MiG welder: how thick can it weld?

   / MiG welder: how thick can it weld? #1  

sevilla

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L3830
Hi, I never welded but I'm thinking to give it a try. The point is that I know nothing more that what I could find in the pages of the various manufacturer of welding machines. I will use the welder on tractor related equipment and therefore on 1/2 inch of iron or more.
I was initially considering a stick welder now I'm thinking of a MIG welder. My question is: a MIG welder rated for 1/8 or 3/16 thick iron will weld a thicker iron? Will eventually the weld be good? I'm not so much interested in speed of welding since it will be more of a hobby.
Also, which are the difference between a Miller and an equivalent Hobart (I believe they manufactured by the same company).
thank you very much.
 
   / MiG welder: how thick can it weld? #2  
;)The rule of thumb for MIG welders utilizing single pass is 1 amp per .001 in of thickness or 250 amps for 1/4 inch. Of course you can make as many passes as you want (using the right wire).

Many people will say that they weld 1/2" all day long with 180 amps, but the penetration is not there.

For 1/2" I would recommend a stick welder.

By the way, a MiG is a Russian fighter which probably doesn't make good welds. :D:D:D
 
   / MiG welder: how thick can it weld? #3  
I hate welding threads...they almost always take a turn for the worst-but here is my short answers:

My question is: a MIG welder rated for 1/8 or 3/16 thick iron will weld a thicker iron? Will eventually the weld be good?
No. To weld 1/2" material properly you need a 220 volt machine.

Also, which are the difference between a Miller and an equivalent Hobart (I believe they manufactured by the same company).

The Miller is more "commercial" or "industrial", with a liitle better specs, higher duty cycle, and metal drive components. The Hobarts are great machines for a hobbyist, but have plastic drive components, less duty cycle, and often less adjustability.
 
   / MiG welder: how thick can it weld? #4  
I have a Lincoln 180 220v MIG. I can usually get two pieces of 1/2" to hold together if I chamfer the edges of the pieces being welded and fill in the trench.

I can also make welds on 1/8" that are so lousy they will fall apart just looking at them. Prep and technique have a lot to do with the weld quality.

For me the Lincoln 180 is a perfect size and I have seldom felt limited. I get much better results than with a stick... mainly because I don't spend all day every day with a stinger in my hand. (I think MIG is great for hobbyists) A 120v rosin core wire feed usually gets frustrating very quickly for a newb.
 
   / MiG welder: how thick can it weld? #5  
What I did and feel is a great setup for us tractor guys is get 2 welders. I got a Hobart 187 MIG and use it 99% of the time. I weld 1/4" with great results using .030 wire. I do not care for .024 wire after trying it. I got in on sale at TSC with a cart, helmet, gloves, hammer, ect for $525 with a coupon I had 3 years ago.

I also picked up a used Miller 250 Stick Welder. Its a oldie but a goodie and came with 50' leads and about 10# of rods for $100 cash. I have only used it a few times but has came in very handy.

Chris
 
   / MiG welder: how thick can it weld? #6  
Spend $60 and get a used Lincoln tombstone....
 
   / MiG welder: how thick can it weld? #7  
If you can take a welding course first. I know a lot of people are self taught but it helps to do a little of each type of welding before you buy a machine.
Personally I have a Miller 251 and I love that machine.
 
   / MiG welder: how thick can it weld? #8  
The thickness rating you talk about 1/8 or 3/16, usually refers to single pass.

All you got to do is chamfer and make multiple passes. Even a "average home" stick welder cannot weld 1/2-3/4" in a single pass and get penetration all the way through.

If you are just hobby welding and nothing structural, the mig will be just fine. But I agree, stay away from the 110v and the flux-core stuff. Get a good 220v welder 180-250amps, will do just fine for most home welders.
 
   / MiG welder: how thick can it weld? #9  
A quick answer... MIG uses a small (compared to stick) wire. Unless you get a commercial unit, they aren't designed to weld heavy stuff. In order to properly fuse metal, the metal must be heated to the melting point. Metal is also a good conductor of heat and the thicker the metal, the more current needed to keep it at that point. Hence, MIG will weld cold on thick stuff, and will not penetrate. Get a Tombstone welder, and a couple of classes. ( The decimal equivilent of 1/8" rod is .125, This is your starting current...125 amps)
 
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   / MiG welder: how thick can it weld? #10  
When it comes to MIG welders, there are three "classes" of machines, I will get some discussion on the limits, but in *general* :)....

1) 120 & 220V "compact" welders sold mostly at discount stores.
- Used for welding sheet metal to about 3/16"
- Mostly used with "Flux Core" wire
- Some can be used with shielding gas (true MIG)
- Have nameplate ratings at 80% "duty cycle" or more of 190A or less.
- NOT suited for welding anything over 1/4" or "big projects", sure they can be made to work.
- Steel only on smaller units, AL ability on advanced units.
- $350 to $1000

2) 220V "Mid-range" MIG welders from the LWS (some carried at discount type stores)
- Used mostly for 1/8" thru 1/4" material (single pass) and up to 5/8" with multiple passes (larger units).
- MIG as-built, but can be converted to flux
- Nameplate ratings at 60% duty cycle of at least 180A (200A-250A typical)
- Suitable for light to medium production welding of material 1/2" and thinner.
- Steel only on the entry-level units unless a "spool gun" is used, more advanced units can weld steel and Al easily with a spook gun.
- $850 to $3500

3) 220v+ "3 phase" welders
- Used on metals from 16ga to 1"
- MIG only
- Nameplate ratings at 20% - 30% duty cycle of 250A and greater (to ~400A)
- Suitable for industrial applications and robotic welding.
- Will weld almost anything weldable with the MIG process
- $2500 to $10,000 and more.

I own and use a Miller brand MillerMatic 251 in MIG mode with mixed gas and 0.035" wire. I CANNOT make good quality welds on 1/16" steel, it warps too much because the minimum current is too high. I will make BEAUTIFUL welds on 3/16" to 5/16" steel with nearly 100% penitration and no beveling. Whatever you weld togather will STAY togather.

I looked for a long time at welders and really wanted to stay under $1000 for everything. In the end, I could not justify spending even $650 on some small welder that would not make quality welds with good voltage controls. I spent about $1400 in total for everything I needed on a good used MM 251 and am GLAD I got the larger unit!

There IS a noticable difference in the weld quality and arc quality of the larger "full frame" machines over the compact units.
 
 
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