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welding diesel tanks



My comments about welding fuel tanks came from my professional training as
a welder and my varied experience.
In 1978 as part of my training board vocational instructing I went-on to
training welders, and of course I would not teach beginners to weld fuel
tanks. Apart from the formal health and safety implications we have today,
but such things have to be done in industry, even large non-bunded oil
tanks get patched by welding when a truck bumps into it, in industry they
don't throw it away and build a new one. (They do exist outside UK).
My comment also assumed that we were talking diesel tanks and not petrol,
but even petrol tanks are welded. Even more so when one is out in the
wilderness and a repair has to be done, its often the case that such things
as health and safety inspectors etc are not just round the corner in the
bush! But as someone else wrote, there is always a welder in a bush
village, or in my case a mountian-top village.
I have arc welded tank fittings to boat fuel tanks with fuel in them.
Diesel is quite safe and though smelly is not volatile. As one progresses
with the weld one can hear odd bits of slag dropping into the diesel below
and zizzing. A thin gauge fuel tank in a vehicle will have to be removed,
then the split is usually dented inwards with a ball pein hammer for
bronzewelding. The dent provides a place to make a pool of bronze to make
the seal. Otherwise a mig weld can be accomplished direct. Often in these
circumstances when the fuel is emptied first you then fill the tank with
water usually to overflowing to remove all volatiles - in the case of
petrol - and then empty it slightly to just below the level of the weld.
(A piece of plastic bag held with a rubber band or jubilee clip is all that
is needed to seal the filler neck when the tank is upside down and full of
The residue of water in the tank will be minimal, in fact I think less than
the average condensation that can accumulate over a summer in the bottom
(and subsequently filter water trap). But anyway the filter will trap it on
its way through.
Just remember anything is possible to those who have the skills, walk round
the corner if you wish while the job is being done, but don't discount
anything when it comes to keeping a vehicle moving in remote areas. Forget
the theory and leave it to a practitioner, that's how my 'industry' works
in difficult conditions !
'92 HZJ80 ex UN surplus from Bosnia, now sharing time between Alfold Surrey
and Tring Herts. & happy to be back on my boat where I have some steel
fittings to attach to my central heating oil tank !
Hi Jon
Thanks for the info. May i contribute a few ideas?
By all means take the tank out and away from car. diesel is relatively easy
to repair but the leak needs to face upwards otherwise the weld will not
take very nicely.Clean the edges and scrape paint off. I found soldering
much easier. Do not try and remove dents while in the bush, the material
will just get thinner.
Petrol tanks we used to fill with water but one needs to keep a vent open.(vent
with some long tubing.)In africa you will find in the bush usually arc welding/generator
and soldering, Mic/Mac and alu in cities. The africans also know how to plug
holes, there is a multitude of variations.The plastic thingis
can be epoxied but it won t last. Depending where and when you go the tank
will take battering and plastic is not the ideal material for that.
PS am still waiting for my head nodding doggy?
On 4/23/05, [Email address removed] <[Email address removed]> wrote:
I remember that once I made a hole in a plastic tank. As the hole was
no more than 5mm dia., I pop riveted it and pasted over with epoxy
putty. The problem was sorted for the rest of the vehicle's life.
Roman (London, UK)
'92 HDJ80
Mike wrote...
Thanks Mike, I too could have given the full run-down of the process, and
as we both know, its no big deal to do this. But I was worried that some of
our friends with limited knowledge in this area were discounting welding as
a means of repair as they see heat+ vapour = big bang, when we both know it
does not. By the way, in out of the way areas people (like me even in UK)
use arc plant with carbon rods to bronzeweld too.
Roman, yes, I have done that with other fluids too. I once read somewhere
the relative pressure of a pop rivet and if one can seal it effectively
then its very efficient. But even steam loco boilers were just riveted with
always a few 'sizzlers' that never quite made it !
'92 HZJ80 ex UN surplus from Bosnia, now sharing time between Alfold Surrey
and Tring Herts.