of air. 

 

The reason carbon monoxide doesn't explode in car exhaust is because there is more CO2 and other by-product inert gases than CO in the exhaust, thus diluting it to a non flammable mixture.

 

Many an anthracite coal stove owner has had to change their underwear after the stove door was blown open when the CO and O2 were the right proportions and a flame came up through the too-much coal they just piled on and smothered the firebed, and then closed the secondary  damper too soon to dilute and carry the CO up the chimney.   The mild ones are known as "puff backs". The really big ones, called "boomers", can remove stove parts to other parts of the room.  Hence why stove guys love to see those "Blue Ladies" dancing on top of the firebed - a sure sign that the firebed is safely burning off the CO before it can become a high enough concentration in the stove to be explosive.

 

Paul

Edited July 5, 2019 by PFitz (see edit history)

[Harold]

FWIW, cars have been equipped with CO generators and there is enough oomph to power a car engine.  There were many of these conversions in Germany during WWII.

[chistech]

Put some olive oil along with salt and pepper on in then get your pan good and hot on the stove.Then put the fuel tank in it for 2 minutes then flip to braise each side. If you want to braze it, do what everyone else has said. 😂😂

 

( sorry, couldn’t resist, it was the first thing that popped into my head when I read the post title)

[PFitz]

27 minutes ago, chistech said:

Put some olive oil along with salt and pepper on in then get your pan good and hot on the stove.Then put the fuel tank in it for 2 minutes then flip to braise each side. If you want to braze it, do what everyone else has said. 😂😂

 

( sorry, couldn’t resist, it was the first thing that popped into my head when I read the post title)

 

Oh! How brazen of you  to say such a thing !

 

Paul

[Restorer32]

If CO2 is flammable please explain how CO2 fire extinguishers work. C02 just like CO and oxygen is an accelerant but is not flammable in it's pure state. That is why CO2 is used as a shielding gas when MIG welding. Care to argue about Nitrous Oxide? It is not flammable either.

 

[mike6024]

CO2 is not flammable.I think people were arguing with you because at one point you seemed to say CO was not flammable; but maybe that was a typo of yours.

 

The chemical equation is this:

 

Two CO plus one O2 equals (or reacts to produce) Two CO2

 

2CO + O2  --->  2CO2

 

CO is a product of incomplete combustion. It can be "burned" further by adding more Oxygen.

 

 

[Restorer32]

Depends on your definition of "burn". If you had a tank of pure CO and hooked it up to your torch head you would not be able to light it by itself. If does support combustion and oxidizes to CO2 but I do not believe it burns if by burn you mean it will produce a flame in the absence of any other combustible. 

[Restorer32]

Wood gas, as used to power cars many years ago is produced by burning wood in a closed container. Woodgas consists of hydrogen and CO. The hydrogen burns with a blue flame. The CO supports the burning by providing the necessary oxygen but does not in itself burn.

 

[mike6024]

Yes by "burn" I did not mean you can fuel a torch with CO. I would think you are correct that it cannot be a fuel for a torch. By "burn" I simply meant it can be oxidized further.

 

The chemical terminology is Oxidation-Reduction reaction. You add oxygen to a fuel and get this reaction, and what is called entropy increases, meaning you end up with less chemical energy and more heat.

 

CO can be oxidized further. So in that sense it can serve as a fuel for an oxidation-reduction reaction.

 

So if you want to fill the fuel tank with exhaust gases, which is what I think you initially suggested, that would be a lot of CO2 and maybe a little CO it is OK by me. You would be adding something that has a bit of oxidation potential though.

 

In refineries they use N2, nitrogen gas. When a large tank like a hydrocracker is full of crude oil that needs to be broken down with heat and a catalyst, it is not explosive, because it is full of fuel, and no oxygen or oxidizer. But when they drain it for servicing, they do not let any air in. They backfill with N2 to fill the void space.

 

 

Edited July 6, 2019 by mike6024 (see edit history)

[Restorer32]

So actually we are both correct. Chemically speaking rust is nothing more than a very slow "burning" of steel.

[Restorer32]

Good discussion even if a bit esoteric.

[capngrog]

4 hours ago, Restorer32 said:

If CO2 is flammable please explain how CO2 fire extinguishers work. C02 just like CO and oxygen is an accelerant but is not flammable in it's pure state. That is why CO2 is used as a shielding gas when MIG welding. Care to argue about Nitrous Oxide? It is not flammable either.

 

 

Carbon monoxide is a (very) flammable gas and will combine with free oxygen to form carbon dioxide.  Oxygen gas will not combine with free oxygen, thus not meeting the classic definition of "combustible" or "flammable".  Under ambient conditions, nitrous oxide is, as you stated, not flammable; however under high temperatures (such as in a combustion chamber, it will break down, releasing free oxygen, thus accelerating the combustion process.  We're discussing (not arguing) normally encountered conditions here, not some exotic circumstance such as occurs in "rocket science", for example.  Under conditions encountered by most of us, carbon monoxide is highly flammable, and carbon dioxide is inert.

 

Here's a link to an MSDS for carbon monoxide:   https://www.airgas.com/msds/001014.pdf

 

Cheers,

Grog

[mike6024]

I would say rusting steel generates heat, but not enough that it can be easily measured. When you scratch a stick of magnesium, you get heat and sparks enough to light a camp fire, because the magnesium is oxidizing to magnesium oxide.

 

Oxidation-Reduction reactions are exothermic and result in increased entropy. 2nd law of thermodynamics.

 

When you burn gasoline you get CO2 and Water H2O and heat and higher level of "entropy." So you have gone downhill on the chemical energy scale; in other words chemical energy is converted to heat energy.

 

 

Magnesium Fire Starter

 

Edited July 7, 2019 by mike6024 (see edit history)

[Bloo]

14 hours ago, chistech said:

Put some olive oil along with salt and pepper on in then get your pan good and hot on the stove.Then put the fuel tank in it for 2 minutes then flip to braise each side. If you want to braze it, do what everyone else has said. 😂😂

 

( sorry, couldn’t resist, it was the first thing that popped into my head when I read the post title)

 

I tried to braze a chicken, but I couldn't get it hot enough to melt the brass, it just kept catching on fire. Oh well. My Grandmother used to say "If at first you don't fricassee, fry fry a hen!"

 

[mike6024]

If you filled a tank with CO and O2 in the proper stoichiometric ratio, which would be 2 molecules of CO to every one molecule of O2, and you put a spark to this filled tank, I'd think indeed it would explode. So don't try it.

 

[mike6024]

Braised short ribs!