help with a new tool

By robjesse Date 12-05-2005 23:31

I just bought the port a torch from lincoln. The descriptions says this Contains all the quality equipment needed for cutting, welding and brazing in a rugged molded plastic carrying case. The outfit is designed to carry one MC acetylene cylinder and one 20 cu. ft. oxygen cylinder. As supplied, the outfit is capable of cutting to 1" and welding to 1/16". Can cut to 4" and weld to 1/2" with larger tips and acetylene cylinders.

Does this mean that I need to purchase a bigger acetylene cylinder if I want to weld or cut larger material? Why is this? If that is true then what material thickness is the cutoff for when I need to get a bigger cylinder? I quess it gets quite complicated.

Also when it says that the materials supplied can only weld to 1/16" and cut to 1" are these numbers total accurate or can I weld and cut larger material just by taking more time on an item. Naturally if I was welding something I could always flip it over and do the other side and that would increase the weld thickness by twice. I hope that I am not asking too much and Thanks for the good help!

By aevald

Date 12-06-2005 00:39

an acetylene cylinder has a draw off rate which governs how much gas can be delivered by the cylinder before it starts introducing acetone into the regulator and hoses (yes this is bad and a noticeable characteristic of this occurring is when you see spitting of small flames out of the end of the tip instead of just having a nice blue colored neutral flame). Acetone is a part of the make-up of the cylinder to keep the acetylene gas from dissassociating and becoming unstable, the instability will occur above 15psi (you will notice on the acetylene regulator that it has a red zone that starts above 15psi, this means not to exceed this pressure on the delivery side of the regulator), this liquid component is also why you need to use acetylene cylinders in an upright position. When an acetylene cylinder is filled, the acetylene gas combines with the acetone and stabilizes the gas and allows it to be pressurized to the 250psi or so that is present in the cylinder. There is a formula that determines if a certain size cutting, heating, or welding tip can be supported by a given size of acetylene cylinder. I believe it goes something like this: if a cylinder had 35 cubic feet of product in it ( this capacity is stamped or listed on the acetylene bottle in some way) you would be able to draw off 1/7th of the contents of the cylinder per hour, or 5 cubic feet per hour. There are charts that will give you the usage rates for a given size of cutting, heating, or welding tip, as long as the particular tip that you are using doesn't exceed this draw off rate you will be able to safely operate that item. If you have questions about this explanation don't hesitate to go to your gas supplier and have them explain to you what all of this means. aevald

By gangel99 (*)

Date 12-06-2005 03:54

You asked, "Also when it says that the materials supplied can only weld to 1/16" and cut to 1" are these numbers total accurate or can I weld and cut larger material just by taking more time on an item. Naturally if I was welding something I could always flip it over and do the other side and that would increase the weld thickness by twice."

.. and you are correct. If you have access and can weld both sides then you can weld to 1/16" on each side.

By weldo

Date 12-06-2005 05:50

Just to add to what the others advised, the size cutting/welding tip you use definitely limits you to what size metal you can cut or weld, there is a quick reference guide that you can get from your supplier for little or nothing, this will tell you and help you understand, not only your tip size for the thickness of metal you're cutting/welding, but also the proper operating parameters of your gases.
I am familiar with the port-a-torch that you're talking about, I have used one just like it several times, and have not yet to this date, overworked one of them, however the little bottles don't last very long if you have to do alot of cutting or welding.
Good luck. Steve

By weldo

Date 12-06-2005 06:30

Sorry, forgot to mention. You asked if you could cut and weld thicker material if you went slower.
Cutting: Yes, but only to a certain thickness, at that point you're no longer cutting, but hacking and melting. I know with me, no matter if I'm doing the work for myself or someone else, neatness always counts, when you cut metal thicker than what the tip size is recommended for, the top edge of your cut, which should be squared off, then becomes a rough rounded edge, because of the amount of heat needed to cut it.
Welding/Brazing:Yes, but there again, only to a point, If you're doing it on the job, you are probably getting payed by the hour, and to most supervisors, they want it done right, but as quick as possible.
I hope I didn't offend you with all the detail, but I'm not sure of your level of experience, and wanted to be as helpful as possible.
Again, best of luck.
Steve