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Old 09-10-2017, 11:14 PM
crystallographic crystallographic is offline
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Default Oxy-fuel welding with PROPANE

Welding aluminum with oxy-propane is not a big deal.

You need a fuel reg to fit the propane can and some "T" grade hoses that do not deteriorate when exposed to propane, natgas, chemtane, chemolene, propylene etc. "alt fuel" gases.

P1040178.jpg
P1040180 copy.jpg
Note: the oxy bottle is not chained to a post or secured to a cart - so is NOT USABLE unless so secured. Photo is only a demo of what the set may look like.

You can use an oxy-fuel torch and tips and there is no explosive danger mixing one fuel gas with another through the same hose as there is with hydrogen. There are special "alt fuel" propane tips available for some torches, like we carry for the Meco Midget. Instead of one central flame there is a "ring of fire" around a smaller central flame, giving more BTU's into the melt.
P1040168.jpg
N tip on left (oxy-acet) and OX tip on right (oxy-alt fuels).
Flame comparison:
P1040218 copy.jpg
#2 N tip on Meco Midget, using oxy-propane

P1040207 ox copy.jpg
#2 OX tip on Meco Midget - with gas pressures set the same as with the N tip, above, for comparison, using oxy-propane

Use the same sized acet tip for O/P (or maybe one size larger) if you are already welding aluminum with O/A, and want to change over.

Bear in mind that finding the neutral flame is difficult with O/P as there is no defined sharpness of the flame achieved by adding oxygen. The flame cone either gets longer or shorter by twiddling the knobs, so I just do a weld test on an aluminum coupon while adjusting the flame.

Use a really good flux as the propane leaves some smut that the flux is required to carry off during the weld. I use our Super Premium AGW flux. (AGW= aluminum gas welding)
Flux the rod and maybe also the top surface of your joint.

Have at it and see what you get. Torch handling, angle to the metal, cone distance from the work are all the same as O/A.
P1150602 propane copy.jpg
P1150604 propane root copy.jpg

You will have a larger noisier flame for the same weld on the same material as you will with O/A,
using the same torch and tip, as the O/P has less thermal output than does the O/A, because acetylene is a triple-bonded hydrocarbon and the rest of the fuel gases are only double-bonded. Each bond breaks during combustion to release a certain amount of thermal energy, so you have 2/3 energy compared to 3/3 energy output.

Practice, practice, practice, and mark your coupons 1,2,3,4 ... etc.
Then compare your results.
Good luck,
__________________
Kent

http://www.tinmantech.com

"All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919.

Last edited by crystallographic; 09-10-2017 at 11:31 PM.
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