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Posted by Kerry on July 4, 2008, 7:29 am
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>> "Maxwell" wrote: (clip) after just a few seconds of welding, I got an
>> extremely hard
>> > POP from the combustion gasses on the inside. It bloated the metal pan,
>> > and could have been very dangerous. (clip)
>> ^^^^^^^^^^^^^^^^^^^
>> I know of a welding shop that welds gas tanks after running the exhaust
>> from a small engine into the tank for an hour or so. Another idea might
>> be to shove in several handfulls of dry ice. The CO2 will force
>> virtually all the air out. CO2 is heavier than air, so if any air
>> remains, it would not be at the bottom.
>
> Hum. Maybe you could just fill it up with Argon (heaver than air) (or
> 75/25) and get the same effect??? I'd trust a hose from an Argon tank to
> correctly remove the O2 from the tank before I'd try a stunt like dry ice
> or engine exhaust. Shit, a 2 stroke mixes the combustible fuel with the
> incoming air and pumps some of it out the exhaust on every cycle. Fill
> your gas tank with the exhaust from a 2 stroke and you would be asking for
> trouble when you started to weld. I wouldn't try anything like that
> without the correct knowledge of all the chemistry and risks and the
> correct tools like maybe an O2 meter at hand to verify what was in the
> tank.
>
> Checking a page on the specific gravity of gases, I see some nice gases
> like Butane, Propane, ozone and nitrous oxide are all heaver than Argon
> and
> CO2. Yeah, that would be nice. Push out the O2 but leave the tank full
> of
> butane, propane, ozone and nitrous oxide (close cousin to nitro in
> chemical
> make up). I don't know if O2 in those forms can help the butane burn
> under
> heat, but I wouldn't be the one to bet my life it couldn't.
>
UH, Curt, nitrous oxide is a catalyst that aids in combustion. Ask any
hot rodder about "nitrous" and their eyes glaze over as they tell you all
about their set up.
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Posted by Private on July 4, 2008, 1:13 pm
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>
> Personally, I wouldn't go anywhere near a welding job and tanks of highly
> combustible material. :) I'll let the "real" welders do that crap.
It only takes a few hours to learn how to light a torch or to strike an arc
and run a bead. It takes the rest of your life to learn WHEN to do these
things.
The road to becoming a 'real' welder is filled with customers who want you
to do a quick and dirty (cheap) repair using dangerous procedures which they
claim some 'good old' welders do all the time. These customers always claim
to be knowledgeable and experienced themselves, but always want you to be
the one to do the job and to accept the risk (and liability) and to do these
dangerous jobs for very little cost.
The OP of this thread seems to be willing to settle for a poor quality weld
(that will be severely contaminated by oil) in order to 'save' a couple of
hours of mechanical work to remove the pan, and clean and weld it properly.
The oil contaminated weld will probably fail and may cause further (possibly
severe) damage. Any 'real' welder that attempted this job will of course be
blamed for any failure or further damage or accident.
He also proposes to do this 'welding work on a closed container that has
held combustible material', in an overhead position, on a hoist, inside a
(probably combustible) building, which probably contains other combustible
products, and without draining and removing the fuel tank from the vehicle.
He is also proposing to expose his probably untrained wife who will probably
not be wearing proper personal protective equipment suitable for fighting
fire in an enclosed space.
One should always think about how their actions will appear in the accident
report and on the evening news.
If the vehicle is not worth a proper repair then any of the sealers or epoxy
products made for sealing gas tanks are a better alternative for 'a quick
and dirty' repair.
Fire or explosion is a serious risk every time we do any welding, and safety
must be the first and most important consideration anytime we undertake any
welding job.
Good luck, YMMV
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Posted by Tom M on July 4, 2008, 2:28 pm
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>
>>
>> Personally, I wouldn't go anywhere near a welding job and tanks of highly
>> combustible material. :) I'll let the "real" welders do that crap.
>
>
> It only takes a few hours to learn how to light a torch or to strike an
> arc and run a bead. It takes the rest of your life to learn WHEN to do
> these things.
>
> The road to becoming a 'real' welder is filled with customers who want you
> to do a quick and dirty (cheap) repair using dangerous procedures which
> they claim some 'good old' welders do all the time. These customers
> always claim to be knowledgeable and experienced themselves, but always
> want you to be the one to do the job and to accept the risk (and
> liability) and to do these dangerous jobs for very little cost.
>
> The OP of this thread seems to be willing to settle for a poor quality
> weld (that will be severely contaminated by oil) in order to 'save' a
> couple of hours of mechanical work to remove the pan, and clean and weld
> it properly. The oil contaminated weld will probably fail and may cause
> further (possibly severe) damage. Any 'real' welder that attempted this
> job will of course be blamed for any failure or further damage or
> accident.
>
> He also proposes to do this 'welding work on a closed container that has
> held combustible material', in an overhead position, on a hoist, inside a
> (probably combustible) building, which probably contains other combustible
> products, and without draining and removing the fuel tank from the
> vehicle. He is also proposing to expose his probably untrained wife who
> will probably not be wearing proper personal protective equipment suitable
> for fighting fire in an enclosed space.
>
> One should always think about how their actions will appear in the
> accident report and on the evening news.
>
> If the vehicle is not worth a proper repair then any of the sealers or
> epoxy products made for sealing gas tanks are a better alternative for 'a
> quick and dirty' repair.
>
> Fire or explosion is a serious risk every time we do any welding, and
> safety must be the first and most important consideration anytime we
> undertake any welding job.
>
> Good luck, YMMV
>
Fine words of wisdom.
happy 4th!
Tom
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Posted by RoyJ on July 3, 2008, 9:33 pm
Please log in for more thread options Sounds like a fatigue crack near the weld area. I prefer to braze this
type of problem where you have sheet metal and cracks but a good weld is
acceptable. Biggest problem is that no matter what you do, the heat from
the weld will liquify the oil and let it drain down into the weld area.
Yields crappy welds, not to mention the fun of hydrocarbons on red hot
metal.
You may get by with the wire feed on the car but a permanent fix
involves pulling the pan. :(
Ivan Vegvary wrote:
> Finally found that my oil leak (replaced the drain plug gasket and oil 5
> times) problem is a hairline crack in the oil pan immediately adjacent to
> the drain plug.
> The plug threads into a thickened (re-enforced) area of the pan and
> immediately at the edge of this thickened area starts a hairline crack that
> radiates outward for about 3/8 th of an inch. It is possible that the
> manufacturer welded this thickened area into the pan and the weld junction
> is either failing are developing a stress crack.
>
> I propose to clean the area with a wire wheel and then hit it with the wire
> feed welder. Ground strap will be within a few inches, however I will
> disconnect the battery just in case. Wife will stand by with a huge fire
> extinguisher. Car is up on a hoist.
>
> Removing the pan is the other alternative, but lots of exhaust pipe and
> cross bracing in the way. Probably about 2 hours work.
>
> All comments, suggestions, warnings appreciated.
>
> Ivan Vegvary
>
>
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Posted by Steven Saunderson on July 4, 2008, 4:45 am
Please log in for more thread options wrote:
> I propose to clean the area with a wire wheel and then hit it with the wire
> feed welder. Ground strap will be within a few inches, however I will
> disconnect the battery just in case. Wife will stand by with a huge fire
> extinguisher. Car is up on a hoist.
This might sound crazy but why not try to soft solder the crack with a
big electric soldering iron ? It should be strong enough to seal the
crack and doesn't involve a temperature that can ignite anything.
I soft solder spouts on tins full of spray paint and have never had a
problem.
--
Steven
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>> extremely hard