I can't weld for sh%^. Please help :(

[ReQuieM]

Hey

I have an Oxy-Lpg rig which I originally got to weld up aluminum. I've managed to get that going ok, not great but its defiantly useable. Now I need to weld some steel and I suck big time. I can't seem to get it to flow and anything.

I manage to get it up to about a light yellow (through the glasses) but it wont flow, then it will start to boil quite quickly AND STILL NOT FLOW, until I get on the verge of it popping and blowing hot metal ever where then it flows then pops etc. If I actually manage to get it to flow and join with a dob o boiling rod and joins together fine but then cracks as soon as it cools.

I have to admit I have no idea what I'm doing wrong. I'm working with 1mm strips of sheet apparently they have a zinc plating but I was told they would weld well. I was hoping to weld up some windows in a van this holidays but its looking like I'm way out of my league.

Please help!

[ReQuieM]

Also I tried using a 3n and 8n tip... and have cracked the sh$% at least twice now :P

[Hotfoot]

You've been welding aluminium with oxy/propane? And now you are attempting to weld steel?? I am not aware of anyone doing either, so I'll be watching for answers to see how that's done!:)

[weldgault]

You've been welding aluminium with oxy/propane? And now you are attempting to weld steel?? I am not aware of anyone doing either, so I'll be watching for answers to see how that's done!:)


It cannot be done, because there is nothing in LPG to creat a shield around the molton puddle. Acetylene is it......John

[injun joe]

well you can weld and cut with propane but not nearly as efficiently as acetolene. the heat from the propane isnt nearly as high as acetolene this is what i read in a book that the flame combined with oxygen is about 3800 degrees compared to the 6300 degrees form the acetolene combined with oxygen.so i would switch to acetolene first

[weldgault]

For cutting, that is different, I like propane. It does a good job and will cut thicker material, but it will not weld..................John:) Our subject was welding, not cutting.

[Rocky D]

You need to keep filler metal in the puddle, move along as fast as it will let you...don't allow it to cook too long in one place, and it will weld. Zinc will make it pop, but the filler metal will help you control it.

[Aerometalworker]

EEEEEHHHHHH!!

WRONG :)

Actually it was quite common to weld aluminum with oxy-propane and oxy-Heating Gas. The flux is the shielding from oxygen and does not require an oxygen free atmosphere. Brazing of Steel, stainless, and aluminum also works well

Steel on the other hand.....not good. Since there is no flux, you get lots of oxidation. Now it can be curbed to the point of actually working OK...but setting a non-oxidizing flame is very difficult as there are no real telltale cones. I keep Acet. for steel, Hydrogen for aluminum and propane for heat.

-Aaron

[ReQuieM]

Thanx for the responses guys.

Yep you can weld aluminum with LPG although it takes a long time, hardly time effective. I found pre-heating large pieces was the go, small bits you can freestyle ;)

Ah so there is no hope of welding steel with oxy-lpg then... Just out of interest what about if I used an arc rod (seeing as its covered in flux)?

Looks like I've picked up a cheap (and possible crap! :P ) Tig off ebay instead. Its a 200amp tig inverter DC, out of interest will this do aluminium as well? I remember that aluminum used a different current but I was pretty sure it was DC... If it wont is there a way to suppliment it so that it will? I can list the other specs if needed

The oxy was starting to need some replacement parts and to be honest it was annoying to use. I'm sure Acetylene would have been a smarter move in the first place, but i was told when I brought it that it would do every thing the acetylene would. Typical sales BS i guess.

[ReQuieM]

Oops I just answered my own question. I need AC, yep I'm a D I should of checked first. I'll post this in the TIG section as well but is there a suppliment you can get to change it from dc to ac?