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Using a Rotisserie to Replace Floor Pans

67K views 39 replies 26 participants last post by  sporty 
#1 ·
I need someone to back up my logic for replacing floor pans on a rotisserie. I’m sure that one of you has done this before.





I plan to install new floor pans in my ’55 2dr Hardtop. I aligned the body gaps, doors, etc, with new body mounts while it was on the frame. Next I made 2 turnbuckle support braces that allowed me to keep the doors on while it’s on the rotisserie. The door gaps are the same now that it’s off the frame. The rockers are nice and solid, no sagging.



I cut the driver’s side pan out of the car (the passenger side is still on the body). I cleaned up the existing braces and welded patch panels on the braces where needed. I cleaned the inside of the braces and painted it with rust converter. I plan to paint over this with Eastwood’s Rust Encapsulator. I’m doing one side at a time to keep the car from flexing as little as possible.





I know the body is only supported at 2 points on the rotisserie, so it’s no in it’s natural position. But, I have the braces in the car to keep my door gaps consistent. So I'm suing the top half of the car as the supporting structure.

I plan to weld the floor pans in first, then put the body back on the frame, align the doors again if needed (body shims) for a sanity check, then replace the inner and outer rockers, lower qtr, etc. while it’s on the frame.

Here’s my question. Has anyone replaced floor pans while the car was on a rotisserie before? Does my approach make since, or should I attach the driver’s side floor pan to the braces first with sheet metal screws and place it back on the frame for final alignment and welding?

One body man from told me to cut the braces off the car and weld them on the new floor sections. After I build a one piece floor using the frame as a jig, drop the body down to the floor and attach it to the frame/floor to the body. If I have to replace the rockers and lower qtr panel sections this process seems like it would be difficult. Do I use sheet metal screws to hold the floor pan to the rockers temporarily?

What do you guys think? :confused:
 
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#4 · (Edited)
By no means am I a sheetmetal expert, but I've been warned many times from experienced metal guys that any sheetmetal replacement needs to be done on the frame that it will be on when completed. Can it be done on a rotissirie? Sure, and it's sounds like you're aware of the problems that it can create. Too much of a risk IMO.

Just my .02
Jay
 
#5 ·
Too much risk? While things can go wrong, if Matt completes it all and sets it back on the frame with the braces still on it, and shims all the gaps on the body mounts, it should be very close. I don't think I'd want to R&R the full width braces AND the floor with this method, but otherwise it should work.

To me, you can replace the sheet metal on the rotisserie if you think ahead. When the brace ends and the inner rocker are gone, then maybe not.

Just my opinion.
 
#7 ·
on frame/no frame

If you keep the door fit good I'd bet you'll have no problems at all...
 
#9 ·
New Floor

I came to the conclusion that installing the floor pans on the rotisserie was going to be a difficult task. The rear body mounts near the rear wheel wells proved to be difficult to locate. The floor pan flexed at least an inch either way. All the mounts from the curved long brace forward were easy to locate and to attach the floor pan to. The last body mount located in the cab gave me problems.

I decided to start from scratch. I removed what was left of the floor and the floor braces. I assembled the floor braces on the frame with new poly body mounts. I torqued the bolts to 25 ft-lbs. I used two wooden dowels to properly locate the floor to the frame using the stock transmission frame horns.



After taking several measurements for accuracy, I marked the floor pans and drilled the holes for plug welding. I welded the complete floor assembly while it was bolted to the frame.



Now for the nervous part… I rolled the frame and floor assy under the body. I lowered the body close to the frame and floor assy. Then I put the body on jack stands to hold it in place. I slowly jacked the frame and floor assy up to the body. I walked around the car several times to check gaps while I did this. The new floor fit perfect with a few minor tweaks with a hammer.




The whole process took me about an hour. The floor fits perfect. I attached the floor to the body with sheet metal screws. The body is held to the frame by the firewall body mounts and the trunk body mounts. I’m in the process of replacing the driver’s side rocker, followed by the quarter panel. As I replace the rockers, quarters, etc, I’m going to weld them to the new floor assy. This will finish the job.



This is definitely the easiest way to replace an entire floor. I’m definitely going to do it this way again on my next tri-five project. I’ll use the rotisserie after I finish all of my structural work. It’ll come in handy when painting the bottom.

I hope this might help a few of you out there with your floor pan replacement...
 
#11 ·
Huh.......I wouldn't have thought to do it that way, but NICE JOB! I've got my 47 2 door sedan on a rotissorie now. The floors are solid, but the trunk floor is swiss cheese. I believe I'll be able to R & R a trunk floor on the rotissorie fine, then, like you, be able to paint the u nderside on it. Thanks for provoking thought!
 
#14 ·
Matt,

Great illustrations!

I have two questions: 1) Along the front edge of the floor pans where and what type of weld are you using here, is is along the top, or is it underneath using some form of spot weld? 2) Along the back edge of the floor, is this all drilled out for plug welds?

I am debating a full floor replacement and am gathering as much info on this to help make a decision.
 
#15 ·
Sorry I didn’t answer everyone’s questions earlier. I haven’t been on the forum in a few days.

Mikeh57,

I did the complete floor in about 5 days. This included cleaning and welding new patch panels on the floor braces. My center brace was in good shape. I had to weld ends on the long curved brace under the rear seat. Then I welded the 2 floor sections to the floor braces that were bolted to the frame.

The actual installation of the completed floor/frame to the body took about 1.5 hrs. I did everything myself. If you have an extra set of hands, it might take less time. I was very careful about measurements while I built the floor on the frame. It might take longer to reattach the full floor to the body if you make mistakes during this process.

55PaulyT,

Along the front edge of the floor pan near the toe boards I will use a rosette weld, butt weld, or plug weld. For now I attached the floor to the body using sheet metal screws. Along the back I drilled holes for another series of plug welds. I used a 5/16 inch drill bit about 2 inches apart.

I really liked installing the floor this way. I’ve done it both ways now, inside the car and like this example as a one piece assembly. Most of my braces were in good shape so I was able to save a few dollars. Buying a one piece floor does save time but they usually cost more. If you’re worried about alignment then the one piece floor might be worth the price for simplicity.

I’m in the process of replacing my exterior sheet metal. I’m working on the driver’s side rocker/a pillar area. I’ll weld the rockers to the floor once I’m satisfied with my door gap and have my quarter panel section in place. I’m not going to make the mistake that I made on the tail pan. I need to grind a few welds to realign the tail pan with the trunk lid for a more consistent gap along the bottom of the trunk lid.


Matt
 
#18 · (Edited)
Incredible work for doing this by yourself!

I have one question about the full floor pan. Where did you purchase it?

I see the one from Danchuck @ $1300.00 versus the CARS on@ $2700.00 or so. I assume that the CARS is made USA and the Danchuck is China. I am not content with buying the China version. Any advice on quality floor pans/braces, etc would be great. :)

My '55 has lost inner and out rockers as well as all the outboard braces. I really only need about the floor area from the A pillar area to front of the rear wheel well and 8" (well to where the seat mount, which is gone) into the floor. I have to get the car acid dipped before I make a final decision.
 
#19 ·
I have sold many of the Taiwan complete floors here on TriFive with no complaints. The one that CARS list you must buy the inner rockers $65.00 each and they have a seam down the middle. It has been reported that they are also too short at the inner wheel well area where the floor mets the trunk. Check our listing in "Classified", we have them listed for $879.95 plus shipping.
 
#23 ·
+1 on Gene's 1 pc floor. Mine fit perfectly, comes w/ all the braces and inner rockers already installed.
I posted pics of the process some months ago, so I'll not bore everyone w/ a repeat.
I "cleaned" the old floor, inner rockers out w/ a plasma cutter, w/ the body on the frame.
Doing it again, NO WAY would I spend all the time to do a multi piece floor, braces, inners, etc!
 
#25 ·
Matt-

Thanks for the great pictures.

I am about to embark on the same project. My LH outer rocker has been removed, and am in the process of removing the entire floor. (I wish I hadn't cut that LH rocker out 5 yrs ago!) But, I am going to replace my entire floor just the way you did.

I made some braces to fit where the doors go, a door hinge to striker, does everyone think this will be enough with lifting it off of the frame? (RH outer rocker still in tact) :confused:

P.S. Mine is a 57 2DR HT

Mike
 
#26 ·
Intel 55,
I bought one side from CARS and the other side from OL’ 55 in PA. I usually buy my sheet metal every six months and pick them up at the Carlisle Car shows to save of freight. Plus, the companies usually give you 10% off. I found another company in Michigan called Tri-Five classics of Michigan who gives me 10% off of the CARS price. I didn’t buy an entire one piece floor because most of my braces were in excellent shape.

I’m sure the Taiwan panels would fit. I asked a few people who purchased their doors. They seem to be happy with them. The Taiwan panels are made from thinner sheet metal. I think they’re approx 20ga. Gene from Star City could tell you the exact thickness. The American sheet metal panels are 18ga. I found that a lot of the EMI panels fit great, then again some do not. I’m using all USA/Canadian made steel because of pride, not because of fitment. The car was originally made in the USA, I’m trying to keep it that way even if it cost me a few extra bucks.

MD-80,
If it were me, I would run a brace from the top door hinge directly over to the door latch and an angled piece from the lower hinge to the door latch on the qtr panel. The rockers provide most of the support for the body, especially when the floor is removed. You can make final adjustments to the qtr panel once you get the floor in place. You most challenging task is going to be lifting the body onto the floor with out the rocker in place.

Good Luck,
Matt
 
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