Ask your WELDING questions here.

[KTM640Dakar]

Do you have a question about welding? How to weld a material or which welding process to use? MIG, TIG, stick, oxyfuel?

If you read through this thread and can't find an answer to your question then ask it in the last page or PM me.

If you are looking for free "how to" welding information search here:

Welding School:

http://www.lincolnelectric.com/en-us...ng-school.aspx

Safety:

http://www.lincolnusmarketing.com/pr...asp?cat=CAT003

Do it yourself read and learn:

http://www.lincolnelectric.com/en-us...materials.aspx

There is good information on safety and getting started in welding if you are new at it.

http://www.lincolnelectric.com/en-us...s/sitemap.aspx

[Poolside]

Could I toss in a technical question about plasma cutting or Plasma Arc Welding?

- Jim

[KTM640Dakar]

Sure. Plasma cutting is good too.

[Poolside]

Say a drag tipped torch cutting .250 carbon steel sheet, with compressed air. The arc is running and the tip is dragging.

What is the approximate power supply output voltage measured across the leads at the supply side? Or, the arc voltage measured between the electrode and the workpiece.

Either one.

- Jim

[Gordy]

OK, this should be easy.

I need to weld some aluminum. I have one of the Lincoln 220V wire feed machines. I am using Argon. Can I just buy some aluminum wire and use the Argon? This is not a critical weld on a frame or anything.

I know............I need a TIG.

[scooteraug02]

Where is the best place to learn to weld?

I was watching a show on CMT, they were fixing up a guy's dump truck and used a plasma cutter tool to cut 2" holes for round lights. The tool was fast and worked like a compass. What is that tool and what other cutting tools are available.

You weld something critical and it needs to hold up. How do you know the weld is strong or correct without beating up your project testing the weld?

Is it true a beer can can be welded if the welder is skilled?

Does grinding a weld weaken it?

[KTM640Dakar]

Originally Posted by Poolside

Say a drag tipped torch cutting .250 carbon steel sheet, with compressed air. The arc is running and the tip is dragging.

What is the approximate power supply output voltage measured across the leads at the supply side? Or, the arc voltage measured between the electrode and the workpiece.

Either one.

- Jim

To cut 1/4 inch plate you will need about 30 Amps. With plasma cutting the voltage is determined by the distance of the tip to the plate you are cutting. You don't really set the machine voltage on a hand held plasma cutter, you set amperage. The key to getting a good plasma cut is setting the right amperage to thickness and keeping the torch slightly above the surface you are cutting without touching the plate. You also need a steady hand, and don't move too fast. If you go too fast the spatter will shoot back at you. You also need clean dry compressed air with the right pressure setting. Most plasma cutters have recommended flow rates for their machine. Usually 65 psi. for a 50 Amp machine as an example. Also make very sure you have a new electrode and nozzle since these parts wear out and will effect cut quality.

Are you using an automated table plasma cutter or hand held plasma cutter? If you are using an automated plasma cutter then you would set voltage to control torch stickout.

[KTM640Dakar]

Originally Posted by Gordy

OK, this should be easy.

I need to weld some aluminum. I have one of the Lincoln 220V wire feed machines. I am using Argon. Can I just buy some aluminum wire and use the Argon? This is not a critical weld on a frame or anything.

I know............I need a TIG.

Yes use argon 100% and get some 3/64 Superglaze 4043 wire. You will also need a teflon liner for your torch and 3/64 or (.047inch) U-grooved drive rolls for your welder. When you get ready to weld set your drive roll pressure in the wire feeder so that it is enough pressure to push the wire but not bird nest the drive rolls if you fuse a tip. Usually you will set the drive roll pressure for aluminum a lot less than for steel wire.

The hardest part about MIG welding aluminum is getting the wire to feed through your welding gun, so keep the welding cable of your gun as straight as possible so the aluminum wire will not have to go through too many curves in the gun cable/liner. That is why you use a Teflon gun liner to reduce friction. There is also a sticker on the inside door of most Lincoln welders that has recommended settings for different thicknesses of metal, as well as different weld wires (like 3/64 dia, Aluminum wire).

If you are using the smaller SP175 220V machine then you might have to use .035 diameter wire.

The best way to MIG weld aluminum is with a spool gun or push/pull gun.

[KTM640Dakar]

Originally Posted by scooteraug02

Where is the best place to learn to weld?

I was watching a show on CMT, they were fixing up a guy's dump truck and used a plasma cutter tool to cut 2" holes for round lights. The tool was fast and worked like a compass. What is that tool and what other cutting tools are available.

You weld something critical and it needs to hold up. How do you know the weld is strong or correct without beating up your project testing the weld?

Is it true a beer can can be welded if the welder is skilled?

Does grinding a weld weaken it?

There are welding classes at most community colleges.

Here is a motorsports training program: http://www.lincolnelectric.com/en-us...ls-course.aspx

http://www.lincolnelectric.com/en-us...on-center.aspx

[Gordy]

Thanks man, I'll try it out.

[G-Force Junkie]

Originally Posted by scooteraug02

Is it true a beer can can be welded if the welder is skilled?

Yes, bottom to bottom, but they have to be empty I probaly got some around the shop I've done, I'll see if I can find them.

Mike
Welder/Fabriator

[tpunzy]

I have tried it with no good coming of it

What the heck is the trick to torch welding (oxy/fuel) aluminum?????? I have seen it done with good results(by an oldtimer), but I (for what ever reason) just don't get it????????????

[Poolside]

Originally Posted by KTM640Dakar

To cut 1/4 inch plate you will need about 30 Amps. With plasma cutting the voltage is determined by the distance of the tip to the plate you are cutting. You don't really set the machine voltage on a hand held plasma cutter, you set amperage.

That's pretty good. You are the first person, Welding Engineer or otherwise, that went right to arc length.

Yea I get that. That the physics of the plasma in any particular gas, in this case air, set the arc voltage over the arc length.

I was just thinking that you might have played around and measured that voltage with a meter, or looked at it on a scope.

I realize I am asking more of a mechanical question. More like "How far back is the electrode from the face of the 'swirl cup' nozzle?" Or terms to that effect.

So, say select one of your more popular Lincoln hand held plasma torches. What is that dimension?

- Jim

[LoFlow]

OK, Here is my question.
On my tig torch I use the old fashioned cups. The brownish red ones. I see on these chopper shows their using clear cups that don't appear to have any neck down to them. I have heard they use less argon for shielding.
Do you have any info or opinions on those? Thanks

[scooteraug02]

Here's the tool I was talking about