Mig weld aluminum?

hotrdd

hotrdd

XS650 Junkie
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Have a few pieces of aluminum that I want to MIG weld together. I've put the wire in the welder, reversed the polarity, turned on the gas and cranked up the voltage. But when I start welding the aluminum wire just melts and splatters all over without melting the thin aluminum tubing and without really welding at all. What am I missing? Do I need to preheat the aluminum first?
 
Are you using aluminum wire? You also need to have a spool gun as the wire is too soft to make it through the tubing to the gun. Another thing, to do aluminum you need massive amounts of heats aka amps.
 
I have aluminum wire and a miller 175 welder. The aluminum has no issue feeding to the end of the gun as long as I don't kink it to tight. Should I try cranking the voltage even higher?
 
what type of gas are you using?
100% argon is ideal for this! c25 or argon co2 are a no no pre-heating can help also.
what size of wire are you running? and liner size also?
make sure at minimum the tip size is the correct

does this wire your using share a liner if so get a liner for aluminum only
when prepping aluminum use brushed s sanders etc... for only aluminum mark them
i say this cause cross contamination = poop

what settings a re you trying to weld with currently ?
 
NC WELDS – thanks for the help, I obviously don’t do a lot of aluminum welding so I am using .030 aluminum and a fixed gas. I do have dedicated brushes and grinder for cleaning stuff but the liner in the welder is the same one as I use for steel. I’ll have to check when I get home tonight but I just kept cranking the voltage up until I was at least ¾ to max.

The aluminum welds don’t even seem to hold they just spatter or melt and roll of the aluminum as if the stuff I’m welding isn’t even the same metal or getting hot enough. I can try to pre-heat tonight and see if that helps.
 
Do you have any idea what alloy you are trying to weld? I'm assuming the wire is most likely 4043. Melting points can be as much as 150 degrees apart. That's usually when the pre-heat helps the most, but aluminum conducts the heat away so fast, especially with a large section, that it's hard to keep the heat up in the area you are working. You may find that with a good pre-heat you can bring that amperage back down a bit.
 
i know that aluminum takes a pretty high heat but if the wire is melting before it actually "welds" it sounds like your wire speed is too slow for the volts. just a thought before you go spend more money on a new liner or anything else.
 
Will try some pre-heat tonight. Bit it will be interesting as aluminum transfers the heat so fast. Last night I tried playing with the wire speed and voltage but no much luck. And of course the aluminum rod is thinner than the 1/4" aluminum plate piece.
 
Will try some pre-heat tonight. Bit it will be interesting as aluminum transfers the heat so fast. Last night I tried playing with the wire speed and voltage but no much luck. And of course the aluminum rod is thinner than the 1/4" aluminum plate piece.
 
If you do go to your local welding supply store they may have temperature indicating sticks, they look like paint markers pens in size that would be a good way to determine
what the optimal pre heat would be if you plan on using the same material.

That way you'll be able record what was best by just a swipe of the temp stick they usually sell them in packs or individually i use them according to what customer specs are for pre heat or high temp range government and non government and Canadian certs also according per print.

This also apply's to material when things get to hot the composition break's down and things can get weaker/ more brittle and on the other hand it can add strength just helps determine optimal range.....
 
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Went out to the shop tonight and looked at the spool and it's .035" 5356 alloy aluminum wire. I tried to preheat the parts and then weld but it was spraying like it was a road flare.

What is the polarity suppose to be set at? Would that make such a huge difference?
 
reverse polarity and yes it can

switch the positive and negative terminals on the welder your currently using for this project and see if that helps
 
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Right now it is setup DCEN Electrode negative for flux core wire the other polarity option I have is for solid core wire. Thoughts?
 
you'll want that aluminum set on dcep reverse polarity (DC electrode positive) so reverse it to the solid core settings on your welder that should work
 
Thanks guys I'll take a read. Unfortunately I don't know what type of aluminum I'm welding as they are the broken shifter control on my motorcycle. I ended up sheering off the spring pin and thought welding it would be a better idea.
 
My forward controls are off of ebay and seemed to work great until it snapped the other day. I’d like to keep my current setup but it’s custom so changing to something else means building from scratch.
 
When I set the polarity back to normal the welding was a lot better but still a ton of splatter. I may need to try a different aluminum wire.

I'd love to be able to do better aluminum welds.
 

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