Spot Welder

[SHostetler]

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Hi,
Hope you all can help me with this. I'm wanting to build some slip joint folders. I think I want to spot weld the bolsters. So, my questions.....

1. In general, Do I need a 220 volt unit or will a 110 volt unit suffice? I'm thinking .040 ss liners and perhaps up to .125 bolsters.
2. Any brand/make preferred over another?

Did I miss anything? Any other info I need to know?

Thanks
Steve Hostetler

 

[Overmountain]

It depends on the resistance of the metals being used, and amperage of the machine I believe. Most of the machines should specify what they can handle thickness wise. I assume you are talking about a clamp style induction unit which actually melts the two surfaces using an electrical current between electrodes. There are a lot of concerns unique to this style of welding, electromagnetic field, splatter, etc. I only studied spot welding of the induction style briefly, but here is a good pdf from Miller for just about anything you wanted to know about spot welding. http://www.millerwelds.com/pdf/Resistance.pdf

Hopefully someone with some experience with the different machines out there can point you in the direction of a good one.

 

[Bill Burke]

If you buy a cheaper unit (harbor freight) then get the 220 volt. I have seen the cheap 110 volt units fail to make good welds repeatedly. That said I use a 110 volt mill unit that works perfectly and has for nearly ten years. tip shape has a lot to do with the success of the welds. bolsters and liner have to be clean and flat for best results. It is a bit of a pain to gt the bolsters matched side to side perfectly at first but just takes practice. type of steel don't matter but it has to be Iron based, ie... you can't do brass liners nickle bolsters