Aluminium pulse mig

[Carsten S]

Hi,
I'm new on this forum, and i don't know nothing about aluminium.

I've got some 5356 (AlMg5) 1,0 mm wire, would that type of wire fit most regular aluminium plate and profiles? Cast is not important for most of my work.

As said, i'm quite new to aluminium. Ie. when is it too hot or too cold, it's quite difficult i think. Got a pulse inverter, is it possible to do uphill/downhill, or is it like regular steel spray transfer?
I gotta repair some old alum welding that have cracked, guess my best shot is to clean as much as possible, and give it a shot with the 5356 wire. Any thoughts?

Thanks in advance

 

[matt1978]

Pulse will be simerla welding wise to Spray arc, you need to Push it and have a really leading angle or else the welds will be Black and sooty.

Regarding the Aluminium you need to make sure it's really clean, put a lot of effort into this much more than you would when welding steel or stainless because Aluminium has to be spotless prior to welding or else you will get lots of Porosity.

 

[Sub-arc]

5356 is used as a general purpose wire because of the added strength the mag gives the wire. It is the easiest grade to push from the machine. A push-pull torch/machine will drive any grade of Al easily. A pulse mig is the best for Al and should give the best results.
5356 can be used for a lot of applications but if the job were safety critical in any way, you should find out the material and welding procedure (or not do it at all)

The vertical up/down will be trial and error. Adjust the amps/speed accordingly.
Clean out as much of the cracked weld as possible and as Matt has said, the cleaner the Al the better.

Welcome along by the way.
Do search in the forum for Pulsed Aluminium welding and you should get some more tips

 

[Lewis Medlock]

Hello Carsten, welcome to the forum

Just a few thoughts to add (an ill informed layman's experience of welding aluminium) to the good advice already offered.

Get stuck into a piece of scrap!
Play around with the welder and see what happens. Clean the aluminium just prior to welding because the oxide forms quickly I think, you didn't mention your shielding gas- you'll need pure argon. I find welding Ally more similar to dip transfer and positional work is no problem but that may be because I use pulsed AC plant (I'm thinking your inverter is DC?)

I've not worried with pre-heating but what has caused me trouble is an anodised (maybe but I'm just guessing) finish that I didn't fully remove. This resulted in pretty pinholes all along the weld bead.


My first dabble with MIG welding aluminium is in this thread: http://www.mig-welding.co.uk/forum/showthread.php?t=22582


Good luck, and please post your results in a thread so we can all learn from it

Jim

 

[backpurge]

I find welding Ally more similar to dip transfer and positional work is no problem but that may be because I use pulsed AC plant (I'm thinking your inverter is DC?)

My first dabble with MIG welding aluminium is in this thread: http://www.mig-welding.co.uk/forum/showthread.php?t=22582

How did you find the AC MIG, used it quite a bit in Germany a few years ago but have never come across one in the UK for some reason

Excellent thread on your repair, highly recomend anyone tackling an ally job for the first time to have a look at it

 

[julieanncharters]

if your going to be doing a lot of aluminum then i'd get geared up for it.
back chip tool of some description for cleaning out old or crap welds,
i use a 4" tct blade in an angle grinder really quick but also a scary bit of kit with out proper protection.
die grinders other option but to slow for me.
how thick a plate are you welding .
if its thin 3mm then stick with the wire you've got thicker could use 1.2 less feed problems.
only other point about filler wire if you use the wrong grade there is a colour difference which will show up on flattened bead or anodizing.
the 5356 your using will produce a bit of soot or "smut" as its called due to the high mag content
anything above 6mm i stick a bit of preheat on it.

 

[matt1978]

because I use pulsed AC plant (I'm thinking your inverter is DC?)



My first dabble with MIG welding aluminium is in this thread: http://www.mig-welding.co.uk/forum/showthread.php?t=22582


Jim

Hi Jim,

The unit shown in your thread on the Alu trailer repair is also DC not ACDC. AFAIK there are only 2 AC migs on the market, OTC/Panasonic & Elma Tecnik.

Unless of course you was talking about AC tig??

 

[Lewis Medlock]

The unit shown in your thread is also DC not ACDC.

Unless of course you was talking about AC tig??

Is it!

I had no idea and guessed it was AC because it sounds like a long wet fart when it's in pulse mode- like an AC TIG. Cheers for that Matt I really should try and digest the instruction book one day.

How did you find the AC MIG, used it quite a bit in Germany a few years ago but have never come across one in the UK for some reason

Excellent thread on your repair, highly recomend anyone tackling an ally job for the first time to have a look at it

Thanks BP, I made a comment on the thread about a good machine making the job easy and it certainly applies to the Fronius, all pre programmed and idiot proof as long as you know what type of wire and parent plate you're using. Any problems with the joint isn't the MIG it's the operator

I'm using 1.0mm wire in 1.2mm drive rolls at the moment as that's all I've got for aluminium, the grooves are different profiles for steel wires and I've only got 1.0mm drive rolls for steel.... It's a 4 roll drive system and they're £60 each plus VAT

Anyway, it's a great bit of kit and I'm really lucky to have the use of it.


All the best, Jim

 

[matt1978]

Nah it's DCEP. Cracking machine though

 

[backpurge]

Agree with you re Fronius, have used them on and off for best part of 20 years

 

[Carsten S]

Thanks alot for the welcome, and the quick and good answers For some reason i didn't get email notifications on new posts.

After grinding the old cracked weldings down and wipe it with acetone, the welding went straight forward. Some of it was 4 mm, and some 5 mm/6 mm in a t-joint. I was really surprised how much amps you need on the machine to get it going.

One place it got dificult was in the bottom of the section, water and dirt keep boiling behind the plates, and contamined the weldpool. Tried to preheat with a torch, but no luck. At last i make a plate that overlapped the old welding, problem solved

EDIT: Vertical downhill is possible without the weld gets black/soot or porosity.