Making Nicer Torch Cuts ???

[aarolar]

Still not simple to cut plate that thick even in a table.

 

[Shield Arc]

Still not simple to cut plate that thick even in a table.

I've been in Fab shops where they cut material that thick. Seems as all the shops used propane.

 

[aarolar]

We run propane it's a lot cheaper.

 

[Arc weld]

Natural gas is popular too on cutting machines. If you have the right tip and the right preheat, the plate could be 12" thick and you could do a cut as nice as Shield Arcs. Thick plate cuts nicer than thin plate and if you're using a cutting machine, there's no excuse for not having a perfect cut. The most common reason for flaws on thick plate is not enough preheat. For bevelling thick plate, they often use an extra preheat torch or 2. A shop up here goes through 200 tips a month fabricating vessel components.

 

[Shield Arc]

In the mid 1970s I helped build a General Electric testing facility, in San Jose California. The plant was a scaled down nuclear power plant, but it would never go on line. There was a pipe welder, who could hold the torch in his right hand, and roll a piece of pipe across the welding table with his left hand. And cut a perfect bevel on the pipe:shocked:. It was amazing to watch him do that!

 

[Gordon Gould]

I worked on my torch cutting a little more. I cleaned the tip first. I adjusted the Ox pressure to give me the jet engine sound with the cut lever down. Had to lower the pressure to do that. It cleaned up the slag and got me square corners top and bottom. Still have to work on speed and angle control but I think I have gained some. This is yesterday's with the top and bottom ground smooth and today's w/o a grinder. Not perfect and there is one place I had to restart. I will try some guides next.

Thanks for the suggestions !! Any more are welcome.

gg

 

[aarolar]

Did you use a straight edge?

 

[Gordon Gould]

Did you use a straight edge?

No, that is what I need to do next. I wanted to try to set it up for the jet engine or ripping noise and by the time I got a feel for that play time was over. Beside lowering the Ox pressure I found making my preheat flame a little softer also helped.

gg

 

[TheMadOne]

It takes practice. Getting the angle and speed right helps a lot. I wouldn't think you'd have to preheat 1/2 inch much. Make sure you have a tip chart that shows the kerf, so you can figure that into your cuts!

For cutting moderately thick material, Oxy tables are nice, but waterjet is king(Up to about 7-8 inches)

 

[aarolar]

Sorry but oxy wins on the thicker carbon plate but of course on stainless and alum there is no comparison.