Anyone using the spot weld function on the Powertig 250EX?

[Steve]

I'm doing a resto on a 1991 Honda CRX HF. I love this car. It gets 54 MPG on the highway and saves me a ton of money. I want to keep it on the road for as long as possible. It's got 380,000 miles on it (original engine) and its been my car for over 20 years. It is pretty rusty now but I have been attacking the rust and welding in new panels and metal where needed.

My question is, has anyone used the spot weld function of the Powertig 250EX?

My newer torch has no trigger so I will have to get one of those add on triggers. (I usually only use a pedal) Or I could use the factory torch.

Anyone ever use it? Does it do a good job? I've got to weld some new flooring and new rocker panels and a spot welder would be ideal. Was going to get a Harbor Freight spot welder but I remembered that I had a spot weld option on the Powertig.

[parkour]

geezer uses it.
http://www.everlastgenerators.com/fo...ght=spot+timer

[Steve]

geezer uses it.
http://www.everlastgenerators.com/fo...ght=spot+timer

Thanks. Guess I should have done a search. Looks like it works pretty good from what I read. Should come in handy when I have to spot weld under the car.

[ogorir]

I don't have a 250ex (yet) but plug welds are arguably stronger than spot welds. I'm looking forward to testing the spot welds the 250EX makes, but resistance welders leave something to be desired in bond strength in the automotive field. if you look closely at an american car from the late 60s to the mid 80s, there are a lot of redundant spot welds because about 1/4 of them aren't any good.

[Steve]

I don't have a 250ex (yet) but plug welds are arguably stronger than spot welds. I'm looking forward to testing the spot welds the 250EX makes, but resistance welders leave something to be desired in bond strength in the automotive field. if you look closely at an american car from the late 60s to the mid 80s, there are a lot of redundant spot welds because about 1/4 of them aren't any good.

You are right about that. Some of the cars I've been messing with have really poor spot welds. I think it may be due to the fact that they are done by robots who don't pay more attention to detail.

I would think that I would do a better job of making sure that the metal is clamped together before welding. Plus, I could paint the inside of say a rocker panel and spot weld it without affecting the paint too much. Less heat affected zone is what I'm talking about.

There is not too much in the instruction site about spot welding with the PT250EX. I guess I will just have to do a few to see how to do it. No real mention of settings in the instructions or anywhere that I can find.

[parkour]

Maybe it's a terminology thing, but I get the impression that someone might be talking about actually spot welding welding with the 250EX. The machine doesn't spot weld, it arc welds. The timer allows you to repeatedly arc weld for a very precise and consistent length of time. It's about making a lot of tack welds very consistently. The manual http://www.everlastgenerators.com/do...wertiggen2.pdf covers the spot timer on page 15; items 14 and 22.

If I misunderstood, and no one was talking about "spot welding" with the 250EX; please disregard my post.

Jody does this sort of thing all the time.
http://www.youtube.com/watch?v=wNM6w...ailpage#t=193s

[geezer]

Dedicated spot welders with tongs will give a better/stronger spot weld, I have run a few trial spot welds on the 250ex and it does a good job, keeping in mind that the spotweld is happening from the top down, not from the middle out as a dedicated spot welder will do,dialing in the 250ex is trial and error on scrap (amps versus time so you don't blow through the lower material.) once it is set the advange of having a timer is obvious as the spot welds are consistant. Another plus is getting into tight spots where the tong type won't manover. I use a small stick sometimes to press beside the weld area to make sure there are no air gaps, it helps,also spacing your spot welds and then going back in between them later helps with distorsion/warping.

[performance]

We do have people using tongs on the 250EX for this...It works fine and they use it for production welding.

[parkour]

Whoa, tongs? As in, resistance welding? Are we talking about basically shorting it out and letting it crank 250 amps through the metal pieces to be joined? If so, I was way off; sorry.

[performance]

It cranks out any amperage set.

[Paul Moir]

You forgot to smirk. Here you go:

[Jason]

This sounds very interesting to me.. I need a 250EX now so I can use this when I put the floor in my car.

[ogorir]

I would think that I would do a better job of making sure that the metal is clamped together before welding. Plus, I could paint the inside of say a rocker panel and spot weld it without affecting the paint too much. Less heat affected zone is what I'm talking about.

the clamping is the issue. it doesn't take much of a gap at all to make a poor resistance weld, just enough that the pressure from the tongs can't completely compress the joint. the big problem is you often can't tell that the weld is crap while you're doing it or afterward, it's only when you try to pull it apart that you can see that you only got a tiny little spot to actually fuse together. you can definitely screw up plug welds by filling the hole and not burning into the base panel, but you generally know when you eff that up while you're welding it.

another reason why the spot welds on production cars are sometimes terrible is they often use a single-sided electrode, so there's no additional clamping action. it looks like a 2-pronged fork and makes 2 welds at the same time. back in the day (the cars I have experience with) they were all welded by hand by a UAW worker in or around Detroit. no robots. little quality control. they look like crap, but the operators usually didn't skimp on randomly placed spot welds. I have a great picture of some part of a '69 firebird* that has about 35 spot welds, some burned almost through both panels of 14 or 16ga, in about a 4x6" area.

*I can't remember what it was for the life of me. I was thinking front subframe for a second, but that's all stick welded together. anyway, it was a big wide lap joint.
[edit] now I remember, it wasn't the firebird, it was a '63 nova convertable that was in the shop at the same time, and it was one of the convertable-only reinforcements. that was an interesting project. the owner bought a full supplementary frame to go under the car with big brakes, ect. we tubbed the rear end for I want to say 335/30r18s, last I heard he was planning on putting an LS1 in it. ran into money issues, so it got thrown on the back burner. it's probably still at my dad's shop, actually.