Use a MIG welder to weld in new floor pans. Where you you guys place your ground cable for grounding the pan? Since it lays flat I don't know where to attach it on the pan when I weld. Sorry, new to welding here!

It doesn't matter where you place it, all long as it's conducting electricity. Curious, I've NEVER seen a welder which didn't give you a spring loaded clamp for a ground you bolt the ground electrode to though. You buy one second hand or something? go to the local hardware store and buy a clamp.

Before you place the pan in the car just tack weld a stud in a convenient place on the pan. Then you can cut it off after you are done.

you can buy a magnetic ground thing at harbor freight. IT allows you to use the normal clamp but you clamp it on a magnetic base that pulls the ground to the flat metal.

I used the door striker to get a good ground.
Worked like a charm and never had an issue, just gotta make sure that striker gets a good connection with the clamp.

I just threaded in one of the seat belt bolts and used that

I have a Lincoln MIG welder which does have a ground "clamp". I thought you had to put the ground clamp actually on the piece you were welding, but I guess you only need to place the ground clamp on any good ground place on the body because the floor pan is touching the body to connect the ground....is this right?

I used a few self tapping sheet metal screws also. Holds the new pan down tight to the old. Then cleaned off any paint and welded away :) Not sure if it's the correct way, but it worked (First time I've ever welded)

I have a Lincoln MIG welder which does have a ground "clamp". I thought you had to put the ground clamp actually on the piece you were welding, but I guess you only need to place the ground clamp on any good ground place on the body because the floor pan is touching the body to connect the ground....is this right?


Correct, the entire body is one big conductor, so you could actually conect to yoru firewall and have the current passing through the body to weld the trunk. Just find a good convienient position to attach it.

lower part of the rocker at the pinch weld seem.

Generally in Welding, You'd like the ground as close to the where You're welding as possible. That way it will tend to make a circuit, rather then charging the whole car.

Generally in Welding, You'd like the ground as close to the where You're welding as possible. That way it will tend to make a circuit, rather then charging the whole car.

On a physics/electrical stance, by placing the ground anywhere on the car, no matter where you weld "charges" the entire car. However, if you have a good connection anywhere on a car there isn't enough resistance in the distance of a steel chassis it wont make that much difference. However to minimize any potential problems with regards to questionable grounding points and welding points.