Inner and outer wheelarch repairs - to seal or not to seal?

[Matt Cotton]

Hi folks.

I have recently taken on a Sprint with a pretty rotten rear end - boot floor, arches, cills etc - I will get a thread going in due course.

Having picked up all the panels I need from Alun last week, today I made a start cutting out the grot and preparing repair sections etc..

Anyway, It will need rear arch repairs and inevitably some repairs to the inner too. I know originally the outer was spot welded to the inner, but wanted to get peoples thoughts on this. My concern is that if I spot weld it, both seams (inner and outer) will need to be free of paint for a good weld. I have tried weld through primers in the past and not been overly impressed with the resultant weld quality.
I want to protect this as much as possible, so would rather paint it with epoxy before the two arches meet - however again, this will compromise the weld.

Has anyone bonded the two together with Tiger Seal or equivalent? This would allow the two panels to be painted.

If I do spot weld it, it will of course get a thorough spray of Dynax/ Dinitrol till it pours out, so this may be as good as possible.

Any thoughts?
MC

[new to this]

when welding the inner and outer arches,I would use etch primer but only put a dust on
other wise the weld doesn't go through,once welded you can wax oil that area

Dave

[Carledo]

When I did the rear arches on the Carledo (2012/13, before the club repair sections were available) I made up my arch repairs, welded them to the cut back wings and then folded them up with a door skinner (for extra tyre clearance) against a generous cushion of Tiger seal, wiping away the excess that had squeezed out once done. 6+ years later the repair is still adhering to the inner arch strongly and the couple of miniscule scabs on one arch are more consistent with a problem in the welded arch repair to wing seam, than in the Tiger Sealed joint. I didn't put any additional rustproofing treatment round the inside of the arch joint.

The car has been in year round use in all weathers since this was done, it doesn't even get washed all that often! (So I'm a Philistine, sue me! I'd rather drive it than polish it!)

MY club GRP front wings and nose panel are also secured with Tiger Seal and self tapping bolts and it has worked well there too. It really IS ferociously sticky stuff!

Steve