To Joddle or not to joddle my Midget floor pan

[Harry Worth]

Hi all,

still trying to figure out how to repair things. Just when I think I've got it sorted I get a curve thrown.

My Sprite project - An experienced restorer has advised I should cut the floor pan a few inches out from the transmission and join the new half floor to the remains of the old with an overlapped (joddled) joint. I can see this is more forgiving for cutting accuracy and ease of fitting. He's also advisesthat a butt joint although strong tends to induce fatigue failure either side of the joint. The other school is that a joddled joint is a bodge and it should most certainly be butt welded. As a beginner I'm swayed towards the overlap and joddle - the car isn't going to be concours or anything close but hopefully solid. The floorpan is also relatively thin (1.2mm) so again I presume an overlap is more forgiving. I've enclosed pictures - you can hopefully see the line where I'm intending to cut. (the grey primer is great for marking out in pencil)

Any thoughts

Harry

Apologies folks, I've posted this in the wrong section - still getting the hang of the site. Guess it should be under 'Techniques'

 

[peterd51]

Hi,

I will always overlap, although not by much. I did try a butt joint on a car floor once and I wasn't impressed with it.

When I was learning I used about 1/2" - 3/4" overlap and welded both seams but now I tend to cut it a bit closer, less that 1/4" (6mm). When the top sheet burns back it ends up close to the edge of the lower sheet with very little overlap to trap moisture.

Regards
Peter

 

[malcolm]

Personally I'd grind the spotwelds to remove the old floor, then plug weld the new floor in place. That's also the most forgiving way of welding the floor in - you can turn up the power and really zap the plug welds without much fear of blowing holes.

Otherwise if you need to weld sheet to sheet I'm with Peter.

 

[drjim]

Interesting - I need to weld patches into the floor of my 635csi and along both sides of the sill/floorpan junction. I had been planning to use angle plug welded to the bottom of the sills, and cut along the edge of the angle to do a butt weld to the floor pan - have intergrips ready for the job.

Main reason is to avoid having to do too much upside down welding, and so that the repair is visible for MOT purposes - don't want a joddled edge left for them to complain about/fail on.

So what's the issue you had with butt welding car floors????

 

[Harry Worth]

I'm a first timer taking lots of advice - trying to cut a relatively long length of floor pan to get a good butt fit sounds tricky whereas a joddled edge would be more forgiving. My plan so far is to joddle then weld and then flip the bodyshell over and seam weld the other part of the joddled edge - probably easier with a small car such as a Midget than a 635CSI.

 

[drjim]

I flipped my e21 track car while it was a bare shell, but this car has engine suspension etc fitted so I'm limited to getting it high enough to work under easily. If you can weld both sides easily by flipping it, then go for the joggled edge approach - it'll make life a lot easier.

 

[Harry Worth]

Many thanks gentlemen,

To joddle it is!

 

[Paul.]

Joggle is the proper term, not joddle, anyway thats the way to do it, theres a lot of concern on here about moisture traps on lap joints, but cars are all lap joints, buy some weld through primer and seam sealer and you can make a perfectly sound joint.

 

[Harry Worth]

Should have asked you first - Went straight to your posted pics of the inverted Frogeye you restored to see where your cuts were

Best regards

Harry

 

[marknotgeorge]

I've recently finished the front left corner of the floorpan on my TR7, and I did it using butt and plug welds. I did find it difficult to get the repair panel to fit, and had a few gaps. I suspect joggling might have made things easier, but I don't have one. I'm currently doing the left rear corner, and it's a bit easier this time, possibly due to having had a bit of experience.