TIG welding 3mm copper

[Kent]

Can I do this with std Argon shield an a reasonably low Amp setting? I don't want to rush to a new odd ball bottle of gas or a new TIG you see. Last time I welded copper it was mega thick plate with MMA and it was surprisingly great to weld. Any specific electrode I need or particular grind shape?

Just thinking of doing a homey on a fish head to feed out of the new filtration system I am currently building for one of the Koi ponds in the garden. Thinking of like that Fish that Chokolini did recent copper feed pipe will hide well and it will turn a nice green colour in time you see.

Next thing I am the lookout for some spare 3mm or so copper sheet

 

[backpurge]

3mm should be OK with argon, need to wind the amps up compared to steel
Same tungsten and electrode prep as steel

 

[Rrunnach]

Done loads of copper 3> using bog standard argon. Pre-heat wont go wrong, either.

 

[Maker]

I've tried welding copper (Not an actual weld, just a bead on a plate) and it took ages to make a puddle but when it did it made a huge puddle. You definitely need a foot pedal.

 

[Kent]

what sort of amps on 3mm then?

 

[Tinbasherdan]

Copper will weld nicely with tig, as said it needs a bit more heat, I can't remember off the top of my head exactly how much, last time I welded copper was about a year and a half ago! But I'm sure someone will be along to advise amps shortly

 

[Hitch]

Done a few bits and bobs, always used pure argon, running on DC with a red tungsten.
Give it all a clean just before welding.

 

[hotrodder]

what sort of amps on 3mm then?

Depends a lot on the size/mass of the part and preheat, copper has around double the thermal conductivity of aluminium so the heat soak effect with small pieces is even more noticable i.e. throwing, say, 160A DCEN at a small 3mm thick part is gonna get messy quickly. Large chunks of 3mm on the other hand and trying to tack the bits at 160A is gonna be boring, especially fillets compared to say butts with a root gap
Just keep turning the amps up until you get a weldpool in a sensible time and then be prepared to go like the clappers or turn the amps down/back off the pedal as needed

ETA i don't do enough copper to know if this rule of thumb i've just made up will work or not but i'm thinking that, tacking aside, 55 - 60A per mm is probably in the ballpark? Kinda like the 40A/mm rule of thumb with ally

 

[Kent]

Thanks Hotrodder,

On my limits really but I am thinking of trying something different than the norm and a challenge. Don't do much TIG, hardly ever worked with copper and I don't do arty stuff- bring it one eh it for me anyway so can afford to mess up.

I might go thinner thinking on maybe 1.5-2 mm ?

 

[hotrodder]

Certainly be cheaper, easier to shape and easier to shear sensible sized strips of filler neatly. That said some twin and earth cable works as filler wire, i believe it's C101 but obviously when colour match is important shearing strips from the parent is a safer bet. Neither of them are as good regarding porosity as the proper C1 copper filler which contains extra deoxidising elements

 

[Kent]

was just going to use cable, I want it to turn green

 

[Paul.]

I have a regular job making up some frames from 1.5mm copper, around 80 to 90 amps or so gets them done quite easily, use a thin sliver of parent material for a filler rod, and as said same set up as for mild or stainless, really nothing to it on thin stuff,

 

[Kent]

I have a regular job making up some frames from 1.5mm copper, around 80 to 90 amps or so gets them done quite easily, use a thin sliver of parent material for a filler rod, and as said same set up as for mild or stainless, really nothing to it on thin stuff,
View attachment 63764

Any chance you have some spare sheet you could sell me?

 

[Paul.]

Any chance you have some spare sheet you could sell me?

Customer brings it in sheared to size, all I've got is a tinfull of little triangles from the mitres,

For small pieces probably ebay is your best bet, last week I wanted a small piece to solder a patch on a tank body and just slit and unrolled a piece of 22mm water pipe.

 

[Rrunnach]

You could braze/silver solder, for that extra effect, would look good when the verdigris sets in?

 

[norlander]

 

[julianf]

Cheapest place for thin copper sheet is used hot water cyliders from eBay. Larger and easier to unroll than pipe.