PDA

View Full Version : Cheap welding


June 24th 09, 04:41 PM
In keeping with Bob's promotion of "flying on the cheap" I offer the
following:

It is pretty obvious that this is a cheap way of cutting metal, but
has anyone run across a way of using this technology to weld? If so
it might open up more options for the impoverished home builder.

http://www.metacafe.com/watch/1313067/easy_made_fire_for_forge_and_weld_by_teaybkk/
(kind of long and drug out but a very simple set up and build able by
just about anyone)


http://www.youtube.com/watch?v=YWAnv3r0CSw
=======================
Leon McAtee

Morgans[_7_]
June 24th 09, 10:17 PM
> wrote in message
...
> In keeping with Bob's promotion of "flying on the cheap" I offer the
> following:
>
> It is pretty obvious that this is a cheap way of cutting metal, but
> has anyone run across a way of using this technology to weld? If so
> it might open up more options for the impoverished home builder.
>
> http://www.metacafe.com/watch/1313067/easy_made_fire_for_forge_and_weld_by_teaybkk/
> (kind of long and drug out but a very simple set up and build able by
> just about anyone)

I can't imagine that this is anything other than a hoax. What is the fuel,
why are there two lines to the torch, with only one hose hooked to it, how
does that small movement by the bellows produce such a large and even flame,
and the list of questions could go on and on.
--
Jim in NC

Bob
June 25th 09, 12:34 AM
Dear Leon,

Gasoline 'burners' have been around since the late 1800. I think they
need pure oxygen to generate a flame that is SMALL ENOUGH for a task
as intricate as welding thin-wall, small diameter steel tubing.
Unfortunately, the gas generator has a habit of exploding as the
volume of gasoline falls and the amount of the tar-like residues
increases. I don't know why this is so, I'm going on information
heard when I was a kid. That is: gasoline 'burners' are bad whereas
oxy/acetylene are good.

Personally, if I were stuck in a Third World Country and had only a
gasoline burner to weld with, I'd probably try it... but there are a
lot of other methods I'd try first.

-R.S.Hoover

Peter Dohm
June 25th 09, 01:41 AM
"Bob" > wrote in message
...
> Dear Leon,
>
> Gasoline 'burners' have been around since the late 1800. I think they
> need pure oxygen to generate a flame that is SMALL ENOUGH for a task
> as intricate as welding thin-wall, small diameter steel tubing.
> Unfortunately, the gas generator has a habit of exploding as the
> volume of gasoline falls and the amount of the tar-like residues
> increases. I don't know why this is so, I'm going on information
> heard when I was a kid. That is: gasoline 'burners' are bad whereas
> oxy/acetylene are good.
>
> Personally, if I were stuck in a Third World Country and had only a
> gasoline burner to weld with, I'd probably try it... but there are a
> lot of other methods I'd try first.
>
> -R.S.Hoover
>
>
>
Well, I have even less than no experience, but it looks like oxigen could
easily be introduced along with the fuel--especially as the fuel supply
nears exhaustion--and that is a VERY bad thing.

Peter

Capt. Geoffrey Thorpe
June 25th 09, 01:49 AM
"Morgans" > wrote in message
...
<...>
> I can't imagine that this is anything other than a hoax. What is the
> fuel, why are there two lines to the torch, with only one hose hooked to
> it, how does that small movement by the bellows produce such a large and
> even flame, and the list of questions could go on and on.
> --

The air goes from the bellows (one hose) bubbles through the gasoline,
picking up fumes, then goes the torch.

Control would be a bit of a problem - you can't control the mix.

A spark around the glass jar, or burning through the plastic tubing would
result in what some would call an "explosion"

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate

bod43
June 25th 09, 03:46 AM
On 25 June, 01:41, "Peter Dohm" > wrote:
> "Bob" > wrote in message
>
> ...
>
> > Dear Leon,
>
> > Gasoline 'burners' have been around since the late 1800. *I think they
> > need pure oxygen to generate a flame that is SMALL ENOUGH for a task
> > as intricate as welding thin-wall, small diameter steel tubing.
> > Unfortunately, *the gas generator has a habit of exploding as the
> > volume of gasoline falls and the amount of the tar-like residues
> > increases. *I don't know why this is so, I'm going on information
> > heard when I was a kid. *That is: *gasoline 'burners' are bad whereas
> > oxy/acetylene are good.
>
> > Personally, if I were stuck in a Third World Country and had only a
> > gasoline burner to weld with, I'd probably try it... but there are a
> > lot of other methods I'd try first.
>
> > -R.S.Hoover
>
> Well, I have even less than no experience, but it looks like oxigen could
> easily be introduced along with the fuel--especially as the fuel supply
> nears exhaustion--and that is a VERY bad thing.
>
> Peter

I have not even viewed the links, however I would
suspect that -

The absolute last thing in aviation that anyone should
consider doing in a way that deviates from established
practise is welding an airframe.

While welding might appear simple and obvious I have
the idea that this appearance is not the whole and
complete truth. There is a *lot* of chemistry and
metalurgy in the act of welding. The cost of a few
cylinders of welding gas is an insignificant element in
the cost of producing a metal aeroplane. If you can't
afford it use wood.

:-)

Bob
June 25th 09, 04:09 AM
On Jun 24, 8:41*am, "
> wrote:
> It is pretty obvious that this is a cheap way of cutting metal, but
> has anyone run across a way of using this technology to weld? *If so
> it might open up more options for the impoverished home builder.
>------------------------------------------------------------------------------------------------------

Dear Leon (and the Group),

This causes me to wonder: Where would the thin-walled steel tubing
come from? And, what would it be used for? (within the context of
building on the cheap)

First guess would be bicycle frames as a source of tubing, followed
by EMT.

Second point would be it's use, which would probably be for an engine
mount... perhaps for a pylon. Farther down the list would be landing
gear. Dead last would be a fuselage.

Steel tubing offers the best ratio of strength to weight with the
assumption of welded joints. However, we now have hyper-eutectic
brazing LIQUIDS that are stronger than a mild steel weldment (but not
by much). The tricky bit is that the bicycle tubes are joined using
swaged fittings. The tubing and the fitting are PAINTED with the high-
strength brazing compound (nickle-silver, etc. ) which is then brought
to a red heat and allowed to cool.

As a point of interest neither the VP nor the Teenie Two uses a
conventional engine mount. Both of these designs require welding; the
VP on its wing struts and joy-stick, the T2 on its landing gear, joy-
stick, aileron controls and rudder bar. All of these welds can be
replaced with brazed joints although brazing is usually not accepted
by the CAA because of its historic propensity for cracking. The fact
this is not a problem with modern eutectic brazing materials is of no
interest to the CAA since the people who make the brazing material
have not bothered to have the material tested to CAA standards due to
the lack of a potential aviation market. (The fact high-strength
braze has been used on nuclear subs and the Saturn V rocket, is of
little interest to the CAA (various agencies, depending on which
country we're talking about.) )

I think the point here is that the principle of building on the cheap
tends to avoid welding wherever possible, which raises the possibility
of replacing welded components with riveted, or possibly laminated-
composite, components, such as the engine mount. The other
consideration is to use components that do not require any welding at
all, such as a fixed landing gear leg.

Indeed, if we wanted to get into a useful area of experimentation, the
testing of brazed landing gear components compared to welded
components would seem to be a worth-while area of study. I mention
this here because a gasoline torch does perfectly well for brazing,
although because of safety issues I would prefer to use my tried &
true Naphtha-fueled, solid brass blow torch. (In fact, you need a
couple of these things when gas-welding thick-walled tubing of large
diameter. Such torches are needed to keep the back-side of the joint
NEAR welding temperature when you are welding on the front-side. Of
course, if the weld is for something other than aviation, such as a
dune buggy, trailer frame or whatever, a MIG'er will be more
practical.

As for gasoline torches, one of the best is the fuel tank of a junked
car :-)

-R.S.Hoover

Google