Spot weld/install new inner fenders

[72Charger72]

I have my charger down to bare metal and its time to start
Replacing the inner fenders and floor.
I've tried looking up videos on installing but no one
Is showing the exact process?
Do I need to drill holes for the spot welds or just burn a new spot
Into the panels? I bought a spot weld tip for my mig from Eastwood or

Thanks!

[68RT440]

If you are installing new panels then you will need to drill holes in the pieces and plug weld them. The spot weld tip that you bought is designed to keep your electrode the proper distance away from the panel, but the welding itself is done like a conventional MIG weld.

[72Charger72]

Thanks 68rt440 was hoping to avoid that ..i could have
Just drilled all the way through the spots when removing
Them and then just spot welded from the backside
And the welds would be hidden in the wheel wells?
Heres the link to the spot weld cone I bought and they show
Just clamping and spotting joins the two panels.
Also i guess i need to grind the coating off the
Panels where Im welding...i had a buddy who tried to convince
Me gluing them was the new way to go but thats an obvious
Cost cutting for insurance purposes way to go but he also said it cuts
Down on rust? Just can see gluing my car together lol I want to
Restore it tbe proper way.
http://www.eastwood.com/spot-weld-kit-with-3-8-inch-cutter.html

[Dreamcar]

I'm doing the same type of job. You don't need the spot weld thing from Eastwood. Just drill holes in a test panel and practice with different welder settings in the same position as you will be on the car. Gravity will make a difference depending on whether you are welding down or upwards. For the holes, I try to use an air punch I bought that makes the correct size hole (I can't remember the size right now)

If rust is your worry, use weld thru primer on the mating surfaces of the two panels you're welding together (after cleaning those areas down to  bare metal). Once the panels are primed with weld primer and in place, remove the weld primer you see through the hole you made in one of the panels so your weld on absolutely bare metal. When your done, use some seam sealer where you can. 

[72Charger72]

Thanks Dreamcar I had already bought the Eastwood cone so Im going to test the procedures Eastwood shows in the video just for shiats and giggles and will post the results. Seems a lot easier just to prep the surfaces and weld.
I was going to do it last night but ran out of gas for the mig. Getting some more today.
And I bought the weld through primer earlier because I knew I would need it.

[Troy]

That Eastwood spot attachment only works on their welders. I had one and it wouldn't fit the gun on my Hobart (Miller part). I just learned to do it without. I use a 3/8" hole most of the time. I also grind them flat though so they no longer look like a spot weld. Depends on your desired result.

Troy

[charger_fan_4ever]

You can grind the welds smooth then use a punch same size roughly as factory spot welds and recreate the spot weld look.

[Dreamcar]

You can grind the welds smooth then use a punch same size roughly as factory spot welds and recreate the spot weld look.

But then aren't you making holes again? How does that work?

[Troy]

You can grind the welds smooth then use a punch same size roughly as factory spot welds and recreate the spot weld look.

But then aren't you making holes again? How does that work?

No, you just whack it with the punch to put a round dent in the metal.

Troy

[Dreamcar]

You can grind the welds smooth then use a punch same size roughly as factory spot welds and recreate the spot weld look.

But then aren't you making holes again? How does that work?

No, you just whack it with the punch to put a round dent in the metal.

Troy

Now I get...I may try that!!!

[72Charger72]

Well I tested the Eastwood method last night and maybe my mig is a little too small because I could not get it to spot weld the two pieces together.
Looking back at their video it is pretty thin metal they are working with. Probably 22 or 20G.... I may try some more testing tonight but it looks like I will be drilling lots of holes.
It does make a very nice spot weld though.

[Dreamcar]

Well I tested the Eastwood method last night and maybe my mig is a little too small because I could not get it to spot weld the two pieces together.
Looking back at their video it is pretty thin metal they are working with. Probably 22 or 20G.... I may try some more testing tonight but it looks like I will be drilling lots of holes.
It does make a very nice spot weld though.

I also did floors and inner fenders this year and I too have a small welder. It's likely not your welder, but the settings. For the floor, you're welding onto the frame rail, which is thicker than the floor.

Try finding a scrap piece that's as think as the frame rail to practice on. You'll like have to turn up the power on your small welder (maybe even all the way) and perhaps slow the wire speed down slightly. This will give the weld pool enough time to penetrate through the thicker frame rail material. Start in the center of the punched hole and work your way out to the edges of the floor pan to allow the weld enough time to penetrate the frame rail without you being on the floor material for too long (since it's thinner material). Also, if you don't have a good ground, trying to get a good weld is useless.

When you're putting two pieces together that are not as thick as the rails, you can maybe dial the power down and play with the wire speed to get it just right. I used to get a baseline before fine-tuning to my own preferences...

http://www.mig-welding.co.uk/calculator.htm

[72Charger72]

Well I tested the Eastwood method last night and maybe my mig is a little too small because I could not get it to spot weld the two pieces together.
Looking back at their video it is pretty thin metal they are working with. Probably 22 or 20G.... I may try some more testing tonight but it looks like I will be drilling lots of holes.
It does make a very nice spot weld though.

I also did floors and inner fenders this year and I too have a small welder. It's likely not your welder, but the settings. For the floor, you're welding onto the frame rail, which is thicker than the floor.

Try finding a scrap piece that's as think as the frame rail to practice on. You'll like have to turn up the power on your small welder (maybe even all the way) and perhaps slow the wire speed down slightly. This will give the weld pool enough time to penetrate through the thicker frame rail material. Start in the center of the punched hole and work your way out to the edges of the floor pan to allow the weld enough time to penetrate the frame rail without you being on the floor material for too long (since it's thinner material). Also, if you don't have a good ground, trying to get a good weld is useless.

When you're putting two pieces together that are not as thick as the rails, you can maybe dial the power down and play with the wire speed to get it just right. I used to get a baseline before fine-tuning to my own preferences...

http://www.mig-welding.co.uk/calculator.htm

Thanks Dreamcar heres the video I am referring too... http://www.eastwood.com/spot-weld-kit-with-3-8-inch-cutter.html
I dont think I will have any issues if I drill a hole first. And thanks for the info on wedling the floor pans that will come in handy...But there video shows them doing this without drilling. I had my welder set on 4 (highest) and speed 2-3 (1-10)
I was welding for a good 3-5 secs and couldnt penetrate the second panel. Ironically if I just did the same thing with a single piece of panel it would more than penetrate .
I was using the old inner fender panel scraps to test so gauge was 2x18...thats why Im thinking their video has be a light gauge.

[Dreamcar]

Well I tested the Eastwood method last night and maybe my mig is a little too small because I could not get it to spot weld the two pieces together.
Looking back at their video it is pretty thin metal they are working with. Probably 22 or 20G.... I may try some more testing tonight but it looks like I will be drilling lots of holes.
It does make a very nice spot weld though.

I also did floors and inner fenders this year and I too have a small welder. It's likely not your welder, but the settings. For the floor, you're welding onto the frame rail, which is thicker than the floor.

Try finding a scrap piece that's as think as the frame rail to practice on. You'll like have to turn up the power on your small welder (maybe even all the way) and perhaps slow the wire speed down slightly. This will give the weld pool enough time to penetrate through the thicker frame rail material. Start in the center of the punched hole and work your way out to the edges of the floor pan to allow the weld enough time to penetrate the frame rail without you being on the floor material for too long (since it's thinner material). Also, if you don't have a good ground, trying to get a good weld is useless.

When you're putting two pieces together that are not as thick as the rails, you can maybe dial the power down and play with the wire speed to get it just right. I used to get a baseline before fine-tuning to my own preferences...

http://www.mig-welding.co.uk/calculator.htm

Thanks Dreamcar heres the video I am referring too... http://www.eastwood.com/spot-weld-kit-with-3-8-inch-cutter.html
I dont think I will have any issues if I drill a hole first. And thanks for the info on wedling the floor pans that will come in handy...But there video shows them doing this without drilling. I had my welder set on 4 (highest) and speed 2-3 (1-10)
I was welding for a good 3-5 secs and couldnt penetrate the second panel. Ironically if I just did the same thing with a single piece of panel it would more than penetrate .
I was using the old inner fender panel scraps to test so gauge was 2x18...thats why Im thinking their video has be a light gauge.

I'm only a hobbyist but I would never spot welded without making a hole in one of the panels. I've never seen it done like they are doing it in the video, and I've read and watched lots of how too's.  The fact you're trying to go through two layers (with one being thick) with just a home mig welder if more than likely your problem. The frame rail is probably just too thick. If you had enough power in your welder to penetrate the frame rail properly, you would likely burn a big hole in the floor pan.

When I did my floor, I put in place and held it down with sheet metal screws. Then, I crawled underneath the car and traced out where the lip of the frame rail was, and any other necessary areas. Then I took the floor back out and punched out all the holes along the frame-rail contact area and along the edges and sides. I made sure to make as many holes for welding as there where factory spot welds. I even added a few stitch welds along the front edge of the floor pan from inside the car just for good measure once it was spot welded in place.

Also, because I was using a lot of heat like you seem to be doing, when your welding those holes shut, you may want to increase the wire speed to not have to have to keep the heat on for too long and end up burning an even bigger hole.

Like a said, try to find some practice pieces in the same gauges as the two pieces you want to weld together. Once the settings are set, it's just a matter of fine tuning.

Good luck. 

[72Charger72]

Dreamcar I was only testing this for the fender panels not the floor. And actually I was only testing because of their video....(rabbit hole) 
I can already see in the end I will end up drilling holes  but definitely thanks for the  insight on the floor pan!

[BLK 68 R/T]

Just a tip to pass along, get yourself a piece of brass, short chunk of 1/2" bar stock will do. You can hold it up to the backside of any holes you need to fill and it will keep the weld from growing and making a mess on the backside. Also helps when trying to fill holes or gaps by keeping the weld from trying to burn through the panel.

[Dreamcar]

Just a tip to pass along, get yourself a piece of brass, short chunk of 1/2" bar stock will do. You can hold it up to the backside of any holes you need to fill and it will keep the weld from growing and making a mess on the backside. Also helps when trying to fill holes or gaps by keeping the weld from trying to burn through the panel.

I second that. Copper works well too

[Dino]

My cheapo HF copper spoon works great!   

[72Charger72]

I spent the summer learning to weld mig and stick ....so I am new to this and I did get a copper spoon early on as recommended here by several members.
finished my rotisserie and mounted the charger over labor day. I guess the Eastwood video got me thinking if I could spot weld without drilling and there would be minimal grinding it would be an advantage. We learn everyday 

[Troy]

I have a Hobart dual voltage. Even on 110 I can burn right through overlapping sheet metal. Just crank the heat up to the total thickness (both pieces). I turn the wire speed down too so I'm not adding metal. If you're welding thin sheet to a frame rail you may not get that to work with a weaker welder. Making holes in the top piece is a little easier and aids in alignment. It's hard to make a perfectly round weld. The Eastwood piece is kind of cool (to me) because it focuses the weld puddle in one spot. If you're steady you can point the tip directly in the center of your hole and hold it there until it expands into the edges of your hole. Same result but harder to duplicate 100 times while you're being contorted into odd positions.

Also, I often use self tapping screws or Clecos to hold things tight. The holes left behind are small (much smaller than one left by a spot weld cutter or what you'd make normally). I had issues when welding them where the wire would hit one edge and fill the hole immediately - but only on the top sheet! I figured out that I could crank up the heat and just poke the tip through the hole. One zap and it closes it all the way through. Sometimes there's a little tail left on the back if I poked too far but usually it burns off. These are the last holes to fill after you've done your "spots" so they aren't technically structural.

Troy

[72Charger72]

Thanks Troy I am going to do some testing this weekend...thought it was strange I was burning through like crazy before but not now? I was running beads before though and not just spot welds and a much longer arc most likely? The new cone does keep the arc at a consistent depth/length.

[Troy]

Heat builds up fast over time. I can fill a spot hole in about a second. If you run a bead (especially a slow one) the whole piece will get real hot, real fast. Result: holes! By the same token, you may have to slow down over frame rails because they take longer to heat up. I'm no expert but I can generally tell from the puddle if I have too much heat (it's right before the puddle falls on the ground!).

Troy