Discussion on Spot welder use in autobody

C

C10chas

Do you guys ever use spot welders in body panel replacement?
I picked up a Miller 220v spot welder a couple years ago on the cheap thinking I would use it on panel replacement etc. but to this point have only experimented with it and still use the mig to plug weld. Now, the plug weld is obviously stronger, but the spot welder has its advantages when it is able to be used: many spot welds can be done in a short amount of time, it puts less heat into the metal, thus reducing distortion and burning off less of our precious epoxy.....
thoughts?
 
You really need the "clamp" style spot welder to have an efficient weld. I've seen those other ones used that just hook up to your mig, sort of like a gun. You just hold it down on the metal and it welds...those aren't very effective and the welds are weak. You need that "clamp" style to get on both sides of the metal.

The gun one might work if you do the welding with a mig, grind smooth then come back with the gun to try to duplicate a factory look...but still even what it puts down doesn't look like the awful ones that were there from factory.
 
Guys, I been using a HTP Quick Spot II for about 4 years now and been very happy with results. It has alot of great adjustment for heat, clamping force,metal thickness. It also uses all the attachment's that HTP puts on the watercooled model they sell. It is 220 volts and has plently of power to spot just about anything. Joe
 
We use one in our production shop and there they are worth their weight in gold. I've installed two box sides in one 8 hour day many of times before and you would never know the difference. But not everyone can afford the 25,000 dollar machine it is. I still use the mig on home projects and jeremy has a good point about the one that attaches to your mig and trying to duplicate the factory welds, I wouldn't try welding a panel on with that alone though. There are even times I run into a spot I can't access with that big machine but its still worth it.
 
The only ones I have used that I would trust are 3 phase. They need the clamping force to get a strong quality weld. The ones that are in that category will definately, when working right, perform great. The Hirane we had at one shop dod poor welds, but you could not tell unless you tested them. I once welded a quarter on a Tahoe. When I was doing something else on the vehicle I noticed some poping and cracking. When I checked the area of the window opening I found several of the welds had broken loose. I then plug welded the whole panel on and never used that machine again.

That being said, I do own one of the 220 units that has the 2 contacts with a trigger on one. You have to put both contacts on the surface and weld. It produces 2 welds at a time. I have used it sparingly as I don't really trust it for structural welds, although I have not had any welds fail when tested as long as there is a good fit and it is clean.

Aaron
 
C10chas;13014 said:
Sorry guys, being more specific, I was referring to the 500.00 Miller 220v unit, it is hand held, but mine also came with a foot operated stand with a built in timer, probably for duct work or electrical box fab? If used for body work I would not use the stand/timer.
like this:
http://www.google.com/products/cata...&sa=X&ei=nB2JTp6dOcXj0QG14YkP&ved=0CH0Q8wIwAg

A friend of mine has a unit like that ( Dayton I think).
He used it for years doing sheet metal work, 16 ga galvaneal mostly.
The 2 things I noticed with it was the tip consumption and the diameter of the spot weld.
When he acquired a lathe he made a chuck tool that held the used tips so he could reface them.
We refaced a set of tips to do 5/16 spot welds .
I used it to put a pair of repair panels on a friends mid 70's Chevy pickup box.
It worked ok, but with the diameter of the tip it took a fair bit of time to get a good weld.
I was not sure how well it would tolerate the heat build up in the unit itself, so it was slow going.
 
ADTKART;13007 said:
That being said, I do own one of the 220 units that has the 2 contacts with a trigger on one. You have to put both contacts on the surface and weld. It produces 2 welds at a time. I have used it sparingly as I don't really trust it for structural welds, although I have not had any welds fail when tested as long as there is a good fit and it is clean.

Aaron

Aaron, are you referring to the type with two prongs, similar to the one in my link?
 
Novablue71;13003 said:
Guys, I been using a HTP Quick Spot II for about 4 years now and been very happy with results. It has alot of great adjustment for heat, clamping force,metal thickness. It also uses all the attachment's that HTP puts on the watercooled model they sell. It is 220 volts and has plently of power to spot just about anything. Joe

I like the looks of that machine Joe! One thing I dont like about the Miller I own is the tongs are too long and flexible giving poor clamping force.........but they do sell short tongs for it but mine came with the longer ones, probably 12".
 
They really have to clamp good and have a lot of amperage to make sound welds. Otherwise it's a waste of time. I'd say that I want as much weld quality in my resto work as in my collision work.
 
crashtech;13057 said:
They really have to clamp good and have a lot of amperage to make sound welds. Otherwise it's a waste of time. I'd say that I want as much weld quality in my resto work as in my collision work.

Absolutely, I agree.
I was wondering if your original statement (I think the only spot welders worth having (like a Hirane) are $$$.) was referring to collision work because of a need for production type work? Or because of strenght/quality of the weld?

I will have to perform my own testing with my Miller to determine if it is adequate. Is there an common strenght test I can perform on a spot weld?
 
Put one spot in a couple of test "coupons," then put one half in a vise and wrench the weld apart. If the weld takes some of the other panel with it when it breaks, it is a sound weld. If the weld comes apart, it is no good. You'll know it when you see it.
 
Well, that's just what I would have done, I guess I was expecting something complicated lol
thanks
 
C10Chas..... The one I was referring to is the "Lenco Panel Spotter" It actually has 2 heavy cables, one for each contact. The 2 contacts are put against the metal and a button on one of them is pressed to make the weld. The inside surfaces between the panels and the outside where the contacts are made have to be clean to make a weld. The panels have to fit perfectly and you have to have good constant pressure on the tips or you will not get a good weld at all. I have used mine for small panels that are fit very well and basically flat. Testing the welds on them showed good welds. On anything that is not a perfect fit I have doubts on the quality, and have had many burn thru instances. You can do a search on "Panel Spotter" to see what kind of machine I am talking about.

Aaron
 
Aaron, that definitely sounds like many variables have to be just right for a good weld to be made.
 
I believe that is why they are not endorsed by any of the manufacturers or repair authorities. It is amazing to me that they are still on the market.

Aaron
 
I have been using HTP quick spot 2 for some time and it works pretty well for me.It has got nice adjustment for metal thickness,heat and clamping force.
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projection welding
 
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