ok you gonna need all of that arch or isit just bubbles on the edge of your quarter?
- get angle grinder/airsaw and cut out the section that needs replacing. cut downwards starting from the middle of the panel towards the wheel arch as im sure they are double skinned there, make sure you dont cut through the second skin, just the first then use a hammer and boulster chissel to hammer it away from the second skin, if theres any spot welds there, drill them out and carry on until the sections out
- get your new panel and put it against the car, marking how much of it your gonna actually need, ide leave it a cm or so too big to start with then you can grind it down later.
- grind all around the outside of your new panel and your quarter, along the edge, to bare metal so it can be welded, put some sikaflex or any decent bonding adhesive along the inner arch
option 1 - now, if your a good welder, cut your new panel to the shape of how youve cut the quarter, so it meets it nicely and its flush, hold it in place with your mole grips or clamps.
option 2 - if you aint a good welder, leave the new panel about 2 mil too big and took it underneath your quarter, so it slots inside, then weld it, doin it this way will make sure you dont blow through with the welder.
- once its welded up, grind down your welds so theyre flush with the panel and prep a few inches either side of the weld with P40 or P80 grit on a sander or by hand, whichever your usin. put some easy sand filler on, rub down, re-add filler til your happy.
- before primering, make sure youve finished with nothing lower than P320 unless your using 2k primer (hardener usually 4:1 or 5:1 ratio 10% thinner) when P180 is fine.
its then ready to go to a bodyshop to be wet flatted n painted, nothings gonna go rusty.
This is how i do it, other people do it different ways, its just how theyre used to, there aint really any wrong way aslong as you get the corrosion protected, nicely finished end result.
