MIG welding aluminum

[Mars]

Hi everyone,

This isn't really a performance question per say, but I think this is a good site to ask my question. There's not really a general tech section here, so I stuck this in pushrod performance. ? Move the thread as you will, I wasn't sure where this should go...

Anyways,

Question is about welding the "white metal" kind of aluminum like the stuff used in our upper and lower intake manifolds and such.

Can this stuff be succesfully welded using a spool gun, alum wire and the correct shielding gas? I remember a while back Mcgavin has welded a nice aluminum flange to a 3400 Upper intake and put a Eaton blower on there. Short of TIG how can something like that be acheived for the average "do it yourselfer" ? Maybe there is a better way ? Brazing ? If there's an easy way of welding that stuff, I would love to practice and learn how to do it.

Comments ??

Thank You.

[robertisaar]

MIG might not be the greatest choice, but it can work, if you're skilled...

the right feed rate and amperage will be the key in this situation... well, even more now.

[neo71665]

TIG would be a better choice but it can be done with MIG.

[IsaacHayes]

That is that durafix stuff, Ben got some IIRC and I'm not sure of his results on cast aluminum intakes... I can't remember.

I thought the main thing when welding aluminum was to have the right type of welder, one that can do aluminum (something with the frequency of the electricity, never read into it), and to have the part free of oxidation as just in the air aluminum forms a thin oxide coating. Stainless steel wire brush prior to welding and sometimes heating up the part really hot will help.

[RacerX11]

I have had decent luck welding cast intake parts with a Miller 185 MIG and spoolgun setup. Any 110V MIG doesn't really have enough amperage to do aluminum. By the time you invest in a decent MIG and spoolgun setup, you could buy a lower-end TIG setup.

The most important part of welding cast intake manifold parts is the prep work. Clean the parts extremely well. If the part is used, you should consider having the part tank cleaned at a machine shop prior to welding to remove any carbon deposits. Also, bake the part in an oven if possible (not the one in the kitchen). The cast aluminum tends to hold contaminants in the pores of the metal, and this outgasses during welding, contaminating the welds. Pre-baking the part will cook these contaminants out ahead of time. Lastly, pre-heating the part either in an oven, or in front of a torpedo heater, to about 200degF will make the welding easier, as the part won't require as much heat when first starting the bead. This applies to MIG or TIG process.

For MIG, use 4043 filler wire for cast versus 5356.

Marty

[AaronGTR]

^That's what I've heard as well. I'm by far not an expert at welding, but I asked one of the guys at the local welding supply shops about welding aluminum with a MIG and he told me you needed a spool gun setup, right shielding gas, and a MIG with enough power because aluminum takes more amps. That's why I didn't invest in a really high end MIG myself. I didn't have the money for more right now and I figured by the time I was ready to spend that much I'd just get a TIG.

[vejatabul]

I have welded cast aluminum and sheet/extruded aluminum with my MIG. The thicker the aluminum, the easier. Welding 14 gauge 6062 T6 is somewhat difficult...

[MidnightriderZ24]

You can get some really nice Al beads out of a small mig machine with a few tweaks. No spool gun needed!

First, pure argon, no mix. Maybe someone knows why, or if a mix will work, but I couldn't get it to.

.035 wire. The .035 wire is stronger and will be less likely to bunch up in the machine. When setting the feeder tension, go as low as you can that the wire will still feed. It's better to let it spin on the wire when it gets stuck than make a little birds nest.

Tip drilled out to .0625 (1/16, the smallest drill I had). Aluminum expands more as it gets hot, and will clog up in a .035 tip. They didn't have any bigger that fit the machine at the welding store, so made my own.

Keep the line to the gun as straight as possible. Again, less likely to bunch. wound up zip tying the line to crates that were about the same height as the machine all the way to 4 or 5ft from the work.

CLEAN. Kind of duh, but aluminum likes to be cleaned. Sometimes even baking the part can help. Pre-heating can be helpful on thicker or stubborn pieces too.

That's about it, any more advice or info would be great, but it's already done everything I've wanted it to do. It's my friends machine, he welded up some holes in his intake manifold and made intercooler piping. I welded 3 IC's together. I prefer TIG, but this is cheap and works good enough

[Mars]

I like the replies I've gotten soo far...

Thanks everyone!

[SappySE107]

Durafix didn't work for me, but I was using MAPP gas and left the stuff at the shop. They didn't do it right, but either way keeping a manifold hot enough to work the Durafix stuff is just a huge PITA.

Scott welds aluminum with a 1960s MIG setup so I know it works. You really have to clean/bake the manifold a lot to get the oil out, and when I was having him fix the cracked uppers i would grind a groove where the crack was as well. The aluminum is pourous and sucks in oil/dirt, which will contaminate the weld. Since I have no welding experience, I cannot say how hard/easy it is or any specifics.

[no_doz]

im not sure what gas we were using but in college they had us mig on aluminum, depending on the thickness though its very picky about the machines settings & tig is a lot easier after you learn it initially (the whole pedal thing sucks ass at first but once you get used to it really isnt a big deal).

yes you can-but its going to require some...practice.

also you need to make SURE its wire brushed off any areas that the weld will be touching immediately before welding, & make sure that the brush has ONLY been used on aluminum & nothing else (a brush used on steel or other materials will result in contamination & a shitty shitty weld) & that you get the proper flux. also, its been 3 years but if i remember correctly you will want brass wire brushes, the little kind about the size of a tooth brush. REMOVING IMPURITIES WITH THE BRUSHES & FLUX IS VERY IMPORTANT-brush first, flux right after-& weld. if not your welds will most likely be horrendous.

dont just hop right in on something you care about-practice until you are 150% comfortable & confident that you can do it properly-if you have any doubts...practice more!

[geoffinbc]

I am a welder for a living so I can offer some tips.

You will be able to successfully weld aluminum with a welder such as a Miller 251 or 252, It has a spool gun connection. You wont need any more than that for at home use where production is not an issue. A spool gun is not a requirement either. But if you do use your standard MIG whip it helps to have a short one and you will need a nylon liner for aluminum and the correct drive rolls and a tip with a larger opening does help. It jams easily so that is why spool guns or push/pull guns are the norm in a shop.

You will also need a 100% Argon gas and a SS wire brush for aluminum only. There is no flux needed, but they are available.

When welding ALWAYS PUSH the puddle, even when going downhand. Making very nice welds that mimic a TIG bead is not that hard. When you find a setting you are comfortable with then begin welding. When the crater is full you will hear a distinct sound change to a crackle. Move forward about 1/4" and listen again for the crackle and repeat again. The further you move forward every time the crater is full the more time it will take for the next to fill and the larger the bead will become and the further the overlying whips will appear.

[pocket-rocket]

I know betterthanyou already covered what you need, but I found this browsing around on youtube.

http://www.youtube.com/watch?v=KCxGeyJvQsU