Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Welding

SFT Search:   
Thread Tools Display Modes
Old 01-22-2009, 06:53 PM
Hurricane Hurricane is offline
Junior Member
Join Date: Jul 2007
Location: St Louis, MO
Posts: 36
Default Aluminum mig question

I just started mig welding aluminum today with decent results, but i have a few questions you guys may be able to answer for me. decent looking beads w penetration once i get moving, though i dont seem to have enough amperage to penetrate from the start, have to get some heat in it first.

my setup - 145amp machine, turned all the way up
5356 filler wire .030, 3/16" 5052 plate, 25cf straight argon

1- how fast should my wire speed be? the machine has a 1-10 dial, best results have been at 7, any slower and i get a lot of burn back, sticking the wire in my tip

2- how much stickout should i use?

3- im getting a HUGE amount of white smoke while welding, is this normal or am i doing something wrong? looks like welding galvanized steel, is this going to make me sick?

4- can somebody explain what spray transfer is? dumb it down for me if you can

i also bought a roll of 4043 wire, but have trouble getting it to feed. will try again once my teflon liner and roller get here. thanks

Last edited by cutter; 03-15-2011 at 08:17 PM. Reason: remove hacker link
Reply With Quote
Old 01-22-2009, 07:22 PM
pumpertruck's Avatar
pumpertruck pumpertruck is offline
Spinner of Wood
Join Date: Apr 2008
Location: Pothole Hell, Anoka county, MN
Posts: 3,406

It's been a few years since I have run aluminum so I am a bit rusty. I can't help you on the settings although a 145 amp machine may be a bit on the small side. I ran with 600 amp capacity. We ran with 1/2" stickout. The white smoke is normal. Don't breath too much of it. Spray transfer is when you get the voltage higher. I think I ran .035 at around 26 volts. If you want to cough up the extra money you can run a helium/argon mix for a lot hotter arc. If I remember right, 4043 is a softer wire and doesn't feed very good unless you have a push/pull feed system. Most of my aluminum mig was running .045 or .062 on 1/4 to 4" thick stock. Like I said, it's been a few years.
Shorter of breath and one day closer to death.....
Reply With Quote
Old 01-22-2009, 10:41 PM
mccutter's Avatar
mccutter mccutter is offline
Post Fiend
Join Date: Mar 2006
Location: Central Florida
Posts: 8,668
Default Some like it hot...

I'm sure many of us here will tell you that you are potentially spinning your wheels trying to weld aluminum with a MIG gun, teflon liner and "weak" machine. Aluminum needs a lot of heat (amps). And I (we) speak from experience--been there, didn't do that because it didn't work all that well.

The scenario is that in order for the wire to feed and not birdcage you need a stiffer wire (5356). Right off the bat, 5356 needs about 15% more amps than 4043 to weld properly, hence, your machine is "turned up all the way". You may never get enough heat into the work to get good penetration, especially 3/16". You might do OK on thinner gauge. I don't think the liner will help you that much with 4043--the MIG gun has to remain nearly straight, especially with a thinner wire.

This is not to say that it can't be done--maybe try some pre-heating of your work with a propane torch? I can't help you with your settings.

A good rule of thumb is to not breathe ANYTHING coming off of the weld. Hold your breath or use a respirator. I can't explain the white smoke...maybe normal?

Normal MIG welding is done with the "short" method (vs spray). The filler wire contacts the work piece, shorts out, heats up like a lightbulb, then melts into the puddle. This is continued over and over again while the trigger is squeezed.

With spray arc, the filler wire melts BEFORE it reaches the workpiece and is deposited in smaller drops but at a higher rate. This process requires much more power and is used on the larger, higher-end machines.

Read the attached pdf courtesy of Miller--it is a little more descriptive of the various processes.
Attached Files
File Type: pdf migarcs.pdf (173.2 KB, 765 views)

TA Arcmaster 185 w/tig/stick kit
MillerMatic 252 w/3rd gen 30A
MM140 w/o AS, w/CO2
Hobart (Miller) 625 plasma
Hobart 250ci plasma
Victor O/A (always ready, but bored)
Lincoln Patriot autodark (freebie)
45ACP Black Talons for those stubborn jobs...
Reply With Quote
Old 01-23-2009, 07:29 AM
LW Hiway's Avatar
LW Hiway LW Hiway is offline
Lord of the Minions
Join Date: Jun 2005
Location: Indian Bayou and Lake Charles, La.
Posts: 21,320

A good rule of thumb is to not breathe ANYTHING coming off of the weld. Hold your breath or use a respirator. I can't explain the white smoke...maybe normal?
How long can you hold your breath. lol

The smoke coloration won't always be the same, but that's about the closest description.

Hurricane, if you do a search on here back to about 3 years, you'll read more threads than you have time to sit through on some very specific information dealing with MIG and aluminum.

Your machine is pouring it's heart out for you working that 3/16" Al. Your starting beads will be just as you mentioned, unless you possibly do a little preheating where you start.
God, if you would grant me one request through Prayer, please help me be the Man my Dog thinks I am. Please.

Quoting "The Hunt". "A man will walk into hell with both eyes and arms wide open. His dog will know better."

I never thought I'd live long enough to become a grumpy old bastard. Here I am, killing it!
Reply With Quote
Old 01-23-2009, 12:31 PM
Hurricane Hurricane is offline
Junior Member
Join Date: Jul 2007
Location: St Louis, MO
Posts: 36

obviously i try not to breathe any welding fumes, just wanted to make sure that was normal. im not welding anything that needs to be strong, just good enough to hold together

Last edited by cutter; 03-15-2011 at 08:16 PM. Reason: remove hacker link
Reply With Quote
Old 01-23-2009, 04:01 PM
DrBob's Avatar
DrBob DrBob is offline
I fear I'll do some damage one fine day
Join Date: Jan 2009
Location: New York
Posts: 1,423
Default Welding Aluminum

Hurricane, as has been said you are at the very top of your machine's capacity. I think you will have better results welding thinner stock.
You should be welding with pure Argon gas. If you do there won't be any appreciable smoke. You have to turn the voltage and wfs up to get out of short/circuiting or globular transfer to spray transfer. Instead of the 'frying bacon' sound you will hear a loud buzz. BTW you can only spray transfer in the horizontal position (not vertical or overhead).
Most find that pure aluminum wire is too soft to feed through your regular gun and switch to a spoolgun. This has the wire right in it and since it only has to feed a few inches it won't birdsnest. Other tricks I have learned are to increase the stickout a bit and to move faster than when welding mild steel.
Also turn up the shielding gas to as high as 30-40 CFH. As I said pure argon.
Not C25. As always, PRACTICE PRACTICE PRACTICE! I would also clamp your coupons (sample welds) in a vice and try to bend them apart. You might be surprised when some of those 'good looking' welds just fall apart because of poor penetration. Aluminum is such a good conductor of heat that it takes more heat than mild steel.
Good Luck
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Web Search:

All times are GMT -5. The time now is 04:45 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.