Classic cars forum & vehicle restoration.

[Ewart Cox]

I would like to invest in a spot welder. I have single phase power supply and wonder if this will give the results I require or whether the only way of doing the job properly is with a three phase power supply. Any suggestions or experiences would be appreciated.
Thanks

[Old Wrench]

A basic simple hand-held Resistance Spot Welder, seems a good deal for the small body shop and keen DIY restorer.

However, if you carefully survey the market, then you will quickly see the cost of the base unit is quite small, compared to the cost of the range of arms needed! This is one of the perennial tool problems! Whatever you have suddenly you need another bit to "do this particular job". In which case hiring is a much better and cost-effective solution.

Additionally, in order to create good welds, the two parts must be shiny bright metal, or the weld fails to penetrate correctly.

Good auto body shop Spot Welders have various microprocessor systems to adjust the time, the resistance and the current etc.

Consider, rather, using gas brazing: (See my earlier post on this).

By the simple expedient of drilling a small hole thru the new panel and burnishing the receiving panel and firmly clamping the two parts with Gorilla welding grips, superior joints can be achieved; and with care, they look, in appearance, just like rows of spot welds.

Using Oxy-Acetylene gas from suppliers such as Hobby Gas, the capital investment would be less for a much more useful and versatile bit of kit.

Single over three phase: Unless you are setting up a busy workshop and need a range of equipment where three phase is essential, then the cost is far too high. Far cheaper to use a phase converter.