Body rigidity

[12jslater]

I was wondering just how important a sevens rear inner arches are to the rigidity and strength of the car, on my ruby i have no metal left under the rear window where the arch meets the body however bellow that all is sound, I was wondering about the feasibility of cutting out the rot, taking it back to bare steel and temporarily making fiberglass repair sections, yes i know its bodge however i do use my old cars very regularly and I'm extraordinarily poor at welding, so its either a local snooty classic car garage taking the mick with prices and insisting on replacing the entire inner arch because of their "reputation" and refuse to just but weld in fresh steel (they're usual dealing with jaguar xk150s and the likes) or just repair myself with fiberglass for a few months while finding someone willing to do it reasonably (no MOT grade welding) look forward to your suggestions!

[Ivor Hawkins]

Can you take a photograph of the are in question Jake? Also where in the world are you? It may be that if it’s a simple patching job, one of us may be able to help out.

[Tiger]

I did have a similar problem welding some years ago.
Took some advice from ex- garage owner
Replaced some parts of my mig and soured higher quality gas.
With a little patience you can achieve a good finish.
Inner arches won’t be seen anyway .
Good luck
Tim

[12jslater]

I'm in tropical Wolverhampton, and unfortunately I cant get a photo I'm afraid as the camera on my phone is broken, its just where the inner wing meets the body beneath both rear side windows.

[Howard Wright]

Hi

I’d hate to see you slop fibreglass all over the areas that will eventually need a proper weld repair.  A possible alternative that would be just as strong as the fibreglass is to cut out the rot. Make up some steel sections that overlap the good metal. Drill holes in them at say 1” centres, clamp the repair plate in place and put a dab of weld in each one.

This was a common technique in the sixties and seventies, putting sills and A post panels on classic minis. You could even get away with a stick welder on its lowest setting and 1.6mm rods  . 

Once you’ve had a bit more practice with the welder you can Mig the panel in place properly without having to remove the panel.

Cheers

Howard

[12jslater]

when i say I'm bad at welding, i just blow holes through 1mm steel, cant even put a dab of weld down, i just burn straight through it, hence my issue, I've sat down and tried for hours to get it right and i can never get past that stage, i try turning the welder down by little increments and i just end up getting it so low it wont even weld.

[Howard Wright]

Oh Dear.

Are you using an arc welder or a Mig?  Arc welders are pretty vicious on thin steel but Migs should be much more controllable.

I’d spend some time practicing.  But if all else fails pop rivet the repair panel on. At least it will be easy to take off when the weld repair is done.

Oh and by the way only use weldable primer on any repair you do. No underseal or other goo.  You don’t want to be cleaning that off the steel before the final welding  .

Cheers

Howard

[Martin Prior]

I would definitely NOT cut out any metal, however rotten, without immediately welding in a new piece. Personally, I much prefer to patch and plate, rather than replace entire sections.

[12jslater]

the metal in question is already thin/ not there, cutting would just be to make the hole rectangular so it could easily be repaired, and the melder in question is indeed a mig welder, see told you im bad, give me a vintage watch, i rebuild and service, give me a vintage radio, the same, but with welding i am 100% useless haha, really isnt for me

[andrew34ruby]

Fibreglass matt and resin are damned expensive these days. Could you find a small back-street garage that would weld it for you? Or maybe someone mobile? Or could you do a permanent job with small nuts and bolts?

I learned to weld with oxy-acetylene when I was 19, it was easy and i was good at it after a few weeks. Mig is more tricky and I'm still improving after 36 years of miging.