Joggling?.

[Myles1970]

You do the best job you can do within the limitations that are set for you. I’ve steered away from lap/joggled joints, but I have the luxury of an enclosed garage and I’m not under pressure for time. IMO the pinnacle is tig welded butt joints, but as of yet I don’t have the skills (or the patience). I may be prejudiced against lap joints having seen the results of lap welds (they may have been plated repairs) where the hidden excess metal has corroded unimpeded. There are many spot-welded seams in the average car from the factory, but these always seem (see what I did there) to be the first places to rot, going largely unnoticed - it’s not until the paint starts bubbling in plain sight the the owner takes action.

Anyway, this is your project, and your keeping a classic on the road a little longer by which ever means are available to you. I’m convinced you’ll take whatever means necessary to stave off the rot and maintain the structural integrity of that little GTI for a few more years to come.

If you’re concerned about moisture ingress, maybe try sealing each joint with fibreglass stranded filler, zinc weld-thru primer and seam-sealer. Just be aware that you’re effectively doubling the thickness of the metal, making the manipulation of any low or high spots afterwards that much more difficult

 

[tom2207]

I have never tig welded anything still on a car ,,,, ever .

 

[steveo3002]

i hope you are planning to epoxy the new metalwork , that helps seal any pin holes and wont be effect by damp , and wont be effected if any cavity treatment gets on it

 

[bricol]

I hear the theory many of the original joins on a car body are similar in effect to a joggled joint - two bits, or more, of metal side by side.

Difference being it was originally treated way better in production than you can hope to do DIY.

I did all my repairs with gasless wire until a few years ago - certainly not as easy as with gas shielded wire in the same old SIP, and definitely not as easy as with the welder I have now using gas shielded wire, but it's not impossible to do good butt welds. Took me a while to learn and to stop warping panels with too much heat, but that process would have been similar with gas shielded.

 

[keithski122]

I have never tig welded anything still on a car ,,,, ever .

Neither have I, but that doesn't mean its not a better way of doing butt welded joints.

 

[tom2207]

Neither have I, but that doesn't mean its not a better way of doing butt welded joints.

why would it be ,,, ?
every days a school day .

 

[keithski122]

I've never done tig welding but form all the hot rod builders that I've seen they say that mig puts too much heat in the panel and the weld is harder than tig so you cannot work the weld afterwards. This is from people that do repairs that need little to no filler after repair so not people that are patching up and old banger.
Someone I suggest following on instagram is cornfield customs or bespoke_coachworks its amazing what they can do with metal.

 

[tom2207]

I've never done tig welding but form all the hot rod builders that I've seen they say that mig puts too much heat in the panel and the weld is harder than tig so you cannot work the weld afterwards. This is from people that do repairs that need little to no filler after repair so not people that are patching up and old banger.
Someone I suggest following on instagram is cornfield customs or bespoke_coachworks its amazing what they can do with metal.

tig isnt a magic bullet as most folk on you tube and tv would have you believe , a good tig weld isnt any better than a good mig weld , and on cars its a whole lot easier to get a good result from mig . and a lot more forgiving on used panels , if your getting fussy then the panel will be off the car and on the bench and then tig comes into its own , more heat input and a wider haz is not always a bad thing , it cools slower and you spread the load over a larger area ,,, and both will work easily enough post heat , as its only mild steel ...
now if your repairing alloy its a totally different game all together.

 

[Myles1970]

it cools slower and you spread the load over a larger area

Funny you mention it cooling slower, is that a benefit? Some people speed up the cooling with compressed air or a damp rag etc. (I don’t, but I’m far from an expert).
Btw, I see now what you meant about never having tig’d anything still on the car

 

[minimutly]

Funny you mention it cooling slower, is that a benefit? Some people speed up the cooling with compressed air or a damp rag etc. (I don’t, but I’m far from an expert).
Btw, I see now what you meant about never having tig’d anything still on the car

I would say thats not speeding up cooling - more preventing heat soak into the surrounding panel.

 

[8ob]

tig isnt a magic bullet as most folk on you tube and tv would have you believe , a good tig weld isnt any better than a good mig weld , and on cars its a whole lot easier to get a good result from mig . and a lot more forgiving on used panels , if your getting fussy then the panel will be off the car and on the bench and then tig comes into its own , more heat input and a wider haz is not always a bad thing , it cools slower and you spread the load over a larger area ,,, and both will work easily enough post heat , as its only mild steel ...
now if your repairing alloy its a totally different game all together.

Tom you should try tig, I am no tiggist but still find it so much easier and neater on thin sheet than I do mig. A tig set with a foot control pedal is a dream to use in comparison.

Bob

 

[tom2207]

Tom you should try tig, I am no tiggist but still find it so much easier and neater on thin sheet than I do mig. A tig set with a foot control pedal is a dream to use in comparison.

Bob

I find that the effort needed to get a decent result isnt worth the extra grief ,,, if im getting that picky I will lift the gas torch and do the job that way ,,, its not that I cant tig weld thin sheets , I just dont see the need when its on a vehicle at all ,,, its certainly no better tig welded than it is mig welded ,,, if I thought it was a better job with tig , I wouldnt use mig . Im not being argumentative , but if anyone can tell me why tig is better , Ill listen ,, convince me its better for on vehicle patching and I will change instantly ,,

 

[hotponyshoes]

Tom you should try tig, I am no tiggist but still find it so much easier and neater on thin sheet than I do mig. A tig set with a foot control pedal is a dream to use in comparison.

Bob

I'd agree except trying to feed filler and use a foot pedal between your knees while lying on the floor looking up at a sill is a nightmare.

 

[tom2207]

I'd agree except trying to feed filler and use a foot pedal between your knees while lying on the floor looking up at a sill is a nightmare.

and thats without the mud in your eye and the rust down yer jacket ,,, and those little drops right inbetween your fingers ,,, you know ,,, that white soft bit that hurts for days after ,,, lol