DIY Spot Welding Arms

[RichardB]

Anyone ever had a crack at making these?

https://www.mig-welding.co.uk/forum/threads/spot-welder-arms.62459/

Just trying to figure out what can be spot welded on the Spitfire when panel work starts, and I have to say this looks like a tempting idea. I've got a Clarke CSW13T ready to use, but the off the shelf arm options look eye watering expensive compared to the price of copper.

Given that the cars were almost completely spot welded, in theory with enough ingenuity in making arms, I should be able to use it to do the whole car, right?

[JohnD]

I hired a spot welder, to do some chassis rail repairs.  Had to wire it straight to  the fuse box in the garage as it blew 13 A fuses by !looking at them.  And when I fired it, 'er indoors said the the TV picture went all small.

Plug welding does most!y what spotwelders do!

Edited October 12, 2020 by JohnD

[ed_h]

Necessity is the mother of invention.   I had to weld the upper inner rear valence to the lower on my TR6.  Skinny flange between two tall panels.

These are just modified copper bus bars.

Ed

[img]http://bullfire.net/TR6/TR6-49/SDC13567a.JPG[/img]

[ed_h]

Just now, ed_h said:

Necessity is the mother of invention.   I had to weld the upper inner rear valence to the lower on my TR6.  Skinny flange between two tall panels.

These are just modified copper bus bars.

Ed

[img]https://bullfire.net/TR6/TR6-49/SDC13567a.JPG[/img]

 

[ed_h]

2 minutes ago, ed_h said:

 

 

[RogerH]

9 hours ago, JohnD said:

I hired a spot welder, to do some chassis rail repairs.  Had to wire it straight to  the fuse box in the garage as it blew 13 A fuses by !looking at them.  And when I fired it, 'er indoors said the the TV picture went all small.

Plug welding does most!y what spotwelders do!

Hi John,

my garage CB kept tripping with the spot welder. But it wasn't the current on its own. I think heat was building up as it would do one or two but not the third.

I ended up using a very long cable to get to the 60amp Cooker socket in the kitchen. Even then I had to change the CB in the main fuse board to a 'C' rating rather than the 'B' for normal domestic.  It worked but I still had to do plug welds to finish the bottom of the TR4A sill as the TRailing arm got in the way fo the arms.

 

Roger

[RichardB]

Definitely not a sensible idea to run a spot welder through standard household wiring. A fuse doesn't necessarily blow at 13A, it might actually blow at say 21A, by which point a cable might be well on its way to melting.

Great idea Ed, that looks like a really good amount of reach.

Since posting I found that chinese sellers have started selling spare arms on ebay for very low prices - eg link - which is arguably in some cases cheaper than I can get the copper for! Not sure if the internal diameter on my spot welder's arm mounts is 18mm or 20mm, but even if it's the former I guess it shouldn't be difficult to get them turned down a couple of mm.