Best way to separate pinch welds

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Jayman62

Jayman62

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Hi Guys,

I am trying to separate a quarter panel patch I bought. It's from a scrap car and has been cut with the trunk extension attached to the outer skin. My first thought was to drill out all the spot welds but as I was starting to do this I thought perhaps I should get suggestions from more knowledgeable folks. I need to use the trunk extension and the outer skin so i need a solution that will not damage either panel. Am I on the right track drilling out? I hate to make swiss cheese if there's a better way.

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Jayman62 said:
Hi Guys,

I am trying to separate a quarter panel patch I bought. It's from a scrap car and has been cut with the trunk extension attached to the outer skin. My first thought was to drill out all the spot welds but as I was starting to do this I thought perhaps I should get suggestions from more knowledgeable folks. I need to use the trunk extension and the outer skin so i need a solution that will not damage either panel. Am I on the right track drilling out? I hate to make swiss cheese if there's a better way.

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Yep.
 
Blair, Keysco, and Rota-Broach are 3 popular brands.
 
The trick is to drill out the spot weld and not drill through both layers.
 
People grind through the spot weld on the waste side to preserve the keep side.

A small pencil tip belt sander is reported to work well.
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Thanks for the suggestions, I really cant afford another tool so I'm going to try drilling the side that is the trunk extension with a regular drill then switch to a flat bottom drill trying not to pernitrate the outer layer. Maybe look at one of those spot weld drills but they look to pernitrate the both layers.
 
I just drill thru both sides then seperate with a hammer and a putty knife. Yes, you will have to weld the holes shut on 1 piece prior to welding the 2 back together but that's the fastest way when saving both pieces for me anyway.
 
You don't need that finger sander, it's just helpful. You can use the edge of a cutting disc on a die grinder or even a Dremel, whatever fits. You will see the color change right before you go through, then use an old putty knife and a hammer to pop the panels apart. Just be sure you're grinding on the correct side.
 
Jayman62 said:
Thanks for the suggestions, I really cant afford another tool so I'm going to try drilling the side that is the trunk extension with a regular drill then switch to a flat bottom drill trying not to pernitrate the outer layer. Maybe look at one of those spot weld drills but they look to pernitrate the both layers.
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I completely agree that the little belt sander isn't necessary, and if there's anybody that can relate to not bein able to afford something, that's me. But harbor freight has one for 25 bucks. Next time I go to Macon, I'm gettin one. If you decide to, I can tell you from using one to get the 80 grit. The 60 and 40 grits work like gangbusters, but wear out real quick. Whatever you do good luck with it. You'll get it done, regardless which method you use and you'll learn somethin new in the process and that's priceless.
 
You can get those separated with a $20 spot weld cutter bought off Amazon. I have cut a whole car apart with the 10 tips they give you. The trick is to keep the cutter centered on the spot weld, the cutter tends to walk around. I do this by center punching the spot weld with a sharp pointed punch for the collapse-able pin in the center of the spot weld cutter to ride in. Drill slow till the cutter is seated and lubricate with paraffin. Any old candle will do. Just poke the hot cutter tip into the candle. Use moderate drill speed till you get the hang of how it cuts, it is easy to drill through both panels so care must be taken until you become proficient. I would cut out some of the welds on areas of the panels you plan on not using. I use an old skinny small flat blade screw driver to separate panels and a flat blade pry bar to hold it open as I go. The small screw driver doesn’t bend when striking it with a hammer and the small tip not only gets into tight areas better, it cuts through easier cause of the small tip.
 
ch1ll said:
You can get those separated with a $20 spot weld cutter bought off Amazon. I have cut a whole car apart with the 10 tips they give you. The trick is to keep the cutter centered on the spot weld, the cutter tends to walk around. I do this by center punching the spot weld with a sharp pointed punch for the collapse-able pin in the center of the spot weld cutter to ride in. Drill slow till the cutter is seated and lubricate with paraffin. Any old candle will do. Just poke the hot cutter tip into the candle. Use moderate drill speed till you get the hang of how it cuts, it is easy to drill through both panels so care must be taken until you become proficient. I would cut out some of the welds on areas of the panels you plan on not using. I use an old skinny small flat blade screw driver to separate panels and a flat blade pry bar to hold it open as I go. The small screw driver doesn’t bend when striking it with a hammer and the small tip not only gets into tight areas better, it cuts through easier cause of the small tip.
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I guess all the ones I ever bought musta been pieces of CHIT, cause I ain't ever got um to work right. All the ones I ever bought got dull and smokes the tips of the blades blue on the second or third weld.
 
These type of drills might help

Theses are from dewalt.

Still cuts both pieces but small hole on keep side, removed metal on trash side.
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RustyRatRod said:
I guess all the ones I ever bought musta been pieces of CHIT, cause I ain't ever got um to work right. All the ones I ever bought got dull and smokes the tips of the blades blue on the second or third weld.
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I had better luck with the cheap harbor freight cutters.
 
I will say do not use an air drill, you will burn up bits left and right unless they are specifically made for really high speeds.
 
toolmanmike said:
The trick is to drill out the spot weld and not drill through both layers.
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I use an 1/8"drill bit thru the center of the weld then use a blair cutter and only cut through the side you are NOT using and then separate with a hammer and chisel . Now the piece you saved only has 1/8" holes not 3/8" holes. That's just me. There are other ways
blair cutting tools - Bing images
 
All the spot weld cutters are designed for slow speed. If they are dulling or turning blur tryout are running too fast. I made a tighter fitting center pin for the Harbor freight one and it works better with less wobble but you still want a pilot hole or punch mark
 
toolmanmike said:
Blair, Keysco, and Rota-Broach are 3 popular brands.
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Rotobroach is made by Blair. I use rotobroach cutters. Once you get the hang of it they take no time at all. I use them in a cordless drill on slow speed.
Sanding/grinding the weld down on the sacrificial side works great but is rather time consuming.
 
Use a spot weld drill and a spot weld spring center punch no Hammer needed. I take everything apart so every piece can be reused. Here I completely dismantled a front fender and reassembled it

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Oldmanmopar said:
Use a spot weld drill and a spot weld spring center punch no Hammer needed. I take everything apart so every piece can be reused. Here I completely dismantled a front fender and reassembled it

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I remember when yall dood that one. That was a good job!
 
I have removed spot welded parts before just to sandblast them. Sometimes you just cant get to what you need to without taking it apart.
 
The belt sanders are worth their weight in gold imo. Plus you can get the belts in scotch brite form for removing seam sealers and other stuff. Ive used the crap out of mine. But spot weld bits are just as effective

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