Rate of O/A usage when cutting/welding?

[Gale Hawkins]

Tonight I purchased a set of O/A gauges and a torch. I did a little brazing in shop forty years ago so I have no experience.

I have 20/10 O/A tanks and a tote coming for a portable set up that I can pack anywhere. If cutting only with these will it be good for 15 minutes, 1 hour, etc? What if welding/heating only?

To stay around 50 pounds per tank I am looking at 80 cf for O and 75 cf for A. I was thinking 40 cf for acetylene then noticed the fill price was on $4 more for 35 cf more so it will be good to not have to haul the acetylene tank back exept every other time perhaps.

Is there a rule of thumb for O and A cf usage for each type of torch usage?

Thanks

 

[yomax4]

For Cutting, Basicly you can get away with 20# O2 and 8# Acet. Adjust up or down depending on thickness. Also be sure to use the correct tip size for the job. This can add or cost you gas. You can go on the Victor Website and download tip and pressure charts for the fuel gas you want to use.
Good Luck..

 

[Gale Hawkins]

Thanks for the tip on the Victor site and I will go there. I bought it in part due to the guy reviewing the HF set and that Victor's tips fit it.

I have a lot to learn but did pick up Hayes Techbook on welding at HF yesterday and it is great for someone at my level. Gas welding/cutting set can cover more shop needs to some degree more than any of the other tools on the market today.

 

[yomax4]

If needed, I can send you a Victor Hand Book on Cutting, Welding and Safety. Ijust need an address. You need to buy Flash Arrestors if the After market set does not have them. ( Victor has them Built in.):thumbsup:

 

[mjncad]

I seem to recall that acetylene can only be drawn down at the rate of 1/7 of the bottle capacity per hour. Depending on how much cutting/heating you plan to do, the Porta-Torch outfits may be fine, or they may be too small for your needs.

If anyone has further or correct information, please chime in.

 

[Gale Hawkins]

I seem to recall that acetylene can only be drawn down at the rate of 1/7 of the bottle capacity per hour. Depending on how much cutting/heating you plan to do, the Porta-Torch outfits may be fine, or they may be too small for your needs.

If anyone has further or correct information, please chime in.

That is interesting. Due to little cost difference for gas I expect I will go with O/80cf and A/75cf for most of my work keeping it down to about 50 pounds per bottle yet still a good amount for hobby use.

I will see if Hayes addresses that subject.

 

[paulinkansas]

A few months ago I bought an 80 cf Oxy and 75 cf Acet tank to go with a new Harris type outfit. The only times I've had any issues is when I was heating up a 1/4" x 4" x 8" piece of flat metal to pound flush around a round steel tube (look at my old post for building a boom pole). After 10~15 minutes with a rose bud tip, my flame started to turn orangle. That's acetylene burning (I think).

But other than that, the 80 and 75 cf tank fulfill 99% of my purposes. Last week I had to load them in my truck to cut off some laundry line posts flush with the ground. I wouldn't much like lifting heavier tanks.

 

[yomax4]

1/7th draw is correct. When your flame starts to turn Orange, You are burning Acetone. Stop right there or you will have acetone in your hose and regulators and it will gum things up. If you have cheapo chinese or other after market brand equipment, It's not repairable and you will have to junk it out..Smith or Victor is cleanable and repairable. No orange flame...

 

[Gale Hawkins]

1/7th draw is correct. When your flame starts to turn Orange, You are burning Acetone. Stop right there or you will have acetone in your hose and regulators and it will gum things up. If you have cheapo chinese or other after market brand equipment, It's not repairable and you will have to junk it out..Smith or Victor is cleanable and repairable. No orange flame...

yomax4 thanks for that info. Do you have any idea how long it will take for more acetylene to leach out of the acetone so one can go back to work?

 

[yomax4]

If you lay an acetylene tank down..You have to leave it stand up for the same amount of time before you use it to be sure not to get Acetone in your hose or regulator. Most times when you use a Rosebud or cut with small tanks, You will get a little acetone in your your hose. Just be mindful that it will wreck your regulator.. If you use your tank hard or if it is sub-zero temp, You can wait 4-5 hours and more Acetylene will leech out of the firebrick type core in the tank. Dont turn in your Empty tank too soon!!:thumbsup: