Welding

[rhett]

Hello all. Fairly new to TBN (still learning how to get around the site) A question if you don't mind. I've been playing around with an old Lincoln stick welder. New at welding but am getting better with practice, I think. The old stick welder seems to do a good job but I hear so much about MIG welding. So my question is what are the advantages of MIG welders/welding. I ask because they appear to cost more then a stick welder. Especially for thicker metals (3/8ths 1/2 inch) and I'm curious as to what justifies the added cost?
Thanks

Metal Inert Gas (MIG) welding machines have production advantages and process versatility.
a) easy to operate and almost continuous filler metal feed.
b)with correct gas and filler wire, steel and many alloys can be welded (stainless steel, aluminum ...)

Trying to clear up a misconception of needing larger machine outputs. It is only needed if production requires thicker material to be welded in one pass. Multiple passes will weld materials as thick as you desire, just more practice for you working the puddle. Then a Cap pass and things will be beautiful.

Also their ability of using the Flux Core process (Innershield), giving a great advantage of not requiring shielding gases for mild steel projects. Innershield is always my choice of process used for mild steel projects, I guess the shipyard made me confident with it.

As for Stick, a 7018 weld cannot be beat for a demanding project.

Rhett

 

[irvingj]

Thanks Rhett-- and all else who share welding knowledge. That's one of those skills I was never confident about, though I've tried it a few times over the years.... Sure wish I'd paid more attention to the old bodyman (artisan?) I had the good fortune to work with in the mid-60s....

I finally signed up for a welding course at the local Vo-Tech center, soaking up everything I can, also reading all I can find on the TBN-- what a great site!

 

[wowbw7]

so, RHETT, if i can jump in here. you seem to know welding quite well. i'm a novice at best, have used mostly 6013 and mild steel. i'm formulating plans for a log splitter attachment for my backhoe utilizing the bucket cylinder as the ram. i plan on using 1/2" mild steel for the bed, and a wedge purchased from Northern welded to a 1/2" sled attached to the cylinder as the ram. Northern recommends a 'low carbon' welding rod. i have some 7018, 1/8 rod and an old Forney buzz box, 180 amp i think. will this do the job, do you think? and if so, can you recommend a heat setting? thanx

 

[rhett]

Northern recommends a 'low carbon' welding rod. i have some 7018, 1/8 rod and an old Forney buzz box, 180 amp i think. will this do the job, do you think? and if so, can you recommend a heat setting? thanx

Yes, 1/8" 7018 suggested amp range is 90-160 amps.

I will recommend properly beveling (grinding) work pieces so penetration is not an issue. Do multiple passes, with each pass about twice the width of the 7018 rod. You know the 3 point weave pattern until the 1/2" materials bevel is filled. This method I will suggest 95-115 amps.

You could do the 6013 root pass, I doubt you will x-ray the weld, and doubt the welds will fail.

The best welding lesson anyone can ever have is watching over the shoulder of an experienced welder, with the understanding that the puddle is the point that eye hand coordination is to be of concentration. Welding is an art. Science too, but the labs already did that part.

Rhett

 

[groundcover]

WOWB make sure to get the 7018AC if you are useing a AC buzz box, will run out and hold the arc much better.

 

[Sackett2]

my 2 cents
Get a auto dimming helmet. the best darn investment I have made in regards to welding- mig or arc (no tig yet ) My welding quality improved a ton by changing helmets

 

[Workstead]

Metal Inert Gas (MIG) welding machines have production advantages and process versatility.
a) easy to operate and almost continuous filler metal feed.
b)with correct gas and filler wire, steel and many alloys can be welded (stainless steel, aluminum ...)

Rhett

Hi Rhett,

Thanks for your good technical advice.

Could you tell me more about welding aluminum with a mig welder? I have a Miller with a gas bottle and regulator. I recently bought 2 pounds of aluminum .030 wire. What else do I need to weld aluminum? Any special techniques to do a good job?

Thanks,

Clem

 

[rhett]

Could you tell me more about welding aluminum with a mig welder? I have a Miller with a gas bottle and regulator. I recently bought 2 pounds of aluminum .030 wire. What else do I need to weld aluminum? Any special techniques to do a good job?

Thanks,
Clem

Hi Clem,

Your Miller operators manual should have the settings needed for Aluminum. I'll list a few things that should be of help.

DC+ is used for both Stainless Steel and Aluminum.
For aluminum use a larger size tip than wire to improve wire feed (ex: .030 wire, use .035 tip). If allot of aluminum is to be welded for future projects consider getting a "Spool Gun".
For aluminum use 100% Argon.
For Stainless use 98% Argon/2% Oxygen.
Run test welds before starting on the project.
Clean surface is very important, use Stainless Steel Wire brush, brushing in one direction only.
Aluminum wire feed speeds are increased 2X too 2.5X that of steel wire, so your welding movement must increase.

"From a Manual: It is important when changing between welding with steel wire and aluminum to exchange feeding components due to the lubricant applied to steel wire. Failure to do so may result in contaminated welds when welding aluminum."

Good Luck
Rhett

 

[AlanB]

While not asked, I will chime in a bit.

While it is certainly possible to weld aluminum with your basic Mig (it is done all the time) it is also a little trickier than it sounds.

The example I use is that in normal steel Mig welding you are pushing a raw spaghetti noodle through a tube from the welder to the tip of the gun and bumping the surface you are trying to weld.

When doing aluminum, you have cooked the noodle, you are pushing twice as fast, and you are slamming the end into the metal.

If you do not know the definition of Birdsnesting when speaking of Migs, you will after trying aluminum in a standard gun.

If you do decide to do it, A new liner is important.

VERY VERY straight gun hose helps a lot.

And a lot of patience to undue the birds nests as you learn.

Good luck if you go that way, I would only do it if it was the only way I had available too me.

 

[MJPetersen]

About a year ago I got a mig machine and it was advertised as being able to do aluminum. I had never had a MIG before, only stick so all in all mig is a new experience for me. My only experience with aluminum was in high school many years ago with a machine to do TIG. All I remember was that about the time that you got a nice puddle and it turned all shiny, just the instant before the whole thing fell out onto the floor!!

I really want to get a spool of aluminum and give it a try, just for the sake of saying that I have tried it. I laughed at your bird's nest description as I can see how that would happen. I also want to give stainless a try. I have a neighbor who dos alot of stainless work and he is a craftsman with it. He has a tig now, but for years he used a MIG. he does not do aluminum and has never tried. He has his won welding business.

Mike