Rod won't melt

JN,

It may be a fine point of semantics, but "welding" is a process by which the parts being joined are melted (fused) together.

No fuel gas alone, is capable of this. And of all the fuel gases on earth, only ONE is capable of this, if, and only if, combined with oxygen in proper proportions: acetylene.

So, what you have is not a welder. It is a propane torch. While capable of soldering (not welding) there is a limit on what it can do, even with solder.

Your problem is that "temperature" and "BTUs" are different things. The instruction sheet is probably correct. Put another way, all matches burn at the same temperature.

But try to boil a gallon of water with a single match...

In other words, you may need TWO or FIVE or ONE HUNDRED $20 dollar torches to provide enough heat (BTUs) to do a given job.

Stated another way: "If at first you don't succeed.... GET A BIGGER TORCH!"

Make sense?

Vern> I bought a $20 simple welder. It uses propane/butane gas. The operating

Thanks for a quick reply. What does BTU stand for?

I still don't get it. How do I know which torch will melt which rod if I look at the specifications? I though 1460 C (2640 F) flame would melt rod rated for 890 C. I read that copper has a melting point at 1083 C.

Could I be doing something wrong. The flame was blue and looked "right".

"British Thermal Units"

Here's another analogy. You could compare BTUs to "amps".

Consider two batteries. One is in a Yugo. Another is in an 18 wheel truck.

They're both "12 volt" batteries. But one kicks out lots more "amps".

Not to be mean, but your $20 torch is likely good only for lighting cigarettes...

If you're serious about welding or even "brazing" which, by the way is really what you're talking about doing with your copper pipe, get an oxyacetylene kit and a small torch.

Then, with the same tanks and regulators, you can get successively bigger torches. Then you can solder, braze, weld, and even cut, a very wide range of metals.

The first error is not comprehending the instructions. Notice it says a working temp of 650C? And your material has a melting temp 240C higher at 890C

Ya dont have enough torch. Those little propane/butane torches are good for ...hum...melting ice? Maybe doing radiator repair..assuming a metal one..

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

British Thermal Units

Ill give you an anology. You are trying to fill a 2000 gallon fish pond in your back yard with a garden hose that will deliver 500 gallons an hour.

So if we do the math..it should be filled in 4 hours, correct? However..the pond leaks at the bottom and it leaks at 300 gallons an hour. The upshot is..while you are gonna get it ALMOST full..it will never get to the top for more than a minute or two.

Metal..radiates heat pretty well..you pump in heat in one end..and it radiates all over the piece...this has the effect of cooling the end you are trying to heat. You are loosing heat nearly as fast as you pump it in.

So what you need to do is put in Shitloads of heat in larger amounts than the metal can radiate it away. That little torch simply doesnt have the massive horsepower to flood the metal with massive amounts of heat to overcome the radiation loss.

In the fishpond analogy at the top..you need a big fire hose rather than a garden hose.

And its not the Size of the flame..but how much heat it produces and the amount it produces. That garden hose..with a spray nozzle on the end..can wet down a wide area..but it will never flood the area. Use a firehose with a wide spray nozzle..and you can flood the area pretty fast.

BTUs is the measure of the amount of heat that a flame or other heat producer actually contains. And propane/butane, unless you use an amplifier. such as Oxygen, will have only a small (relatively speaking) amount of BTUs and even with O2..you need to use a Shitload of well focused flame to overcome the heat leaking away.

People cut steel daily with propane. But they use large speciall designed torches that mix oxygen in, in large amounts, and even then..its still no wheres as hot as O/A

Hope I didnt confuse you too much.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

You can build your own torch and get plenty of heat. Google on " Mike Porter torch " and you will find a book on building your own torch in several sizes.

Second I like the fish pond analogy. The solution is of course to patch the pond liner so the water does not leak as rapidly. With metal that means insulating to prevent heat loss. I use a couple of insulating firebrick. One to put the part on and another behind the part to hold the heat in. Those little porpane torches do work pretty well, but don't supply enough heat for large objects.

Dan

Hydrogene :-)

Nick

"Gunner" wrote: (clip) So what you need to do is put in Shitloads of heat in larger amounts than the metal can radiate it away. (clip) ^^^^^^^^^^^^^^^^ Gunner is right, but let me 'splain it another way. Let's say I am trying to do a job with my oxy-acetylene torch. We all know it has a very high flame temperature--enough to melt damn near anything. But, let's say I put on a very small tip--way too small for the job. Even though the flame temperature is high enough, the work doesn't get hot enough to make the rod melt and flow, so I'm there all day wasting gas and getting nowhere. If I try successively larger tips, I come to the right one, which makes the rod melt and flow. Now if I keep increasing the tip size, I soon find that I am making the work too hot, so it burns or melts, and the job is ruined.

You need a torch whose flame temperature is well above the proper working temperature, and whose capacity gives you CONTROL.

BTU - British Thermal Units

A BTU is very close to a KiloJoule - it being 1.05435 times larger.

A therm is 1.000x10^5 times larger than a BTU.

A ton of TNT is ~39.65 [sounds like inches in a meter... :-) ] larger than a therm.

However I take a difference to Vernon - who is very very good at this stuff.

Given a Propane-Oxygen rig with a welding set (acetylene Vector...) does very well.

It isn't far different from Acetylene and is more stable....

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

Jimmy Neutr>

Several good explanations have been given regarding flame temperature vs the temperature a flame can impart to a workpiece. Small hot flame

• large cold workpiece = warm workpiece.

The short answer is, propane and butane torches are good for soldering but marginal to hopeless for brazing at the temperatures you describe. That's why the guys that make oxy/acetylene torches costing significantly more than $20 are still in business.

The $20 torch was just for testing. I am still not sure which torch I should buy into my set of tools. I am looking for a tool for small jobs around the house. Safety is one concern and ease of use and versatility is another.

Geez, I can't really agree with you here. I have a oxy/acet torch but use a hand held propane torch for sil phos and silver brazing most of the time. You do need to use insulating firebrick around the parts, and the parts can not be huge. But propane is plenty hot enough for brazing. You just have to keep the heat contained.

Dan

OK, I'll stand corrected on that. If the torch is large enough and the work small enough, it can be done. I've read that Ron Reil has brazed cannon balls together with his Reil burner which uses propane and air. (Lots of propane!) Such a torch can be made with a few bux worth of ordinary plumbing fittings and a MIG tip that costs about a buck. Heat up the garage in 5 minutes flat!

But can you sil-phos or silver-braze 1/2" copper pipe with your propane torch? I think the OP mentioned something about copper pipe. Perhaps the new "turbo" MAPP torches can do that, and they're not expensive. $39 at Depot last I looked.

Hydrogene !!!

Is that the gene that gives you water on the knee ???

AWEM

Gunner,

On this part, you're right:

But as to this, I stridently disagree: < Those little propane/butane torches are good

No, the proper use for that torch is lighting cigarettes and perhaps igniting flatulence.

Ice melts by itself.

Vernon

"Vernon" wrote: No, the proper use for that torch is lighting cigarettes and perhaps igniting flatulence. (clip) ^^^^^^^^^^^^^^^^^^^^^ If you're going to use the torch to ignite flatulence, be sure you install an anti-flashback valve first.

Don -

Everyone is looking at the propane torches for fixing water pipes. Solde= r.

I have a 30 gallon Propane tank and the same height Oxygen tank and a Vic= tor set with a propane tip on it.

I burn through steel with it - and melt 3/8" stick of bronze and heat met= al with it.

Cut up to 1/3 faster and save on operating costs with All-States' propane/oxygen cutting torch. One 5-gallon bottle of propane can replace as much as fifteen 100-cubic foot bottles of acetylene. "

" # Automatic handle # Carbureted Cutting Head # Onx Tip # Big Heater w/#2 Tip and Special Mixer. (#1H to # 5H available=97over 1,=

I got the medium Vector set at my local welding supply. Yes, the hoses w= ill go bad, but then I'll replace them with propane set then. The standard Christmas set= is used now.

I changed out the normal tip for a propane tip. A long bent tube - likel= y for better mixing and perhaps pre-heating.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net=

NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

D> >=20

I can and have used sil-phos on 1/2 inch copper pipe with my propane torch..........Or it may have been with my propane torches 8-). I have several that I found at garage sales. On copper pipe you have to preheat the pipe away from where you are going to braze first and then heat the area where you are brazing. I have resorted to using two torches, one to keep the heat from being sucked from the joint. I have not tried 1 inch pipe, and suspect I couldn't manage that size.

Dan

Leo,

What do you th> "Vernon" wrote: No, the proper use for that torch is lighting cigarettes