Resistance Spot Welding

[metalman]

Interested in hearing what equipment anyone may have/use and how it works for you on collision work part replacement.

A shop I worked at circa 1971-72 (some dirt is still older than me) had a resistance welding unit that had a pinch clamp and was capable of making 2 spots at a time with 2 hand held electrodes. It was 220V, had some power and It worked well. All I can remember is that it was in a white metal enclosure with a timer knob on the top. Never seen one like it since. Tested one once I think was Lenco brand and it didn't work for $hit compared to that old unit mentioned above.
Any old guys here remember anything about that old spot/resistance machine?

 

[crashtech]

All I ever saw was the Lenco two-handed thing back in the day. It did not impress. I'm in the market for one, since GM for instance has made them a requirement from model year 2018 forward. The ones that meet their standards are $$$$$.

 

[Chris_Hamilton]

Latest Pro-Spot models are north of $40K. Almost is a necessity now though with the various high strength steels. Some of them do not like to weld very easily or well. You can find used Pro-Spot's, Chiefs, Car-O-Liners, etc for anywhere from $7500-15k if you look around. I've only gotten to use them a little but they sure are nice for putting on a 1/4 and bedsides.

Oh and I've "used" that 2 handed Lenco model in the past. Might be fine for assembling steel boxes, but seriously lacking trying to do any effective spot welding on a car.

 

[DATEC]

Pro-Spot and don't look back. Their PHS-101 cordless rechargeble unit is bad-ass, the i5 is the cats ass if you got the coin.

 

[Chris_Hamilton]

Here is a used i5, wish I had the money. https://www.carolinacollisionequipment.com/used-auto-body-equipment/used-pro-spot-i5-smart-welder

 

[DATEC]

Here is a used i5, wish I had the money.https://www.carolinacollisionequipment.com/used-auto-body-equipment/used-pro-spot-i5-smart-welder

The only down fall is you need to have 3ph to plug it in but if you have that at your disposal in your shop then there is none better. For all others the battery operated one is the one to get, but these units are for the hard core that demand the best.

They are very easy to use especially the i5, it is automatic and can do multi layers and all will make every weld look and perform just like factory welds. I used them at my distributor's warehouse when I was looking for some new equipment.

I can see these units being used in a variety of uses other then automotive repair so they are a useful tool that can make money in the right hands.

 

[Chris_Hamilton]

While we are on the subject has anyone else noticed how hard it is to weld the various high strength steels that are out there? We do quite a few rebuilders for 2 different customers and most of what I get to repair the various jobs are used panels. I've noticed in the past few years that plug welding that stuff is getting harder and harder. Some of it doesn't like to weld at all. Last week was putting back together a Nissan Altima, 1/4 panel with used stuff and it was darn near impossible to plug weld some of the inner structure. It kept wanting to burn anytime the arc touched it, almost didn't matter with the heat range on the welder, was very similar to a plasma cutter almost. Very frustrating trying to get a decent plug weld on that stuff. Lately that has been the case on all the various cars I've worked on. Very difficult to get a clean plug weld, especially when the top piece is thin and the bottom piece is thick. Never used to be like that.

 

[DATEC]

While we are on the subject has anyone else noticed how hard it is to weld the various high strength steels that are out there? We do quite a few rebuilders for 2 different customers and most of what I get to repair the various jobs are used panels. I've noticed in the past few years that plug welding that stuff is getting harder and harder. Some of it doesn't like to weld at all. Last week was putting back together a Nissan Altima, 1/4 panel with used stuff and it was darn near impossible to plug weld some of the inner structure. It kept wanting to burn anytime the arc touched it, almost didn't matter with the heat range on the welder, was very similar to a plasma cutter almost. Very frustrating trying to get a decent plug weld on that stuff. Lately that has been the case on all the various cars I've worked on. Very difficult to get a clean plug weld, especially when the top piece is thin and the bottom piece is thick. Never used to be like that.

Every day....... GOD Dam steel....... newer Subaru's are very thin and blow holes and make chicken chit welds. The steel needs to be very clean front and back sides of the panels and need to be welded fast or the puddle will either blow up hitting the floor or will splatter molten sparks down the back side of your neck.

You really can't prep the weld areas with a grinder anymore either because you need every mill thickness of the steel you can get. Prepping a dented area with a grinder warps the metal too it is becoming a real PITA.

 

[DATEC]

A pulse welder would be a big help too. I've used Pro-Spot SP-5 and that unit is sweet. It welds extremely smooth with no splatter and just grab another gun and touch the trigger and it will change to whatever you have it set for like alum. or Silica bronze which is very nice to work with for the fish plate joints (panel seams).