Spot Welding Pure Nickel (709A)

[flat tire]

OK I bought a 709A off ebay and try to weld some nickel strip also sourced off ebay. The 709A came with nickel plated steel strips which spot weld OK, but the nickel pretty much totally refuses to stick.

Here's the nickel used:
http://www.ebay.com/itm/0-1mm-x-7mm-0-0039-x0-275-99-6-Pure-Nickel-strip-battery-welding-10-ft-roll-/221913880756?hash=item33ab1918b4:g:IwEAAOSwuMFUlKQG

The thickness of this metal is within the welder's specification. Is there some special preparation necessary?

 

[Wheazel]

I can not say what the probelm is, but I can say that I have had no problems with pure nickel.
I have used a riba welder and a sunkko 788 chinese welder. Both working well.

What are the symptoms? Is the weld current not strong enough? Got any pics of the actual welds?
How large are your electrode tips? 0,1mm nickel should be easy to weld.

Can you weld the nickel on the nickel?

 

[spinningmagnets]

The current is flowing between the two probes through the nickel strip, and almost none is flowing through the cell-tip. Since you shouldn't put a spot-weld onto the center of the cell-tip, drill a hole there. Then, put one probe on the actual cell tip, and the second probe on top of the nickel strip. This is just a suggestion, I have never done this, and doing it may damage the cell (I don't know).

This is why so many nickel strips for battery pack busses have a slot over each cell tip.

The distance from one probe-tip to the other, through the cell-tip, is shorter than the current flowing through a shallow path, passing only though the strip, around the slot. You can make a slot with a dremel using a thin abrasive disc. Try a slot that is the length of the cells diameter, and see how it goes.

Another similar option is to cut the nickel strips into two long and thin strips (infinite slot), and that way, the only way for the current to get to the other probe is to go through the cell tip. This would result in two spot-weld per pulse (one under each probe).

 

[RootedSuperuser]

With my 709A and .015"*8mm pure Ni, I use full power with the handheld, you must use full power, there is just too much loss in the cable.
Using the machine welding, I'm at 6P & 4.5C and get perfect welds right through the strip (.015"x8mm) without a slot.
Also, don't use copper wire as the replacement tips, purchase the copper/aluminum tips, they don't oxidise as much and don't stick if you use too much amperage., current flow is better.
PRESS HARD, going easy here will produce poor results.

The 709A is rated for:

 

[pasc2003]

With my 709A and .015"*8mm pure Ni, I use full power with the handheld, you must use full power, there is just too much loss in the cable.
Using the machine welding, I'm at 6P & 4.5C and get perfect welds right through the strip (.015"x8mm) without a slot.
Also, don't use copper wire as the replacement tips, purchase the copper/aluminum tips, they don't oxidise as much and don't stick if you use too much amperage., current flow is better.
PRESS HARD, going easy here will produce poor results.

The 709A is rated for:

tank-you for explain how-to picture