FWIW,
Just about all GM gas tanks (when they used to be steel!) had the fill necks and
most other tubes soldered in. They used natural gas fired torches (ussually
mounted in jigs) to heat the tank and the necks and solder was applied. After
the soldering was done the tank were pressure tested and visually checked for
leaks while underwater and pressurized. The process was very simple. I used to
work at a GM assembly plant. They still visually pressure check the new plastic
tanks under water.
Dave
>>>>>>>>>>>>>>>>>>.
Orintz wrote:
> Hi,
> I have done several repairs on various tanks in the past and have seen one
> fellow have a pretty nasty explosion welding a tank without flushing it out
> first...burns, a few cuts and a ruined set of shorts, also the tank was
> plumped up bad enough to make it a total loss.
> I never tell anyone that I think they should weld/braze a fuel tank for a
> repair as a rule, however I have and if you are going to I would suggest
> that welding or brazing is better than soldering. And yes you use flux for
> brazing. There are other epoxy and fiberglass methods out there that you
> could check into as well.
> As for putting torch to tank I ALWAYS flush them out with water first...not
> just a little but for extended periods, I am talking over an hour with a
> garden hose.After that I empty the tank and let it out in the sun till it's
> dry and give any fuel that might be in a seam or nook a chance to leach out,
> at that time smell the tank and if there is any evidence of fuel repeat the
> watering, (yes I have smelled fuel after an hour of running water thru a
> tank) when there is no more smell of fuel , I then hook up a hose to a
> tailpipe and let exhaust fumes flood the cell for about a half an hour.An
> old timer suggested that to me saying the exhaust would force out any
> combustibles (I often wondered what would happen if your purge vehicle was
> running rich ). Only when I am sure beyond a doubt that there is no fuel or
> vapors in the tank will I light up my torch and begin.Some of the tanks I
> have done have been avgas and some jet fuel as well as auto fuel , perhaps
> some will think I am overcautious, but I would rather be overcautious then
> injured or responsible for injuring others. One thought on the area that has
> the holes, might it be better to replace this rusted are with new metal? Not
> being able to see the area I was just thinking your repair might be in an
> area that is bound to fail again soon, you may be better to cut it out and
> replace...remember that the same safety methods should be used for cutting.
> Just my take on it.
> Orintz
>
> ----- Original Message -----
> From: "Rikk Rogers" <rkltd@swbell.net>
> To: "Mil-Veh2" <mil-veh@uller.skylee.com>; "MVlist" <MVlist@yahoogroups.com>
> Sent: Sunday, June 10, 2001 11:38 AM
> Subject: [MVlist] welding/repair technique question
>
> > I have not yet caught up on this weekend's postings and I am out the door
> > again on another project. But, I need some quick advice. The fuel tank
> on
> > this M38 has a bunch of little holes in the bottom from corrosion. It
> > appears to have rusted from the bottom side up. I am sure I can prime and
> > paint this thing, but the repair of the holes is proving difficult for my
> > meager skills. The question, I guess, is what technique should I be
> using?
> >
> > My first try was with a propane torch and 60/40 solder. However, not
> having
> > any experience at all with filling rough panels or pits, I seemed only to
> > succeed in burning off the flux. My second try is only slightly more
> > successful. I have used a soldering iron designed for stained glass and
> > while it does seem - in some cases - to create a bond, it is not large
> > enough to get the steel hot enough for the solder to stick in most cases.
> >
> > I have no experience in proper braising, so if I go that route, a good
> > outline of the procedure would be appreciated. BTW - does braising use
> > flux? I think it does, but I can't remember. It's been 20 years. Any
> help
> > would be appreciated. I do not want to spend 200-300 dollars on a new
> fuel
> > tank. If anyone has a good take-out cheap I might go that route.
> Greatest
> > thanks in advance. My 5-gallon plastic fuel tank works great, it just
> looks
> > funny tarp-strapped to the back of the M38.
> >
> > Thanks again.
> >
> > Rikk Rogers - RK Lion LTD.
> > 416 S 4th St
> > Ponca City OK. 74601-5335
> > (580)762-3157 rkltd@swbell.net
> > http://home.swbell.net/rkltd/
> > -M35A2- -M38- MVPA -22345-
> >
> >
> >
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> >
> >
> >
>
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This archive was generated by hypermail 2b29 : Thu Jul 05 2001 - 00:40:35 PDT