HELP: Floorpan installation

[tcuuh]

After spending weeks under my car burning and grinding off all of the undercoating I have found many more rust areas than anticipated including a "swiss cheese" around the brake master cylinder. Therefore I decided to replace the floopan but no one had the critical area around the master cylinder and torsion bar cross tube. Luckily I found a local shop that had purchased an original complete Porsche floorpan (from the rear seats to the gas tank). They had it since the mid 80's and had only scavenged the front section around the gas tank. I got it last week for $250! I felt great about that, an original part at discount prices. Now the killer, since it is an entire floorpan I dont want to cut it into sections to install. I know Restoration Design sells them in halves with an overlap. If I cut this pan I would have to make a patch panel between the sections (never have MIG'ed before so butt welding is out). Therefore I will have to remove the entire floorpan and into the cross tube area. I was planning on welding some square tube stock across the sill plate and center tunnel for support before removing the original (my door gaps are perfect all the way around, even when I jack up the car, no closing of gaps!!!). Okay, so does anyone think I should provide support in any other area? Incidentally, where should I place my jack stands. Currently both front and rear suspension are out so I just have it supported by a small outer corner of the floorpan. This will get in the way during fit-up and welding. I also have the engine out and just about everything else (it's so easy to take apart, hope I remember how it went together).

P.S. I am going to buy a MIG welder and do rosette welds. To remove the old pan I was just going to drill through the body and floorpan (on the top inside the car) and not drill the new pan in those areas. This way I will be able to weld most of the pan from inside the car on top instead of laying on my back. There are some other areas it looks like I will have to get a spot weld drill to remove just the outer layer.

[Rot 911]

Personally I would cut the panel into the two floor sections and leave the center tunnel in place. I just see things becoming overly complicated, with serious alignment issues if you cut out the entire floor and center section. I would then only do one side at a time. Actually if it was me, I would only weld in the areas that I actually had rust and leave the good areas alone. Less chance of a screw up that way. And metal is metal if it isn't rusted.

[mb911]

Give me a call if you have a chance regarding what you are trying to do I am a welding instructor at a local college and we do that type of thing once in a while for car guys that are in class. so we have done a few right now we are working on a 56 chevy Email me privaetly for my number at mcfarlandb@gtc.edu

Ben

[DavidI]

Originally posted by mb911
Give me a call if you have a chance regarding what you are trying to do I am a welding instructor at a local college and we do that type of thing once in a while for car guys that are in class. so we have done a few right now we are working on a 56 chevy Email me privaetly for my number at mcfarlandb@gtc.edu

Ben

This is a great example of what this board is all about! The P-car family....of course run by the SCWDP

David

[targa80]

tcuuh:

I answered your e-mail. Since you have most of the heavy items off the car i.e. engine tranny suspensionparts seats. Why don't you make your life a little easier and spend a weekend building a rotisserie. Cost would be just under $200 for materials and it is a good place to practice welding since it only has to be strong and not pretty. This would allow you to weld on both sides while standing up. If you are interested let me know I can e-mail the plans I used.

[targa80]

I just noticed I have already sent you the info on the rotisserie. Never mind!

[Series900]

Utilize the rotiss for cutting/grinding away the old, blasting, priming the center tunnel b4 welding the pan. do not weld your pan on the rotiss. Put the car back on suspension, check all gaps, then weld. go back on the rotiss for grinding and finish weld any difficult areas. Chassis alignment will be affected by floor pan replacement, if the floors are rotted, the longitudal/rocker box is probably weaker also. The celette bench is the ultimate jig for maintaining proper alignment, or constantly measure and check gaps. I have seen some wild temporary "caging" done to hold targas/356 cabs together when replacing floors / rockers / longitudal's, these areas are the "frame" of the unibody construction, weld it skewed and you will fight for body panel, window sealing and suspension alignment. The rotiss works for isolated patching , not structural panel replacement.

[tcuuh]

Hey all thanks for the responses. Series 900 I need to get access to the front suspension area to weld in the pan into where the steering rack hump is. Where else can I support it from without flexing it too much. I will be welding in crossbracing across the door jambs, etc.