Setting up my MM251 for Aluminum

[MtotheIKEo]

What do I need to do to setup my 251 for welding aluminum? Right now I am running .030 s-6 wire and 75/25 gas. I need to switch to pure Argon right? And what exactly does the spoolgun do that the regular gun doesnt?

[aametalmaster]

Yes you need Argon for the gas along with the alum wire. The spoolgun eliminates the birdnesting and feeds the wire better than your mig gun. Plus it gives you some extra reach because the cables are longer. I did a comparison a while back, spoolgun vs regular mig gun. i will look it up...Bob

http://www.millermotorsports.com/mboard/showthread.php?t=3929

[MtotheIKEo]

Is the spoolgun a necessity, or a nice thing to have?

[aametalmaster]

It is a nice toy if you don't do a lot of alum welding. I used to weld alum in a factory daily with a Miller Mig and a regular mig gun and teflon liner. It welded just fine, but i haven't had such good luck at home. Yes the Spoolgun and bottle will set you back 600 bucks or so but in my warped mind it is worth every penny. i still have my dads 1962 spoolgun and alum welder back when the migs were a dream...Bob

[MtotheIKEo]

Cool, thanks for the advice. I work at a building company as a welder. I MIG weld anything from 14ga sheet metal to 1/4" tube all day. I have TIG welded Al a little, but never MIG'd Al. I do a little welding for my gf's step-dad's company every now and then when he has work for me, and today he asked if I could do aluminum. I have never had a need to do it at home, I have always done mild steel, so I never set up my machine for it. Now that he is asking it might be a good excuse to go buy a cylinder and a spool of wire, but I dont have the cash to drop on a spool gun right now.

[aametalmaster]

Check with your dealer about a teflon liner also, it is smoother inside than running thru the steel conduit...Bob

[MtotheIKEo]

Check with your dealer about a teflon liner also, it is smoother inside than running thru the steel conduit...Bob

It would work though? I have a short lead, its the stock gun/lead that came with the machine.

[Stick rod]

It would work though? I have a short lead, its the stock gun/lead that came with the machine.

We`ve tried that before and didn`t have much luck.Just don`t get your hopes up.I`ll be pulling for things to go O.K. with switching liners etc....

[calweld]

I have no personal experience with running aluminum wire through a regular mig gun, as I use a spoolgun, but I would think using a heavier wire (like 1/16 or better) would give better results than the 035 or 045. Just a thought.

[fun4now]

also you might look into useing the harder aluminum wire, i just got up so my pills are working but not my brain so you will need someone else to give you the exact alloy but its the 5??? series insted of the 4??? sory i cant be more spacific but your dealer will know what in talking about, its a harder wire and will help reduce its want to birds nest. some have also advised going up 1 size bigger in the tip than the wire to alow for the wire to expand with the heat.so you might keep an extra tip handy incase it needs it. also you cant prep aluminum with steel, so you will need to get a ss wire brush ans only use it for aluminum. changeing out the liner will also be helpfull as not only will the teflon help but it will keep the aluminum wire from picking up any metal shavings or dust out of the old lining.i'm shoure as soon as i end this post ill remember the alloys

[fun4now]

5356

5356 is a harder aloy and will help it push threw

and slowly the brain awakens

also keep in mind the 5356 will produce a darker bead then the 4043 will, so if a good colar match is needed you should stick to the 4043 as it will colar match better. but be a bit more apt to birds nest. try to keep the gun liner as strait as possible, the more bends in the line the more likly it will birds nest.

also you might do a serch on here for "aluminum" to get a lil more imput on the prep required for aluminum, its a fickel thing and clean is a big deal. never use the same stuff you prep steel with to prep your aluminum. ss wire brush(steel wire brush is BAD) and new scotch bright pads and whatever else you intend to prep with grinding disks and flap disks if needed. any lil bit of steel on thease and you will get realy bad results so it would be best to just get a new setup just for aluminum and keep it on a seperate shelf or box so you dont get them mixed up.

if this is a job for dady you might try to get him to spring for the bottle. setting up for your first aluminum can get a bit $$$ as you need to get a second set of all your prep stuff as well as a new bottle, if its just a 1 time thing you could always farm it out. ofcorse once you get set up the first time after that you will be set for future jobs without the high start up $$$. always nice to add to the toy box

[jeffscarstrucks]

You probably already know this but it can be easily overlooked or forgotten when you weld steel all of the time: use a "push" rather than a pull as it relates to gun movement when using a MIG on aluminum. I only point this out because I still have to remind myself once in a while! Good Luck, JEFF

[MtotheIKEo]

You probably already know this but it can be easily overlooked or forgotten when you weld steel all of the time: use a "push" rather than a pull as it relates to gun movement when using a MIG on aluminum. I only point this out because I still have to remind myself once in a while! Good Luck, JEFF

I have never MIG'd aluminum, so thanks for the advice.

[Stick rod]

I have no personal experience with running aluminum wire through a regular mig gun, as I use a spoolgun, but I would think using a heavier wire (like 1/16 or better) would give better results than the 035 or 045. Just a thought.

Very true.Larger diameter will feed better.Still partial to a spool gun or the other alternative is a push-pull set-up.

[Merc69]

Years ago I was involved in fabrication and welding aluminum awning frames. A spoolgun was invaluable in that type of fabrication. If your aluminum work is small or at least where you can move your welder close, then the teflon liner would work fine.

I may wind up doing this type of work sometime in the near future, and will have to buy a welder capable of structuraly sound and cosmeticly pleasing. As this is a production setting, the fine folks at Miller suggested a 350P with the pulsing and a push-pull setup.

Good luck and I personally recommend the spoolgun...just my opinion