# Oxy acet



## Hukshawn (Jul 24, 2017)

Heyyyyyy...

So, I did some oxy/acet welding in school on a robot I built (15 years ago...) mainly because that's what the teacher was comfortable with me doing (off class hours). 
And over the years I've come across a few instances where I would have liked a torch to do a project. 
Well, I had one of those said projects come up recently and I made the plunge and leases some bottles. 
The project went well, some cutting, some heating/bending, no brazing just mig welded. 
I bought a set of used regs and a torch kit that came with cutting and a few welding tips. Was a good deal. 
The cutting tip was worn out so I replaced it. In playing with the cutting torch tonight, the torch was popping and going out. Did a quick search and realized it was flashbacking. (I'm aware of this issue and it's dangers but wasn't aware of its causes and etc). Raised the pressure on the regs and my little play test went fine after. The new tips flame is much nicer and straighter than the spray-in-all-directions of the old tip. 
Anyways, what occured to me was, I don't know nearly enough about oxy/acet welding. 

So, I reach out to the community. 
What are your resources, share your knowledge with me. My experience is such that I know how to achieve a good flame for cutting and welding and heating, and can perform all those said operations, however that's pretty much where the knowledge ends. 
The tips, the tricks, the warnings, the be smart and play safe/don't you put that in your mouth-'s, those are what I need...


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## GA Gyro (Jul 24, 2017)

Each of the major manufacturers of torches has some basic stuff online:
Victor
Harris
Uniweld

Another idea would be a local community college course


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## Hukshawn (Jul 24, 2017)

I'm checking those out now.


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## Ulma Doctor (Jul 24, 2017)

i learned welding technology for 2-1/2 years at community college- SMAW and GTAW.
i was welding GMAW, and FCAW during my normal work as an iron worker.
needless to say i lived, breathed, and sweated welding for quite a while 

if your torches don't have them, some anti-flashback valves would be HIGHLY recommended, they will prevent a major catastrophe.
they are installed between the hoses and the torch body and are relatively inexpensive (for a lifesaving device)
use a cart for your bottles, and/or keep them chained up vertically
do not use oil on gauges , fittings, or connections
always wear safety equipment- 
Gloves, Boots, Leathers. Proper Eye Protection for the operation, Welding hood/welding glasses, cotton or wool clothing (no synthetic materials- they leave horrible scars when melted-don't ask how i know that)
watch out for leaded steels, they do not weld very well and can put lead directly into your lungs!
keep a fire extinguisher with you at all times.
if you have the luxury of a spotter, use a set of eyes to watch for things catching fire while you are distracted
if you have light colored eyes, use darker shades in your hood or glasses

a good flame is different for differing applications:
for cutting, you'll want a lot of acetylene- the regulated pressure may be in the neighborhood of 10 psi (dependent of torch size and metal thickness, etc.)
also for cutting, you'll want a lot of oxygen may be in the 35 psi range (dependent on factors noted above)
for brazing and welding,  you'll go with lower pressure of both gasses maybe 5-7 psi acetylene and 10-15 psi oxygen ( heavily dependent on torch size and operation)

my father was a plumber for most of his working career, i learned to sweat pipe together young.
he also showed me how to weld angle iron together back to back without using filler rod- only the parent metal and a half moon pattern with a neutral flame.
it required a lot of patience for a young kid, but i was determined to get it. i used up half a bottle of acetylene and a full bottle of oxygen before i felt proficient.
then my uncle, who was a body and fender guy showed me how to torch weld thin metals with coat hanger filler rod, same principles applied but the work is much faster with filler rod!
sorry for the anecdotes, they have little pertinence but if i have the capacity to learn- so do you! 
it's a lifetime of learning, if you are doing it right!
all the best!


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## FOMOGO (Jul 25, 2017)

Some good advice from the Dr. above. I took a refrigeration welding course in 1970, when I was stationed at NAS Jacksonville at a local community college. If you can gas weld aluminum tubing, you can weld most anything, with a little practice. I find, generally speaking, that right at that point that you first get a clean blue flame is the best place to start. That, and the right sized tip, go a long ways towards a good finished product. Good luck in your quest, I'm sure if you keep at it, you will find  that sweet spot, when things come together. Cheers, Mike


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## Hukshawn (Jul 25, 2017)

Yes, the flashback arresters. They are absolutely on the list. When I got the torch I took it (somewhat) apart to clean and s shocked how much soot was inside the connections...

I think the things the area I'm most lacking is pressures. I have to make a list of the tips I have and maybe make a chart for pressures.


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## Hukshawn (Jul 25, 2017)

For my reference (a notepad...) and for anyone curious. 

Tips 

Cutting - air Liquide 802-2 25mm

Welding AL 703
#0, #1, #2, #4 

Valve Body AL 32140741
cutting body AL 2102 

I'll look these up later. 

The regs are harris, btw.


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## RJSakowski (Jul 25, 2017)

As I recall, acetylene is unstable above 14 psi.  Acetylene is dissolved in acetone and infused in a matrix of an inert filler material.  If an acetylene tank is stored or transported in a horizontal position, it should be allowed sufficient time (at least an hour) for the acetylene/acetone to redistribute in the matrix before using.  If an acetylene tank recessives a sharp blow, a void can occur in the matrix.  The tank should no longer be used.


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## Hukshawn (Jul 25, 2017)

http://www.farwestforge.com/Forum/bsgview.php?photo=136


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## Old junk (Jul 25, 2017)

Practice lots of it.materials like different flames play around and see what works and what doesn't.thats how I learned.at my auto repair shop tanks stay at accet 5 psi oxy 20 works best for me and not wasting fuel.


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## GA Gyro (Jul 25, 2017)

I run a heating and AC company... we have a mini-Oxy/Acy rig on the van...
Generally, I have a #2 tip, and run 3-4# on Acy and 12-15# on Oxy...
Seems to work best using 5% or 15% silver solder rods to 'braze' (bad word) copper to copper or copper to brass.


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## royesses (Jul 25, 2017)

Attached is a short course on ox-acetylene welding and cutting for those who are interested.
 Also read the following safety warning about Copper Acetylides:
Copper, silver and mercury become explosive in contact with acetylene:
Mine Safety and Health Administration    MSHA's Accident Prevention Program
Miner's Tip

Hazards of Acetylene Gas

PDF Version
   Safety Something YOU can live with!
Mine Type: All Mines
Category: General Safety and Maintenance
Accident Busters Photo Acetylene is the most common gas used for fueling cutting torches. When mixed with pure oxygen in a cutting torch assembly, an acetylene flame can reach a temperature of 5700 F. ACETYLENE IS EXTREMELY FLAMMABLE AND EXPLOSIVE. Many users may not be aware of the unique characteristics of acetylene that create special hazards compared to other fuel gases. These hazards include the following:

    Acetylene is chemically unstable which makes it very sensitive to conditions such as excess pressure, excess temperature, static electricity, or mechanical shock. Exposure to any of these conditions can cause it to undergo a violent, explosive decomposition reaction. If this reaction or ignition occurs within the torch base or supply hose it can propagate back into the storage cylinder causing it to explode violently.
    Acetylene is very easy to ignite. In fact, the energy from a static spark capable of igniting acetylene is lower than for any other fuel gas except hydrogen. The static charge developed by walking across a carpet floor on a dry day can be 1700 times greater than that needed to ignite acetylene! When unburned acetylene gas is discharged from a torch, static electricity can be generated at the torch tip. If the tip comes in contact with a ground path, a static spark capable of igniting the gas can occur.
    Acetylene burns at a very fast rate. The very fast burn rate can accelerate the rate at which pressure is generated in an explosion beyond what would occur for other fuels. This makes acetylene explosions more violent than those of other fuels.
Acetylene forms explosive compounds with copper, brass, copper salts, mercury/mercury salts, silver/silver salts and nitric acid. Under no circumstances should acetylene gas come in contact with unalloyed copper, except in a torch. Any contact of acetylene with high-alloyed copper piping will generate copper acetylide, which is very reactive and may result in a violent explosion. Also, an explosion hazard will result if the gas comes into contact with silver bearing materials such as those used in silver-brazed pipeline joints.
    For additional detailed information on the hazards of acetylene, visit: http://www.mshas.gov/alerts/hazardsofacetylene.htm

Issued:    04/19/2002

Roy


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## Ironken (Jul 28, 2017)

Everything has been covered here but this. You may at some point want to use a larger welding tip or even perhaps a heating tip (rosebud). Always keep in mind the 1/7th rule. Your acetylene withdrawal rate cannot exceed 1/7th of your cylinder's volume. Your acetylene cylinder contents can become unstable.

For example, if your rosebud consumes 10cfh of acetylene at the recommended pressure for that tip, you would need an acetylene cylinder with a volume of at least 70cf.


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## Hukshawn (Jul 28, 2017)

Mine are size 22 oxy 23 acet. So about 129 scf.


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