Welding long body panels

Hi guys

Im about to tackle this job. The inside of the bottom of this body panel on my van is rotting away, you can't see it much because of previous body filler. I will have to cut away all the bad parts and replace them with this body panel I ordered from the US. I know the rust probably only goes up half the height of the new panel my question is where is best to weld this on? Should I use the lip on the panel to mate it with the lip on the body? or would it be better to us maybe the curve just under the lip? or is the flat part the best? also I'm thinking to use as much of the new panel as possible as I know its good metal, more painting I know but better metal.

the panel is approx 14 inches x 70 inches

 

And..........................................................?

 

in my not very expert opinion I would use the whole repair panel and weld on the flat part above the curve. spaced tacks to minimize distortion.

 

The panels are oversize for a reason, so you can trim them down.

Cut just above or just below the swage line as this is the strongest point, clean to bare metal with a fine resin bonded disc and establish a good earth.

make very small tacks after clamping securely and do not be tempted to make any long runs as this will distort the panel.

I would go below the swage line as it is easier to blend the panel in with filler and it is less visible then a welded repair above the swage line.

 

Personally I would only cut out the least you need to remove & cut your repair panel to required needs

 

Try and get that dent in the rear arch sorted first,hard to judge from your photos,panel look straight,but looks like you've a slight bow on the body,might be me

 

Ahh, I can see all of the post now

 

Thanks all. ye the panel is fine, think that's the GF head shadow. So I'm thinking of something like this or should I take it up a bit closer to the curve?

 

It'll be something like that,its not easy to see tbh,to much reflection,any chance of some shots from another angle?
That replacement panel,is that meant to go right up to the door?

 

It is yes but my van is the LWB version so its about 3ft short from the door, but I'm hoping it long enough to catch all the rust spots but I wont know fully until I cut open the body section in the picture.

 

step back take a photo of the vehicle

then go under neath and tak a shot toward the outer edge you can do it as i have done

need a better look underneath and also at side facing