Need good details on welding floor pans

[brtnstrns]

My father and I are going to be starting the welding for the floor pans in the 66 (Coupe) for spring break. I just need some good info/advice on how exactly to do this. I dont want to end up cutting huge holes in the floor and not having enough pan to cover it and what not. And what all is the best way to avoid problems and ways to do it without taking up too much time. Anything would be helpful...also we have a backpanel we need to weld in so if anyone knows about ways to do that please give me some input. ANy help would be greatly appreciated on both of these

 

[allcarfan]

its fairly simple....measure twice, cut once. Make sure you have about an 1" of overlap from the old floor pans to the new. Stitch weld every few inches...fill the rest of the seams in with body sealer.

 

[Lswhat]

put subframe connectors in first if u dont have them already if u dont want to then dont not open the door after u cut out the pans or u will buckle the body. just fyi if u dont know already

 

[RajunCajun]

Ii recently did full left and right pans in my 66 coupe and its quite easy lots of measuring and little cutting afterwards. I used 4.5" cutting wheels on a electric grinder that you can purchase from any of your depot stores, dewalt sells them for around 1.50$ each, not bad considering they cut about 10times faster than a air powered 3" cutting wheel. I Put the new pan in for temp and marked the outline took out and cut below that line quite a bit left the framerail and support sheetmetal on for time being, (there are spot welds there that have to be drilled) then got those off and straightend the bottom of my frame rail from inside and made sure its mounting flaps were nice and flat and put new pan in then put weights on it around the frame rail , before u secure anything you want to make sure that the frame rail is touching the pan good around all sides, may take some taking out and putting in and bending those flaps but its worth it let me tell u, had to use grade 8 allen head bolts and washers to snug mine down (poor fitting pan) then used sheetmetal screws with 5/16" head to hold down everything else. then tacked it up frame rail first and support then skip around, I would make sure that outer lip of the new pan near the door is correctly lined up all the way back though I took notice of that when I took out my old pan the lip follows these indents in the inner rocker ,
hope this helps some, msg me if u need more info
btw i had no doors mounted on my car no trans, no engine, jack stands holding near rear wheels on the axle tube, and roll up stands under front wheels in front. im putting on my subframes after i do my pans for a reason but thats my choice.

 

[fastcoupe68]

1. you will have to remove the seat risers. drill out all the spot welds on the risers. You can drill all the way through the risers and the floors because you are replacing the floors. 2. Use a sawzall to cut the floors out one side at a time. Cut the floor on the trans tunnel close to the bottom where the curve starts about 2 inches below where the seat belt bolt is. You will have to drill out all the spot welds along the inner rocker from the front all the way to the rear torque box. cut around the front floor support and the crossmember that is welded to the floor under the trans tunnel. after you have cut out as much floor as you can you will have to drill out the spot welds on the floor support and the xmember, then you can remove what is left of the floor. Next take the floor pan and lay it in the car so it sits almost to where its going to go. One recomendation buy good floor pans. American made the fit great ( american designers are the best) available from most good supply houses just tell them you want the amereican designers stuff, full length. trial fit the floors trim the existing floor until the floor sits where you want it but leave about a one inch overlap once you get it to fit perfect everywhere you will have to remove it once again to drill the holes for the spot welds on the inner rocker rear torque box floor support and x member with the floor in place you can mark the floor where your floor support goes and x member. drill hole along the lip that goes against the inner rocker about every 4 inches those will be for your plug welds you will also have to do this on the rear torque box and floor support and xmember and along the front lip where the floor meets the toe board. be careful when you cut the floor by the toe board you dont cut the lip under the floor. once you have all the holes drilled for your plug welds put hte floor back in the car and check your fit again you might have to do this a few times be patient. It's very important that the floor fits perfect before you do any welding or final cutting. Once the fit is perfect you will still have that one inch overlap along the trans tunnel and along the rear of the floor and over to the rear torque box. screw the floor in place with self tapping screws #8s work fine about 3/4 inch long. Now here is the tricky part you are going to take your sawzall and cut the new floor and old floor at the same time all the way down the trans tunnel every few inches stop and put a tach weld to hold the floor in place and just keep going till you get to the torque box you wiil have a perfect gap for butt welds go back and fill in the gaps till it is all welded. the reason not to leave the overlap is you will get rust underneathe the over lap, a very amueturistic move dont do it when you are all done with the welding on the trans tunnel weld all your plug weld holes. If you do it this way it is very clean looking and you wont have aproblem with rust again seam seal all the seams just like the factory did but only after you prime all your new sheetmetak let it run down all the seams and get in all the nooks and crannies (prevents rust) well i hope this helped you out if you have anymore questions I'm here. I have been restoring mustangs Proffesionally for quite some time and find this to be the best method. Just be patient and take your time. the final fit is the most important thing before you weld anything. Good Luck with your project!