Pepper pots (no not Iron Man) and wonderful things ... help please

[BuiltnotBought]

So I was wondering if there is a difference between the pepper pot when using Propane on the gas rig. I currently don't have it plumb in BUT the welding supplier has just sold me a "propane" pepper pot and told me the only difference is the thread type. So I took it and it is, as I thought, exactly the same thread as the acet' (I can't spell the bloody word) touch I have. However when I used it all that happened is it blew the middle of the pepper pot out after going out and reigniting a few times.

From looking at it, it would seem like the soot from the acet' has built up inside the pepper pot and caused it to heat up and blow through.
Anyone help would be greatly appreciated.

And does anyone know if I use heavy argoshied to weld thinner material will it matter? Or is it just wasteful??
I am lead to believe heavy is for +10mm.

Cheers guys and gals


Slash

 

[pedrobedro]

Argoshield heavy is just higher co2 content. You can weld with pure co2 if you want but more co2 gives more spatter you'll have to change your settings a bit to suit different gas. You can get universal which is between light and heavy and is a reasonable compromise. There's no wasteful aspect you will only use the same amount of shielding gas if you leave the regulator alone. Acetylene burns a lot hotter than propane and the tips are made to accommodate this.

 

[rikrobson]

There is more heat in a propane flame, it just at a different point. Its at the tip of the inner cone. The reason prople dont like cutting with it is that the torch needs to be further away inlike acetelyne which has its heat in the cone and therefore can cut close to the burner.

 

[pedrobedro]

Oxy acetylene gives 3,400° C and oxy propane 2,200° C according to the info we were given at the foundry when I worked there. We used to use oxy propane to cut 12" metal heads off castings and the pepper pots we used were different design to acetylene tips with larger square holes.

 

[rikrobson]

oxy propane is 2800C but that the temp. there is more heat in the flame overall.

 

[Maker]

Acetylene has a higher flame temperature, propane has more energy in it's flame (higher BTU) so it's more suitable for heating large parts. I believe propane is favoured for cutting thicker sections.

 

[BuiltnotBought]

Maker,

You say propane has more energy in it'd flame, does this mean that it causes a quicker heating of an area? Though surely a temp 1200 degrees higher will heat and area as quickly or quicker would it not?
I have no idea and there seems to be mixed opinions.

Thanks for the input guys

 

[rikrobson]

Its all about transfer of energy. Temerature is a symptom of the energy put into an object.

 

[Maker]

The heat of combustion of acetylene is -1309.5 kJ/mol, propane is –2202.0 kJ/mol.
Also, if you look at the reaction stoichiometry, a propane molecule has three carbon atoms and eight hydrogen atoms, this means it needs five oxygen molecules to burn. Acetylene only has two hydrogens and two carbons which means it needs 2.5 oxygen molecules to burn.

TL;DR ; Propane uses more oxygen.