[ryanjames170]

is anyone on the fourm here versed on TIG welding aluminum with helium?

[pgk]

I gave it a go a couple of times, used UHP Helium DC "Can't remember how many amps but it wasn't that much" on some 1/2" and was amazed at the penetration. Make sure it's clean, clean, clean, and at least in my minimal experience the bead didn't get shiny as it formed like it does when using AC also laying down a bead was much faster using DC over AC. I haven't done enough DC tig on aluminum to be even close to being a expert on giving advise, just my 2 cents. When I welded more often I used to hang out on the Hobart forum and there was a guy on there that worked for NASA and did a lot of DC on aluminum, some of his welds were just crazy good, just like everything practice practice practice..

[kiwi2wheels]

http://forum.weldingtipsandtricks.com/v ... inum#p8357

[Farmwelding]

I gave it a go a couple of times, used UHP Helium DC "Can't remember how many amps but it wasn't that much" on some 1/2" and was amazed at the penetration. Make sure it's clean, clean, clean, and at least in my minimal experience the bead didn't get shiny as it formed like it does when using AC also laying down a bead was much faster using DC over AC. I haven't done enough DC tig on aluminum to be even close to being a expert on giving advise, just my 2 cents. When I welded more often I used to hang out on the Hobart forum and there was a guy on there that worked for NASA and did a lot of DC on aluminum, some of his welds were just crazy good, just like everything practice practice practice..

And for your sake for now, nothing structural until your an expert.

[pgk]

I gave it a go a couple of times, used UHP Helium DC "Can't remember how many amps but it wasn't that much" on some 1/2" and was amazed at the penetration. Make sure it's clean, clean, clean, and at least in my minimal experience the bead didn't get shiny as it formed like it does when using AC also laying down a bead was much faster using DC over AC. I haven't done enough DC tig on aluminum to be even close to being a expert on giving advise, just my 2 cents. When I welded more often I used to hang out on the Hobart forum and there was a guy on there that worked for NASA and did a lot of DC on aluminum, some of his welds were just crazy good, just like everything practice practice practice..

And for your sake for now, nothing structural until your an expert.

LOL Yes your right and that will be awhile.

[JHenze646]

Could this be used to weld 1/8" material? Why or not?

[Olivero]

Since no one has mentioned it yet, I will.

You could DC aluminum it just requires a ton more of heat, the whole point of AC is the alternating current bombarding the oxidized layer on the aluminum and removing it. The oxidized layer is naturally generated constantly as the surface oxidizes when in contact with oxygen.

I believe that oxidized layer melts at like 1.5X or 2X the temp of the aluminum itself so when you finally manage to breach that layer, your aluminum is just burnt through or blobbed up unless you can control your heat really well, really fast. I guess you could just grind the layer off but you would have to be pretty quick as that layer builds really fast.

Why you would do DC instead of AC I don't know, I have heard of it but never looked into it, I guess if you don't have a machine that can do AC welding, then it would make sense but I think you would just be better of getting an inverter machine that can do AC & DC and getting a bottle of argon for TIG.

With a bit of beveling and carefull joint filling you can do 1/4" aluminum plate with a machine that can push 200 amps with straight argon, throw some helium in there and you might not even have to push 200.

Not saying it can't be done, just wanted to seem like a smart guy for once

[cj737]

Why you would do DC instead of AC I don't know, I have heard of it but never looked into it, I guess if you don't have a machine that can do AC welding, then it would make sense but I think you would just be better of getting an inverter machine that can do AC & DC and getting a bottle of argon for TIG.

I think there's a great many folks who don't have an AC/DC box, have infrequent need to weld aluminum, or simply are expanding their horizons to meet challenges. The balance of your post was very useful information for those who may not know about the properties of aluminum. Remember, aluminum MIG is DC too

[GreinTime]

Since no one has mentioned it yet, I will.

You could DC aluminum it just requires a ton more of heat, the whole point of AC is the alternating current bombarding the oxidized layer on the aluminum and removing it. The oxidized layer is naturally generated constantly as the surface oxidizes when in contact with oxygen.

I believe that oxidized layer melts at like 1.5X or 2X the temp of the aluminum itself so when you finally manage to breach that layer, your aluminum is just burnt through or blobbed up unless you can control your heat really well, really fast. I guess you could just grind the layer off but you would have to be pretty quick as that layer builds really fast.

Why you would do DC instead of AC I don't know, I have heard of it but never looked into it, I guess if you don't have a machine that can do AC welding, then it would make sense but I think you would just be better of getting an inverter machine that can do AC & DC and getting a bottle of argon for TIG.

With a bit of beveling and carefull joint filling you can do 1/4" aluminum plate with a machine that can push 200 amps with straight argon, throw some helium in there and you might not even have to push 200.

Not saying it can't be done, just wanted to seem like a smart guy for once

Actually, quite the opposite is true. You'll have much higher penetration with lower amps with DCEN and 100%He than you will with any manner of AR/He mix at a given amperage. You don't experience near the amount of warpage, as the overall heat input is lessened dramatically.

The parts have to be surgically clean, as there is no cleaning action at all when welding aluminum on DC. The puddle doesn't get shiny per se, and you are forcing rod in there. Try it some time, and cut/etch a weld sample to see for yourself. You can weld fine with AC over top of it, and root passes on large parts a common application for welding aluminum on DC only.

Sent from my VS995 using Tapatalk

[Arno]

Remember, aluminum MIG is DC too

But MIG cheats by being DCEP so it's always in 'cleaning' mode as far as the alu goes..

Which is also why alu MIG welds tend to be fairly shallow and spread out as it's lacking penetration in many cases.

Bye, Arno.

[pgk]

+1

Why you would do DC instead of AC I don't know, I have heard of it but never looked into it, I guess if you don't have a machine that can do AC welding, then it would make sense but I think you would just be better of getting an inverter machine that can do AC & DC and getting a bottle of argon for TIG.

I think there's a great many folks who don't have an AC/DC box, have infrequent need to weld aluminum, or simply are expanding their horizons to meet challenges. The balance of your post was very useful information for those who may not know about the properties of aluminum. Remember, aluminum MIG is DC too

[Olivero]

Actually, quite the opposite is true. You'll have much higher penetration with lower amps with DCEN and 100%He than you will with any manner of AR/He mix at a given amperage. You don't experience near the amount of warpage, as the overall heat input is lessened dramatically.

The parts have to be surgically clean, as there is no cleaning action at all when welding aluminum on DC. The puddle doesn't get shiny per se, and you are forcing rod in there. Try it some time, and cut/etch a weld sample to see for yourself. You can weld fine with AC over top of it, and root passes on large parts a common application for welding aluminum on DC only.

Sent from my VS995 using Tapatalk

It requires a ton of more heat. aluminum oxide melts at 3.762 * F Aluminum melts at 1.221*F so you will need double the amount of heat to get rid of the oxide layer into the aluminum. That's all I am saying.

I have never welded with 100% helium and probably never will. I keep a bottle of pure argon in my shop and that's all, I don't see a need for helium/ar mix, unless i Can weld any metal with it, in which case, I might get some

I have a Dynasty which is an ac/dc box, I might try it just to try it.

[Olivero]

+1

Why you would do DC instead of AC I don't know, I have heard of it but never looked into it, I guess if you don't have a machine that can do AC welding, then it would make sense but I think you would just be better of getting an inverter machine that can do AC & DC and getting a bottle of argon for TIG.

I think there's a great many folks who don't have an AC/DC box, have infrequent need to weld aluminum, or simply are expanding their horizons to meet challenges. The balance of your post was very useful information for those who may not know about the properties of aluminum. Remember, aluminum MIG is DC too

Yeah, I don't really do MIG, I am more of a sticker and a tigger which is what the OP is talking about, I wouldn't know a tip from a nozzle on a MIG

[GreinTime]

Actually, quite the opposite is true. You'll have much higher penetration with lower amps with DCEN and 100%He than you will with any manner of AR/He mix at a given amperage. You don't experience near the amount of warpage, as the overall heat input is lessened dramatically.

The parts have to be surgically clean, as there is no cleaning action at all when welding aluminum on DC. The puddle doesn't get shiny per se, and you are forcing rod in there. Try it some time, and cut/etch a weld sample to see for yourself. You can weld fine with AC over top of it, and root passes on large parts a common application for welding aluminum on DC only.

Sent from my VS995 using Tapatalk

It requires a ton of more heat. aluminum oxide melts at 3.762 * F Aluminum melts at 1.221*F so you will need double the amount of heat to get rid of the oxide layer into the aluminum. That's all I am saying.

I have never welded with 100% helium and probably never will. I keep a bottle of pure argon in my shop and that's all, I don't see a need for helium/ar mix, unless i Can weld any metal with it, in which case, I might get some

I have a Dynasty which is an ac/dc box, I might try it just to try it.

You're missing the cleaning part. There is no cleaning action with the DCEN, so you have to manually clean the parts. That was where my surgical clean part was meant to fill the gap, but I should have clarified further.

With no oxide layer to melt, because you brushed it off, it requires much less amperage than you would think to achieve WAY more penetration than you would think.

Sent from my VS995 using Tapatalk

[GreinTime]

Also, Ar/He mix will make your dynasty 200 weld like a whole different animal even on thin aluminum. Probably not worth the added expense, but at work, where we have bosses that pay for gas, we use helium on anything over 1/4" even with a Dynasty 350, as it makes consumable life go up because you can use lower amperage.

Sent from my VS995 using Tapatalk

[Olivero]

Actually, quite the opposite is true. You'll have much higher penetration with lower amps with DCEN and 100%He than you will with any manner of AR/He mix at a given amperage. You don't experience near the amount of warpage, as the overall heat input is lessened dramatically.

The parts have to be surgically clean, as there is no cleaning action at all when welding aluminum on DC. The puddle doesn't get shiny per se, and you are forcing rod in there. Try it some time, and cut/etch a weld sample to see for yourself. You can weld fine with AC over top of it, and root passes on large parts a common application for welding aluminum on DC only.

Sent from my VS995 using Tapatalk

It requires a ton of more heat. aluminum oxide melts at 3.762 * F Aluminum melts at 1.221*F so you will need double the amount of heat to get rid of the oxide layer into the aluminum. That's all I am saying.

I have never welded with 100% helium and probably never will. I keep a bottle of pure argon in my shop and that's all, I don't see a need for helium/ar mix, unless i Can weld any metal with it, in which case, I might get some

I have a Dynasty which is an ac/dc box, I might try it just to try it.

You're missing the cleaning part. There is no cleaning action with the DCEN, so you have to manually clean the parts. That was where my surgical clean part was meant to fill the gap, but I should have clarified further.

With no oxide layer to melt, because you brushed it off, it requires much less amperage than you would think to achieve WAY more penetration than you would think.

Sent from my VS995 using Tapatalk

Ooooh. Okay, I got ya know, yeah, well in that case, no worries

[Keith_J]

Wonder if HF could be added to DCEN to offer ionic cleaning? I know HF is used on AC to maintain arc stability during zero crossing but it isn't needed on certain wave forms like square wave where arc time at zero crossing is minimal.

Yes, I have done DC aluminum welding. Pure Ar too.

[ryanjames170]

Wonder if HF could be added to DCEN to offer ionic cleaning? I know HF is used on AC to maintain arc stability during zero crossing but it isn't needed on certain wave forms like square wave where arc time at zero crossing is minimal.

Yes, I have done DC aluminum welding. Pure Ar too.

no it could not as AC is the only current that has any kinda frequency in it due to the polarity changes

[Otto Nobedder]

...no it could not as AC is the only current that has any kinda frequency in it due to the polarity changes

A wave is a wave, whether it crosses zero volts or crosses 100 KV.

HF doesn't care what it's superimposed on.

Steve S

[ryanjames170]

...no it could not as AC is the only current that has any kinda frequency in it due to the polarity changes

A wave is a wave, whether it crosses zero volts or crosses 100 KV.

HF doesn't care what it's superimposed on.

Steve S

DC will not have any sort of sine wave to it unless something its wrong.. technicly AC to DC has a wave but a welder would not see it though, i mean if it could it would probably be the most advanced welder ever, i did some reading a while ago about this.. most voltages your average multi meater shows you is the average voltage ie 230V actialy spikes way above this sometimes double that amount. same with inverted DC voltage unless it has a capacitor then the voltage ripple is much much less this is what can separate that the cheap DC welder from the good one.. IIRC to have any kinda cleaning action it dose need to swap polarity's witch evan a DC voltage that did not have a capacitor would simply not due with out becoming a AC voltage..

[Poland308]

Thermal Arc 186 has settings and is rated for High frq DC.