Mig welding aluminum

Jason_alex · Sat Dec 20, 2014 2:52 pm

Hey guys I am trying to weld some 6061 aluminum in a t-joint together with 5356 wire both are 3/8" running miller matic 251 with a 30A spool gun, 27 cfh 25.5 volts and 650 is what the wire feed is reading out, using a pushing when i weld one side and bend it back it just pops loose on the bottom and cant even tell it was welded hardly. any ideas? This is clean aluminum.

WerkSpace · Sat Dec 20, 2014 3:27 pm

Are you electrode positive? DCEP
http://www.red-d-arc.com/pdf/Millermati ... Manual.pdf

Jason_alex wrote:Hey guys I am trying to weld some 6061 aluminum in a t-joint together with 5356 wire both are 3/8" running miller matic 251 with a 30A spool gun, 27 cfh 25.5 volts and 650 is what the wire feed is reading out, using a pushing when i weld one side and bend it back it just pops loose on the bottom and cant even tell it was welded hardly. any ideas? This is clean aluminum.

nickn372 · Sat Dec 20, 2014 3:33 pm

What size wire? 3/64" (.045")? Your voltage probably needs to go up and your wire come down a little. You need to be in spray transfer for aluminum. A pic would help if you can but knowing your wire size will be a huge help.

Jason_alex · Sat Dec 20, 2014 4:09 pm

The wire size is .035 voltage is not at 26.9V and 650 on run speed.

Jason_alex · Sat Dec 20, 2014 4:12 pm

It took a fair beating to get it to brake but it did brake.

nickn372 · Sat Dec 20, 2014 4:42 pm

I would make a switch to larger wire to start with. You will have more control over the settings. Also you may need to preheat the aluminum a little bit. You would be surprised at what 100-150 degrees of preheat will do for you. To me it looks like at the beginning of the bead it isn't penetrating because the heat is being sapped away by the conductive nature of the aluminum then when heat builds up at the end it starts to burn in better. I always try to run a little hot for what I'm working on but a preheat is a big help to on thicker material. Try those settings on some 1/4" and I bet you will be on the mark. Just a side note my regulator rarely passes 20 cfh. Still provides good coverage and stretches the tank a little further.

Jason_alex · Sat Dec 20, 2014 4:54 pm

Thanks,
How do you guys pre heat your parts I have seen where they say not to use oxy-fuel for heat.

from page 14 Don’t use oxyfuel gas cutting, carbon arc cutting or gouging processes, or oxyfuel flames to preheat.
These processes damage the heat affected area and promote the growth and hydration of the oxide film
present on the surface

http://maxal.com/files/QuickSiteImages/ ... 12_doc.pdf

nickn372 · Sat Dec 20, 2014 11:34 pm

I use an oxy/acetylene torch. It doesn't take much to get the pieces up to 150 degrees especially if it's just practice pieces. Your local hardware or auto parts store will have a temp gun for $30ish or less. A high quality one is much more but if all you are checking is your preheat temp you don't need any bells and whistles. That's how I get by and have had no issues.

nickn372 · Sat Dec 20, 2014 11:45 pm

I guess Maxal would have engineers that would be able to explain this one out and I'm sure eats probably written down more places than one. 9.99 times out of 10 it's gonna be a non issue. Jody even does a video using a big oxy fuel rosebud to preheat the parts to 250 degrees because they are really thick. But what do I know I'm just an old dirty farm boy with a welding business

Jason_alex · Sat Dec 20, 2014 11:52 pm

LOL, thats what I call hands on experience!

bigworm40 · Sun Jan 04, 2015 11:29 am

I'm glad I found this post and read through it. We have (ill get the details tomorrow) 110 Lincoln mig welder with a spool gun that no one has been able to dial in. As I have read through all the other topics learning how many migs are sold and set up as fcaw-s machines and finding out last week that the little mig was delivered with fcaw-s wire it clicked that our machine might be set up as dcen. But if someone could post some pics of some of there spool gun welds they have been able to achieve with a 110 and a spool gun that would give me confidence and the patience to work through getting it dialed in.

nickn372 · Sun Jan 04, 2015 1:45 pm

You will be very limited with what you can do with a 110 mig because you only have a max of 140 (?) amps. You most likely will not have the smoke for anything thicker than 1/8". You may be able to handle 3/16" with a thorough preheat but at max amps you duty cycle is in the toilet as well (like 10-20%). My spool gun is set up to run off of my engine set because I'm primarily a portable service. You will need to max out your voltage and adjust your wire to meet that for most of you projects. I would use .030 wire 4043 (will fit most applications). A 110 mig weld should not look much different if any from a 220 or 3 phase machine weld. It's just size and amperage capacity. Also you need to run DC if you are not. Make adjustments, practice, post some pics and we'll go from there.