MIG Welding questions

[Ken R]

About 5 years ago, I bought a Lincoln 155 wire welder.  Went back a few weeks later and bought the MIG welder accessory kit. 

Here I am five years later . . . . have never used the accessory kit.  But after drilling and welding O2 sensor bungs on my headers, I'm thinking that MIG welding might have made a cleaner job without having to clean, grind, and file before welding a second layer to make sure that it was leak free.  (I'm not a professional welder but have done a whole lot of stick welding in my lifetime).

Any tips on MIG welding that I should know before visiting the welding supply for a cylinder of inert gas?

Ken

[Showdog75]

Get yourself a bottle of C-25 or some call it 75/25 . Don't do the gasless flux-core it's junk . Clean , clean , clean .

[fxstdavew]

Best advice I can give is to practice on the same gage metals to get the machine set up than practice, practice, practice. The finished result will be much better

[Memnar]

I agree, get a bottle of C25 - 75% Argon, 25% CO2.  It will penetrate better than straight Argon. A 125cu ft size will match your machine but will cost the same to fill almost as the 250 cu ft bottle. So decide if you want a huge bottle on the back of the cart - do you want it to do a wheelie, I would guess not.

Call around as the prices vary a lot for buying the bottle and fill, probably as much as $20-$30.

AirGas has their own trade name for it and will tell you it works better than the standard C25 blend, less spatter, bla bla bla, etc.. But its just 16% Argon. Its a good money maker for them but you don't need it.

I don't understand what you mean that you don't need to clean and grind as much with MIG, you do. It just welds faster so you don't get as big heat effective zone. Just think to yourself, if its clean enough to paint its ready to weld.

And yea use just straight wire, .030 I would guess. Not the shieldless crap. I think if you go bigger wire size your machine wont handle it as I bet it has a 20% duty cycle (it should say on front). You can go bigger wire - depends on what your gonna do.


There is really good flux core wire, that makes almost a perfect weld in flat positions, but I don't know if you can get it in a small size for your machine. Oh yea its really expensive big$$$ but would be worth it for welds that will be visible to the public.

Oh one more thing, the flowmeter should be set to 15, more and it actually sucks air into the weld. And you have to weld without a breeze as it blows the shielding gas away..so if a heater kicks on and blows on you it needs to be shut down or moved.

Good luck!

Erik

[hdpegscraper]

I also prefer a flowmeter to a standard regulator. Also, the polarity is different for gas, or gasless wire. My welder has the adjustment inside by the wire spool.

[Ken R]

I don't understand what you mean that you don't need to clean and grind as much with MIG, you do. It just welds faster so you don't get as big heat effective zone. Just think to yourself, if its clean enough to paint its ready to weld.

And yea use just straight wire, .030 I would guess. Not the shieldless crap. I think if you go bigger wire size your machine wont handle it as I bet it has a 20% duty cycle (it should say on front). You can go bigger wire - depends on what your gonna do.


Good luck!

Erik

The only wire welding I've done was with the flux-core wire that came with the Lincoln.  When I mentioned cleaning, I meant cleaning AFTER the welding.  I was thinking that MIG welding produced a cleaner weld with no flux to chip off; and I can see the puddles as they're being formed.  With stick welding, I would be surprised to chip the weld and find voids that were filled with welding flux slag.   LIke I say, I've never used a MIG welder before. I'm hoping I can make prettier welds more consistently with a single pass.

(I used to fabricate 30' long enclosed trailers for competition sailplanes using thin wall square steel tubing for the truss frames.  That's where my experience was achieved.  That was decades ago and so far as I know, the trailers are still in use)

[Memnar]

I don't understand what you mean that you don't need to clean and grind as much with MIG, you do. It just welds faster so you don't get as big heat effective zone. Just think to yourself, if its clean enough to paint its ready to weld.

And yea use just straight wire, .030 I would guess. Not the shieldless crap. I think if you go bigger wire size your machine wont handle it as I bet it has a 20% duty cycle (it should say on front). You can go bigger wire - depends on what your gonna do.


Good luck!

Erik

The only wire welding I've done was with the flux-core wire that came with the Lincoln.  When I mentioned cleaning, I meant cleaning AFTER the welding.  I was thinking that MIG welding produced a cleaner weld with no flux to chip off; and I can see the puddles as they're being formed.  With stick welding, I would be surprised to chip the weld and find voids that were filled with welding flux slag.   LIke I say, I've never used a MIG welder before. I'm hoping I can make prettier welds more consistently with a single pass.

(I used to fabricate 30' long enclosed trailers for competition sailplanes using thin wall square steel tubing for the truss frames.  That's where my experience was achieved.  That was decades ago and so far as I know, the trailers are still in use)


Oh - ok. I understand you now. Yea MIG is usually cleaner. Another trick is to use the spray anti-spatter and spray around where the weld is, but not the area to be welded. Just tape where the weld bead will be before spraying. Its kinda like Pam cooking spray.

Like I said if you want a super weld some of the flux cored wires that are gas shielded will not spatter and the slag formed will knock off a 2 foot section with one wack...its awesome and the weld can look perfect.

oh and on stick welding, sometimes if your getting those little holes in the bead it might mean you have too much heat, try turning down the welder just a little bit. Other voids/things we would have to see the bead.
But you should kick butt if you have been sticking it for a while..
Good luck...

[Ken R]

Thanks, Memnar and everyone else.

Yesterday, I went to Harbor Freight and bought a cart . . .. finally!  5-years of pulling the welder out of the shelf and untangling cables is enough!

Spent a couple of hours today converting the wire welder to a MIG welder.  Instructions were confusing, but got 'er done just fine.  I just happen to have a cylinder of CO2.  Instructions said it can be used (or C25 Argon mixture).  I'll use up my CO2, first. 



Then, I practiced, first on 1/8" steel.  No problem, welds look good and penetrate well.  I sure like the sound of MIG welding.  More of a "bizzzzzzzz" sound instead of "sputter/sizzle/crackle". 

Then, went to my nemesis, thin sheet steel.  I have some 24 gauge stainless.  Found it to be incredibly easy to weld.  First practiced with a few beads on the surface.  Then, lap-joined two scraps together.  No problemo.  Then, tack-welded a nut to the surface of the thin SS to get the feel for 1/4" thickness to very thin metal welding.    I'm very happy with the results.   The picture looks ugly, but I often weld nuts to flat plate for anchors and such.  Usually only tack-weld on two opposite sides since the only purpose is to hold the nut in place for screwing a bolt from the other side with T-handle bolts for quick connection of tools and jigs. 

The heat and wire-feed table inside the door helps a lot.  I do have to figure out how to tension the spool.  Right now, it wants to tighten up as wire unspools.  The spool rubs against the plastic wing nut and turns it into the tightening direction.  There must be a part missing, a spacer, maybe.



and

[jambo]

You dont have to use shield gas when you run this it will be somewhat cleaner with 75/25 but flux core does pretty good. It just takes practice to make good welds. One way to set your heat is it should sound like a 'mud dobber' a wasp that makes its nest out of mud, a buzzing sound. good luck 

[northbrun]

RE a part missing.. I beleave there should be a nylon washer that is keyed to the shaft so the spinning spool won't tighten the nut and can slip on the washer..

[mark61]

    Properly set up Mig welding should sound like bacon frying.......no matter whether you are using 25 amps or 600 amps.
    Welding used exhaust is not the easiest since the gases and flames in the pipes eat away at the metal inside and make it thinner...Practice makes perfect.    Your welds looking like you are improving there!

mark61

[mayor]

I just happen to have a cylinder of CO2.  Instructions said it can be used (or C25 Argon mixture).  I'll use up my CO2, first. 

I always used the argon blend when I welded at work, but I'm curious about what you thought of using CO2?  I just got a used Mig that was set up for a tank but it didn't come with a tank, but I have a fairly full CO2 tank in my keg system. 

[Ken R]

I just happen to have a cylinder of CO2.  Instructions said it can be used (or C25 Argon mixture).  I'll use up my CO2, first. 

I always used the argon blend when I welded at work, but I'm curious about what you thought of using CO2?  I just got a used Mig that was set up for a tank but it didn't come with a tank, but I have a fairly full CO2 tank in my keg system. 

To my untrained (but becoming self-trained) eye and ear, the CO2 worked just fine.  It appears to have shielded the arc from oxygen so that the solid wire fused pieces together without any issues.  I tried to break my sheet stainless steel welds but they're pretty much permanent.  I was happy to have a cylinder of CO2 handy from when I shot adult airguns.  The Lincoln conversion kit just happened to include a CO2 cylinder adapter.  So, I won't buy any C-25 until the CO2 is used up. 

Ken

[hunter]

Ken R,

You inspired me.  I pulled out my unused 135 handler and finished fabricating my trailer tailgate.  Had a great time.  I'm digging around in my garage looking for more metal that needs mended.

[Ken R]

Ken R,

You inspired me.  I pulled out my unused 135 handler and finished fabricating my trailer tailgate.  Had a great time.  I'm digging around in my garage looking for more metal that needs mended.

Yeah, welding is great fun.  And it's so different from woodworking.  For one thing, there's no waiting for glue to dry. . . . . instant gratification!
And there's no sawdust to get all over everything and require huge cleanup.
And the other thing is that if you cut something too short, no problemo . . . . just weld it back together and cut it again.  Nobody will know. 

Ken

[harpo1313]

just blow your airgun into the intake vent once in a while,welding is an art,always wanted a plazma cutter but still using a 4 inch cutoff wheel and my sawzall

[Memnar]

I also prefer a flowmeter to a standard regulator. Also, the polarity is different for gas, or gasless wire. My welder has the adjustment inside by the wire spool.

Keep in mind that a regulator and a flowmeter are different in simple terms.

For MIG welding you need a flowmeter  -usually (but not always) has a vertical glass tube with a little ball that "floats" on the gas flow. Regulates gas flow.

A regulator is what is usually used on your OXY/ACET torch set up to regulate the gas pressures.

You would not believe how many people have come into the welding store saying their regulator or flowmeter does not work just to find out they had the opposite.

[Ultrashovel]

The typical MIG welder is supplied with a special type of regulator that supposedly reads in standard cubic feet per hour. (SCFH)  Typically, they are hard to read and fairly inaccurate. I use a Smiths ball-type flowmeter that has scales for argon and CO2.

For mild steel using MIG, Ive tried C25 (75% argon/25% CO2) but I prefer straight CO2. It gives better penetration and costs less than half of C25. It also has a smaller bottle for the same amount of gas. CO2 is sold by the pound and one pound equals a little more than 8 cu ft of gas. So a 20 pound cylinder is the same as a 160 cu ft gas cylinder. It does give a bit more spatter but if you keep the tip clean and soaked in welding gel, you really won't notice it.

You can also do stainless steel and aluminum with your MIG using straight argon. For aluminum you will need either a spool gun or a teflon gun liner. 

[Ken R]

The typical MIG welder is supplied with a special type of regulator that supposedly reads in standard cubic feet per hour. (SCFH)  Typically, they are hard to read and fairly inaccurate. I use a Smiths ball-type flowmeter that has scales for argon and CO2.

For mild steel using MIG, Ive tried C25 (75% argon/25% CO2) but I prefer straight CO2. It gives better penetration and costs less than half of C25. It also has a smaller bottle for the same amount of gas. CO2 is sold by the pound and one pound equals a little more than 8 cu ft of gas. So a 20 pound cylinder is the same as a 160 cu ft gas cylinder. It does give a bit more spatter but if you keep the tip clean and soaked in welding gel, you really won't notice it.

You can also do stainless steel and aluminum with your MIG using straight argon. For aluminum you will need either a spool gun or a teflon gun liner. 

I'm using what came with the Lincoln MIG conversion kit.  Looks all the world to be a regulator; although no adjustment knob (unadjustable).

[Ultrashovel]

The typical MIG welder is supplied with a special type of regulator that supposedly reads in standard cubic feet per hour. (SCFH)  Typically, they are hard to read and fairly inaccurate. I use a Smiths ball-type flowmeter that has scales for argon and CO2.

For mild steel using MIG, Ive tried C25 (75% argon/25% CO2) but I prefer straight CO2. It gives better penetration and costs less than half of C25. It also has a smaller bottle for the same amount of gas. CO2 is sold by the pound and one pound equals a little more than 8 cu ft of gas. So a 20 pound cylinder is the same as a 160 cu ft gas cylinder. It does give a bit more spatter but if you keep the tip clean and soaked in welding gel, you really won't notice it.

You can also do stainless steel and aluminum with your MIG using straight argon. For aluminum you will need either a spool gun or a teflon gun liner. 

I'm using what came with the Lincoln MIG conversion kit.  Looks all the world to be a regulator; although no adjustment knob (unadjustable).

No adjustment? How do you set the rate? I had one that I traded off the one that came with my Lincoln 175 Plus. It had an adjusting knob. I run around 20 cu. ft. per hour. I replced it with a Smiths ball-type flowmeter. If I were you, I'd get the ball type. They are quite accurate and they give you a view of the actual gas flow. They are on eBay all of the time.

If you get one, try to geta  Victor, Smiths or an Ox-Weld.