[Mike]

is there a safe way to weld up a hole in a fuel tank?

cheers
Mike

[shep]

yep, fill it up with water a few times and then get the
apprentice to chuck a match at it to make sure it is ok to weld.

[ball]

Drain and clean the tank really well then purge it with co2.

It can be done but there is always a risk.

I have seen a motorcycle smash repairer do bike tanks by sticking a big hose in the tailpipe of a running car then the other end in the tank and let in run for half an hour or so.

I would still cringe when I saw him wave the oxy torch over the filler of the tank.

[guerd87]

fill it up with water and wel the hole up with the tank still full (if possible, that is if the tank can be sealed so the hole isnt under water)

[Damo]

ball wrote:

Drain and clean the tank really well then purge it with co2.

It can be done but there is always a risk.

I have seen a motorcycle smash repairer do bike tanks by sticking a big hose in the tailpipe of a running car then the other end in the tank and let in run for half an hour or so.

I would still cringe when I saw him wave the oxy torch over the filler of the tank.

As ball said, the proper way is to purge with an inert gas.

The theory is that with no oxygen a fire (and subsequen t explosion) can't occur. I cant remember what flow rate is recommended, but you calc how long to leave it fill (capacity/flow rate), and leave it a little longer just for safety factor. Have the gas flow continue while you weld to ensure all the oxygen is displaced.

I have done a tank repair once before, I filled it with water. I think the water thing is not recommended because water + electricity = potential hazard.

[royce]

is there an inert gas that is heavier than air so it will 'fill' the tank?

[Damo]

royce wrote:

is there an inert gas that is heavier than air so it will 'fill' the tank?

CO2 is heavier than air.

[Gthubba]

Yeah you can buy it from your local BOC or you can try Argon as well

[twitchy]

Just chuck some dry ice in it....... simple.

[ZukChiK]

I took mine to a fabrication place & had it steam cleaned. Cost me about $40 to have it done. I later found out a mate could have done it for free by taking it to his place of work... Damn him!

[TZAR]

twitchy wrote:

Just chuck some dry ice in it....... simple.

expanding on this idea

take out the sender unit and turn the tank upside down. pump a little air in through the pick up so this way any heavier than air hydrocarbon vapours will float out the hole. Do this over night. then turn on its side with the hole ( damage ) to the bottom and the filler and sender hole as high as it can be then drop some dry ice pellets into the tank. this will help purge the tank.

the trouble is the hole will be on the bottom and the you will want the hole to be on top so its easier to weld. this way any heavier than air gases will fall out the filler neck or sender unit hole. Capping these holes is not a good idea to trap the gas in.

also dry ice pellets will cause the metal to be at minus 78.5 c which if heated rapidly and then cooled rapidly will affect the strength of the steel.

[ball]

Gthubba wrote:

Yeah you can buy it from your local BOC or you can try Argon as well

co2 is the go as argon is expensive

[TZAR]

Nitrogen is cheap too and is more effective.

[guerd87]

if you place a cup full of dry ice pellets in the tank submerge them in around a 1L of water, will cause it to break down alot quicker and will give more gas to purge the tank

[zooked]

Flush with water till no fumes then use large sordering iron and solder hole is a lot safer than welding it.

[zooked]

Flush with water till no fumes then use large sordering iron and solder hole is a lot safer than welding it.

[steve]

shep wrote:

yep, fill it up with water a few times and then get the
apprentice to chuck a match at it to make sure it is ok to weld.

yeah too much over analyzation with this gas shit. Just wash it out with water a couple times as shepo said, throw some flames around and you'll be let down because it won't catch fire. then just weld it.

[JrZook]

Just welded up a crack in mine. Rinsed with water and left open in the sun for two days. Threw a match in for precaution, nothing happened, so happy welding.

Dan

[shep]

all i do is fill the tank up with fuel, rub the crack with a rag
to get it really clean and then jam a bit of metal epoxy in the crack.
the stuff i use is called kneedit and it seals and sets no problems.
leaking tank fixed in a few minutes.

[ball]

shep wrote:

all i do is fill the tank up with fuel, rub the crack with a rag
to get it really clean and then jam a bit of metal epoxy in the crack.
the stuff i use is called kneedit and it seals and sets no problems.
leaking tank fixed in a few minutes.

Bush mechanic style

[Pubic]

fill it with argon and purge weld it!

[shep]

ball wrote:

shep wrote:

all i do is fill the tank up with fuel, rub the crack with a rag
to get it really clean and then jam a bit of metal epoxy in the crack.
the stuff i use is called kneedit and it seals and sets no problems.
leaking tank fixed in a few minutes.

Bush mechanic style

keeps the fuel in but.

[ball]

shep wrote:

ball wrote:

shep wrote:

all i do is fill the tank up with fuel, rub the crack with a rag
to get it really clean and then jam a bit of metal epoxy in the crack.
the stuff i use is called kneedit and it seals and sets no problems.
leaking tank fixed in a few minutes.

Bush mechanic style

keeps the fuel in but.

doesn't have to hold it in for long the way your suzi drinks it

[twitchy]

If you are in the bush the good old sunlight soap works as well, rub it into the crack & it will seal it for a few days, long enough to get you home. ( That's if you fellas have any soap... )

[ZukChiK]

twitchy wrote:

( That's if you fellas have any soap... )

I have a feeling none of them wash

[Damo]

ZukChiK wrote:

twitchy wrote:

( That's if you fellas have any soap... )

I have a feeling none of them wash

Cmon, we know you chicks love that manly smell