Welding Floor pan

[dapper]

Hi Guys,

I am restoring, well I am trying at least to restore a Jaguar 1978 XJ-S V12 5.3L.

I need to cut some parts out of the passenger side floor pan.

I was wondering for legal purposes do you need to weld underneather or can you weld from inside the actual car?

The reason I ask was someone said you have to weld underneath. If so that will make it awkward. Not impoosible but awkward.

My other question would be when I have cut the rusty bits away, would you overlap the new metal to the existing floor pan or I think you call it a butt weld.

Advice much appreciated

Thanks Dave

 

[BChild]

Hi Guys,

I am restoring, well I am trying at least to restore a Jaguar 1978 XJ-S V12 5.3L.

I need to cut some parts out of the passenger side floor pan.

I was wondering for legal purposes do you need to weld underneather or can you weld from inside the actual car?

The reason I ask was someone said you have to weld underneath. If so that will make it awkward. Not impoosible but awkward.

Hi Dave

Given the choice I'd weld from above - provided penetration is good it shouldn't look much different on top v underneath

My other question would be when I have cut the rusty bits away, would you overlap the new metal to the existing floor pan or I think you call it a butt weld.

I'd butt weld - but only because I'd want to avoid any areas where water can get between the repair panel and the original piece and cause more rust

(I may not be correct as I'm still learning)

 

[Chris Stevens]

A rotten XJS is not something that a beginner should even think about attempting! Most of these cars will have serious corrosion in the area of the rear suspension pick up points, and in extreme cases the rear suspension can part company from the rest of the car due to this.

In answer to the original question though, any form of patching of something like a floor pan is likely to lead to more corrosion in future, and can only be looked at as a temporary type of "repair".................

 

[piman]

Hello Off-Roader,

there is no reason that a part repair to a floor pan is temporary given the earlier advice of but welding and sound painting afterwards. A full seam weld will be necessary of course.

Alec

 

[dapper]

BChILD, thanks for the reply and info.

Off - roader. I agree with you. But the car itself is not that bad. I have had it inspected professionally before I purchased it. It was insprcted by a Jaguar Garage Specialist. They restore cars. Just Jags.

The only bits that need welding are the

outer sills
Very small parts of the passenger floor pan.
Rear bottom wing drivers side..

Everything else is just cosmetic. The suspension mounts are fine. front Sub frame beam solid as a rock which is susprising as they rot like no tomorrow.

Its will need new interior, and bushes.

Engine was a none runner but I have that fireing and running nicely.

Thanks


Dave

 

[tux]

No reason at all from an MOT perspective why you cannot weld it inside the car . Naturally you'll need to make sure there are no pipes etc under where you are welding and remove any underseal etc.

My preference would be to butt weld, as with a little work the repair can be made very neat or even invisible, whereas an overlap weld will always be visible and creates a potential water trap.

 

[dapper]

Butt weld it shall be then.

Cheers Tux. Looks promising from the replies. Yes thats what it needs to do pass an MOT and be safe.

Cheers

Dave