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I Forge Iron

how do the old blow torches work


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I have one that I use. First empty the tank if it has anything in it and rinse it out well with a little gasoline.  The pump on most of them can be removed with a wrench. Usually the leather seal on the pump is dried out. If it's not too bad you can soak it with a little light oil and it will swell up and work. If not you may have to make a new one. I took the valve and needle apart and cleaned them up on mine. They work just like an old Coleman camp stove. Fill the tank up about 2/3 full of unleaded gasoline and pressurize the tank with the hand pump. TAKE IT OUTSIDE BEFORE YOU TRY TO LIGHT IT!

On mine there is a little trough under the burner/valve assembly. Open the valve and let a little gas drip into this reservoir and light it, carefully! The fuel burning in this trough helps preheat the burner to atomize the fuel. Slowly open the valve and let it burn in a safe direction as it heats up. As it heats up it will turn from a yellow to a blue flame as the preheat fuel burns up. They are kind of scary the first time you use them. I like to keep a fire extinguisher close by. You might have to add pressure to the tank after it burns a little while. They usually have a little bracket on top to support an old fashioned copper solder iron while it is heating. I used mine a while back to heat my irons while I soldered a gutter trough together on a job. You use two irons, keeping one heating on the torch while you use the other. 

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Be sure to do a proper leak down test before you fire one of these things up. Finding a leak by way of ignition while you`re holding it or working in close proximity to it can be a bit more excitement than most folks are prepared for. :o

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  • 5 months later...

INHO, those things were dangerous when they were new, which is why they developed modern soldering torches. Polish it up and put it on a display shelf. It will do its best and safest work there. However, IF you decide to ignore warnings, at least take it completely apart and rebuild it first making sure all moving parts move freely (pump and shutoff valve) and all parts that shouldn't move (everything else that doesn't move i, e. threaded joints) doesn't. Replace the old leather plunger. One reason they are dangerous is they can leak at many places and as the fuel is under pressure, the last thing you want is a fine mist of gasoline near an open flame. That is how the work but the mist should only come out the nozzle. Not the pump or any threaded fitting. This is only a couple things that can go wrong, but when they do, its hard to reverse quickly. I wanted to post some example links but the ones I found had language not allowed here but just Google "gasoline torch dangers"

My 2¢

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Mine sits on display in the garage.  I'm sure it'd be interesting to restore and light, but after an experience with a grease fire long ago and what I've read onlin,e that's were it's going to stay.  Tempting to disable it somehow to make sure anyone it might get passed down to does something dumb with it.  When I first inherited it, I was tempted to do something with it.

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  • 5 years later...

My Dad had one of these. He used it to heat up solder in a little cup made of what looked like 1 inch or 3/4 inch pipe. The cup had a steel handle with wood over the steel to insulate you from the heat. The cup was filled with solder. When joining two wires you twist them together then dip them in the molten solder. It was a good idea to keep some rosin to dip the wire in before you dipped it into the molten solder. The heat from the solder in the cup made the joint very smooth and strong. The blow torch was kept in a central area away from flammables and the solder cup heated periodically as you were joining wires. This was before the twist on connectors we use today were common. The joint was allowed to cool then wrapped securely in electrical tape to prevent any chance of shorting. I imagine the joints were a lot stronger and less prone to thermal loosening than todays twist on connectors. It did require vigilance to make sure the torch was always pointed in a safe direction.

And do I make joints like that now a days?  Nope, I use the twist on connectors. If for some reason I am asking a wire to perform close to its specs I might twist the leads, solder them with a soldering gun, then put a twist cap on. That is fairly rare though. 

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  • 9 months later...
On 8/8/2019 at 7:48 PM, dzimmerm said:

 I imagine the joints were a lot stronger and less prone to thermal loosening than todays twist on connectors.

That's a logical conclusion that overlooks a few things.  The last wiring system in the U.S. to allow soldered connections was knob and tube.  The insulation was cotton and the entire assembly relied on free-air and physical distance for safety.  Free air was vital to keeping the wire insulation from breaking down.  This is an especially big deal for old home owners who think they can hire a blown-in insulation contractor without paying an electrician to remove, disconnect, and replace all the knob and tube wiring in the exterior walls.

However, that doesn't explain why solderless connectors are a code requirement.  Lightning strikes melt out the solder in the electrical system.  Now you might be thinking that this is where all that twisting makes a difference.  Here's the thing.  The twisting does hold things together, but there will be points that arc afterwards.  Those arcs eventually build to where they're a source of ignition.  A wirenut uses a cutting spring to bind the conductors.  It expands and contracts with the  conductors.  The cap on the wirenut is made out of self-extinguishing, low smoke plastic.  Some wirenuts require the conductors to be twisted together before installation, others don't.  Most electricians prefer to twist the wires before installing the wirenut.  That provides a more robust connection.  For what it's worth, wirenuts have to support 14lbs to be UL listed as that's the average weight of a light fixture.

With all that said, I think wirenuts are not the best choice for anything other than clean, dry, immobile and thermally consistent terminations. Especially with stranded wire.  Stranded wire really benefits from crimp or lug-type terminations.  

 

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On 10/11/2019 at 9:36 PM, jlpservicesinc said:

I used to have several.  they worked very well. 

I agree with the suggestion to polish and display, then buy a propane one :)

As for jets for kero or petrol ... no difference. with kero the torch goes whoom. with petrol it goes WHOOOOOM :)

Actually we used to mix kero and petrol 50/50 when agri fuel for the old Fordson stopped being available. It was the best to light the Petromax :)

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On 8/8/2019 at 9:48 PM, dzimmerm said:

If for some reason I am asking a wire to perform close to its specs I might twist the leads, solder them with a soldering gun, then put a twist cap on. That is fairly rare though. 

I would stop doing that, its not code in most places.   Shrink wrap over a crimp is a better choice

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Rockstar;

We dropped our offer on an older (1930s) house in Cheyenne, WY a couple of years ago when I crawled up into the attic and found live knob and tube wiring buried in the blown in insulation.  (Also, the furnace had been installed in 1959 and was putting out carbon monoxide which the inspector had to red tag.)

"By hammer and hand all arts do stand."

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These blow torches were actually designed for use with Soldering irons of the old fashioned type and were the replacements for many a charcoal heater for soldering irons.. 

The top grooves and the hook were to hold the long copper soldering irons and offer some adjustability with the ability to angle the soldering rod up or down some. 

The main 1 I used would have no problem getting a thin metal sheet (16 Gauge) red hot.   

Wish I still owned 1..   When I walked away from the shop the ones i owned went to scrap. 

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As a young man I worked as a silversmith and in the shop I worked in we used Prestolite acetylene air mix torches. Handpiece to hose, to regulator, to tank. Sweet. Then worked in a hippy jewelry shop that used those handheld tank, propane torches for silver soldering. Gads! How I hated those things! Clumsy heavy and only good for peeling paint. I found a craft supplier that carried a handpiece torch with a selection of tips and a 6 foot hose that mounted to those disposable tanks. I would tape that tank to my bench leg and work all day without near the fatigue hefting that portable torch would cause. I was just getting fussy, I guess as I remember having to use one of those gasoline torches regularly once upon a time.


Man jumps from an airplane has problems with his parachute and is fumbling with it. As he falls, a man passes him going up. He hollers to the man, “know anything about parachutes?” “ No!” Says the man, “know anything about Coleman stoves?” This is BP: before propane.

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