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opt
30-01-2009, 03:56 AM
So my oxy acet set had an unfortunate event with the ground and was pretty much dangerous to use, and I called up a general tool store and I thought i might aswell go all out and buy a new set. Ordered, done and a week goes by and they hadnt sent it out (i live rural australia). Call them up and they tell me its on back order and there waiting for cigweld. fair enough so i keep trying to put anything that needs real welding on hold and at the moment. So i finally got my regulators, torch, hoses and all the gear in the mail today to find out they sent me a OXY/LPG set. Argh! So my questions are is oxy/lpg suitable for brazing of most pipe sizes and general use, I havnt gone out and bought a LPG tank yet, but from my understand is that LPG and acet aren't retrofittable and I cant find any refrigeration specific advice on the subject. I cant really wait another few weeks to get a new set of acetylene gear sent out, and buying a LPG tank is pretty simple from my local gas vendor.

K.R.Iyer
30-01-2009, 05:34 AM
I have seen few technicians in India using LPG instead of Acetylene (for cost advantage and easy availability) and working on systems which use soft tubes. So, the answer is "Yes; one can use it".
My further observations on brazing using LPG are:- (1) The brazing joints are not as clean as done with Oxy-Acetylene, (2) it takes a little longer time to complete the brazing

Brian_UK
30-01-2009, 07:11 AM
Might be worth a read here.... to see the differences.

http://www.aussieweld.com.au/product_pages/oxysafety/oxy1.htm

K.R.Iyer
30-01-2009, 07:45 AM
Thanks Brian! This link gave lot of comparative information to me as well.

opt
30-01-2009, 01:45 PM
well there seems to be no significant reason why lpg is a good gas to weld with, think i might just leave the tools in new condition and try and get a change over. Thanks for the link, good resource.

Quality
30-01-2009, 02:59 PM
I have had certain discusions regarding lpg over acet ultimatley lpg can produce to much hydrocarbons in the outer envelope of the flame which could lead to porosity in the alloy

nike123
30-01-2009, 06:03 PM
Main problem is to find adequate torch handle with correct welding tips for propane/butane. Check page 4 of catolg linked below.
I using regularly oxy/propane set for my service works.
Small service kit like this one with double torch and it braze with silver and ordinary copper phospor rod pipes up to 28mm diameter. For higher diameter problem is no fuel but more is low oxygen capacity of bottle of 2L.
http://farm4.static.flickr.com/3501/3239532602_77e352b30f_o_d.png


This (http://www.gloor.ch/pdf/General_catalogue_en.pdf) is link to catalog.
For larger diameters I using oxy/acetylene set.

nike123
30-01-2009, 06:22 PM
I have had certain discusions regarding lpg over acet ultimatley lpg can produce to much hydrocarbons in the outer envelope of the flame which could lead to porosity in the alloy

Porosity is result of overheating.

Quality
31-01-2009, 03:21 PM
Porosity is result of overheating.
Porosity is a result of spelter oxidization / contamination

Break7
31-01-2009, 04:24 PM
I have used oxy-propane for brazing and silver soldering for a couple of years now. It's like ten times cheaper. The only thing is you can't weld with it. Something to do with the carbon to hydrogen ratio. You can't tell the difference by looking at the braze.It's a little cooler but you just turn up the flame.The flame is longer though.The torch tip should have a counter sinked hole in it because the flame tries to lift off. Once the oxy is turned on the flame stays down. practice setting the flame by putting it on some copper and adjust to carburizing flame. because the flame looks a little different with propane.

Quality
31-01-2009, 05:47 PM
I have used oxy-propane for brazing and silver soldering for a couple of years now. It's like ten times cheaper. The only thing is you can't weld with it. Something to do with the carbon to hydrogen ratio. You can't tell the difference by looking at the braze.It's a little cooler but you just turn up the flame.The flame is longer though.The torch tip should have a counter sinked hole in it because the flame tries to lift off. Once the oxy is turned on the flame stays down. practice setting the flame by putting it on some copper and adjust to carburizing flame. because the flame looks a little different with propane.

Good point that " You can`t weld with it" which you can not. Brazing with it is easily viable;)

narkom
02-02-2009, 10:38 AM
Porosity is a result of spelter oxidization / contamination
Porosity is result of overheating. If overheat the joint your solder starts to boil and you will have porosity.

Quality
02-02-2009, 12:03 PM
Porosity :-
http://www.qaqc-construction.com/systems12.php
This is a welding thread not soldering;)

nike123
02-02-2009, 12:19 PM
Porosity :-
http://www.qaqc-construction.com/systems12.php
This is a welding thread not soldering;)


Argh! So my questions are is oxy/lpg suitable for brazing of most pipe sizes and general use, I havnt gone out and bought a LPG tank yet, but from my understand is that LPG and acet aren't retrofittable and I cant find any refrigeration specific advice on the subject.

It appears that welding is only in header, and rest of OP discussion is about brazing.;)

Quality
02-02-2009, 12:20 PM
:o
My Mistake

nike123
02-02-2009, 12:29 PM
:o
My Mistake

We all here make mistakes. Only those who don't participate here cannot make mistakes.

-Cut philosophy-
:D