Welding a outer 1/4 panel onto a car

[Murraym]

Good afternoon

This is my first post on what I’ve found a very helpful forum so thank yous.

I am currently restoring a 1992 vauxhall mk3 astra gsi. The car has been off the road for many years (2016 last mot) so it was in need of work.

At the beginning of the project I purchased a parweld xte171c mig welder, which has been a great to get the car to where it is. It’s had 2x sills replaced, front lower cross member and few bits here and there made from sheet steel.

For the sills/lower cross member I had a couple guys help out as I’d never done either sortve repairs before.

Now with a bit more experience I’ve made a start on replacing the drivers side rear 1/4. This is been a big learning curve, and has taken me a lot longer than it would someone with more skill/experience but I think am getting there.

I’ll attach some pictures to show where I’m at.

 

[Cobbler]

You’re brave, that’s all I can say. Good luck & keep,us posted.

 

[Murraym]

I’ve welded in a fuel filler repair panel and have had the outer 1/4 on and off I’ve lost count of how many times. All fits relatively nice, tomorrow I hope to weld the outer 1/4.

Any tips and tricks? Should I concentrate on any areas first? I assumed maybe the joint that’s visible by the back window, and what size drill bits for spot welds? How far apart should the holes for spot welds be made…

Lots of questions. Any help very much appreciated

 

[minimutly]

My advice, but I suspect it's too late, and nothing to do with welding - cover all glass with a decorators polythene sheet, inside and out, otherwise your grinding and welding sparks will burn spots into it all....

 

[minimutly]

Well done or work so far, try to at least replicate the makers spacing for spotwelds.
I did sills and rear arch repair panels on a mk2 Astra many years ago, then I went to investigate "bubbles" in the soundproofing on the boot floor - I should have checked these first - the floor had rotted all along the join with the rear chassis sections from the spring hangers to the back panel, I had to make new floor sections...

 

[Murraym]

You’re brave, that’s all I can say. Good luck & keep,us posted.

Thank you!

 

[Murraym]

Well done or work so far, try to at least replicate the makers spacing for spotwelds.
I did sills and rear arch repair panels on a mk2 Astra many years ago, then I went to investigate "bubbles" in the soundproofing on the boot floor - I should have checked these first - the floor had rotted all along the join with the rear chassis sections from the spring hangers to the back panel, I had to make new floor sections...

Thank you I will do!

Seems common issue among old vauxhalls

 

[Nomad]

Nice work !

I’ve not done a rear quarter but for other panels I use a lot of mole / vice grips of various sizes to hold panels tight together when I’m welding them.

You now have great access so fix anything that will become difficult when the new panel is in place.

My guess is the door & tailgate gaps will be most critical so pay attention when lining things up so those gaps stay right.
Watch out for other edges moving when you’re concentrating on the bit you’re welding.

Hope it all goes well

 

[Misterg]

what size drill bits for spot welds?

7mm works for me. I find 6mm too small. Poke a small 'pencil' wire brush in a drill through the holes to the panel below to clean off any primer before welding - makes for much cleaner welds.

Practice first.

 

[OJCar]

Paging @Blobber to the GM phone

 

[tom2207]

7mm works for me. I find 6mm too small. Poke a small 'pencil' wire brush in a drill through the holes to the panel below to clean off any primer before welding - makes for much cleaner welds.

Practice first.

and dont start in the middle of the hole , start at an edge then work across the hole with a flick up in the middle , you get a far better weld , if you start in the middle on smaller 5mm or so holes you can get a colder start and by the time the heats there the hole is full of weld so you dont get good joints , go up a click on the power and use a copper backer if you can ,,, basically if you have to grind a spot weld down its not hot enough ,,,,do some practicing off the car until your comfortable every time , clean both surfaces well ,,,
and welcome to the forum

 

[Murraym]

Nice work !

I’ve not done a rear quarter but for other panels I use a lot of mole / vice grips of various sizes to hold panels tight together when I’m welding them.

You now have great access so fix anything that will become difficult when the new panel is in place.

My guess is the door & tailgate gaps will be most critical so pay attention when lining things up so those gaps stay right.
Watch out for other edges moving when you’re concentrating on the bit you’re welding.

Hope it all goes well

No worries! I have a few to use, I’ve drilled a few holes and able to secure it with self tappers too.

Thanks for the reply I shall update when it’s on

 

[Murraym]

7mm works for me. I find 6mm too small. Poke a small 'pencil' wire brush in a drill through the holes to the panel below to clean off any primer before welding - makes for much cleaner welds.

Practice first.

Good advice.. I will take up on this. Thank you

 

[Murraym]

and dont start in the middle of the hole , start at an edge then work across the hole with a flick up in the middle , you get a far better weld , if you start in the middle on smaller 5mm or so holes you can get a colder start and by the time the heats there the hole is full of weld so you dont get good joints , go up a click on the power and use a copper backer if you can ,,, basically if you have to grind a spot weld down its not hot enough ,,,,do some practicing off the car until your comfortable every time , clean both surfaces well ,,,
and welcome to the forum

Cheers for the tips. I will have a few practise tomorrow with the panel I took off before committing to the new one.

Will update when done.

Thanks for all replies

 

[eddie49]

I’ve drilled a few holes and able to secure it with self tappers too.

You might want to use the Search box at top right to check out Intergrips and Cleco pins.

 

[Blobber]

Is it a genuine panel? Lots of clamps so you can do a trial run to check all your lines and to get/keep the seam tight when you weld, can you borrow a spot welder? Nice to see an original non messed about Gsi

 

[Murraym]

You might want to use the Search box at top right to check out Intergrips and Cleco pins.

Cheers I’ll have a wee search. I have seen these used before, I was going to place a small piece of the sill behind the joint on the 1/4 and sill to strengthen the weld. Then put a plate behind the metal for the joint at the above the back window but if I am better to do a butt joint and use intergrips/cleco pins I’ll for sure do that!

 

[Murraym]

Is it a genuine panel? Lots of clamps so you can do a trial run to check all your lines and to get/keep the seam tight when you weld, can you borrow a spot welder? Nice to see an original non messed about Gsi outer 1/4 is a genuine gm panel

Yes sure is a genuine gm outer panel. The inside fuel filler repair was a aftermarket panel so took a bit of fettling

Don’t think I’ll be able to get a shot of a spot welder I’m afraid so going to have to work with what I’ve got!

Cheers it’s certainly lived a life but enjoyed doing it up so far

 

[Kayos]

Loved my gsi back in the day, painted it BMW Estoril blue

One on the regret selling list

 

[Blobber]

Genuine is good, doesn't matter so much with the stuff you can't see if the shapes about right!
33 years old it's going to have been around the block a few times
Love a good red top, one of the best engines back in the day and still are very capable