Mig Welding

[Fishfiles]

I have welded MIG a lot with machines that were already setup , and only had to change the spool of wire and the bottle , but I bought my first Lincoln Mig Welder that burns shielded and unshielded and I am in the process of setting it up for aluminum , the manuel , the web site and the disc that came along with it all leave me guessing which way to set the polarity for either type of welding as it states the machine is shipped in one configuation but appears to be in the other, I am thinking flux core (unshielded) work clamp is attached to the negative (-) and gu to positive (+) , and vice versa for the shielded process for aluminum , Any MIG'ers out there

 

[nailsbeats]

Congrats on the Lincoln! You can't go wrong with any of their products, they are the industry leader in my opinion. Anyway, if you are going to weld with flux core then you will want reverse polarity, ground positive and gun negative. For the shielded aluminum you want standard polarity, ground negative and gun positive. Have fun!

 

[OldMachinist]

Electrode or wire negative for flux core amd positvie for solid.

 

[Fishfiles]

Electrode or wire negative for flux core amd positvie for solid.

Thanks for the replies , got the MIG on steel working with and without the gas , welds much cleaner with the gas and solid wire , rather than core wire --------next step is getting the aluminum set up working was told 100% argon is much better for alum than the 25 argon and 75 co2 tank I got now , which would mean getting another tank , it's allways something

 

[Jeffscarstrucks]

Thanks for the replies , got the MIG on steel working with and without the gas , welds much cleaner with the gas and solid wire , rather than core wire --------next step is getting the aluminum set up working was told 100% argon is much better for alum than the 25 argon and 75 co2 tank I got now , which would mean getting another tank , it's allways something

You are correct in using straight argon for AL welding. You must also clean your work very well before welding and "push" the gun rather than pull it. You will find that your travel speed will be faster than you would use with steel and that wire speed is also considerably faster as well. Al can be tricky to get started with when you are setting up a new machine but it is not really any harder...just different.Good Luck, JEFF P.S. The Miller web site has a forum that you can search much like this one at Millerwelds.com then motorsports then "Ask Andy" forum. It is called a motorsports forum but it has really been a welding forum for the years that I have been there. Lately there have been some off topic dopes show up on there but overall it is a very good source of general info as well as some very job specific info. There are a few big equipment repair guys over there who have shown some step by step repairs on some REALLY big stuff.

 

[Fishfiles]

You are correct in using straight argon for AL welding. You must also clean your work very well before welding and "push" the gun rather than pull it. You will find that your travel speed will be faster than you would use with steel and that wire speed is also considerably faster as well. Al can be tricky to get started with when you are setting up a new machine but it is not really any harder...just different.Good Luck, JEFF P.S. The Miller web site has a forum that you can search much like this one at Millerwelds.com then motorsports then "Ask Andy" forum. It is called a motorsports forum but it has really been a welding forum for the years that I have been there. Lately there have been some off topic dopes show up on there but overall it is a very good source of general info as well as some very job specific info. There are a few big equipment repair guys over there who have shown some step by step repairs on some REALLY big stuff.

Thanks Jeffscarstrucks , that is some very helpful info that I can relate to as I took welding classes but never did get into aluminum, probally cause that was in 1976 and aluminum welding wasn't as much as it is today , always wanted a MIG machine and the price finally got right ----------I fish at lot and have a boat , always need something welding in aluminum or stainless , do you have any tips about setting up for stainless ------------did my first real job today with the machine , a T300 's Power Bobtack cylinder took a hit and broke the 90 degree fitting off the case , was able to grind the old chunk off and MIG a new fitting onto the cylinder and it didn't leak , in the past I would stick rod them and have small bust out bubble holes and have to do it again ------fishfiles

 

[nailsbeats]

Thanks Jeffscarstrucks , that is some very helpful info that I can relate to as I took welding classes but never did get into aluminum, probally cause that was in 1976 and aluminum welding wasn't as much as it is today , always wanted a MIG machine and the price finally got right ----------I fish at lot and have a boat , always need something welding in aluminum or stainless , do you have any tips about setting up for stainless ------------did my first real job today with the machine , a T300 's Power Bobtack cylinder took a hit and broke the 90 degree fitting off the case , was able to grind the old chunk off and MIG a new fitting onto the cylinder and it didn't leak , in the past I would stick rod them and have small bust out bubble holes and have to do it again ------fishfiles

Fishfiles, for stainless use stailess wire and an argon-helium-co2 mix for your shielding gas. This will give you a good, clean stailess weld.

 

[Jeffscarstrucks]

Fishfiles, for stainless use stailess wire and an argon-helium-co2 mix for your shielding gas. This will give you a good, clean stailess weld.

I'd go with what nailsbeats said as I don't have a hand full of stainless experience with MIG.I have always TIGed the little bit of stainless I had to do. You will be able to MIG some components or build some brackets or accesories for your boat but make sure that you are very comfortable with the process before you work on thin material. Al can be Mig welded down to the lower thicknesses but it is tricky and is often done with a pulse mig machine. I normally will TIG under an 1/8th thick if it is not too long. I have not had time to do much lately so I will look forward to hearing about you progress. Good Luck, JEFF