What finish work is needed after welding the new wells?
Documented on the Ford Mustang build
Published February 26, 2026
Grind and blend welds, apply body filler to smooth transitions if necessary, then seam seal all joints and prime with corrosion-resistant primer.
Full Answer
Grind and blend welds, apply body filler to smooth transitions if necessary, then seam seal all joints and prime with corrosion-resistant primer. Final paint or undercoating and reinstallation of liners completes the job.
Documented In This Build
Related Knowledge
What gauge of steel should I use for custom fender wells?How do you prevent warping when welding large panels?Do I need to remove the fender to make custom wheelwells?How do I prevent warping when welding thin sheet metal?What wheel/tire sizes can this modification accommodate?How much extra tire/wheel clearance can I expect?How difficult is this for someone with limited metalworking experience?How much wheel/tire clearance should I leave when shaping the fender well?
Related Parts
Seam sealer (tube)
$8
Body filler (Bondo or equivalent)
$12
MIG welding wire (ER70S-6 spool)
$25
Grinding/flap discs (pack)
$20
Sheet steel (18 ga / 1/16")
$40
Preformed inner fender / wheelwell panel (replacement or donor)
$120
Plastic fender liner / wheelwell liner
$60
Weld-through primer
$15
Pop rivets / fasteners (kit)
$10
Self-tapping screws / hardware
$10
Related Tools
Angle grinder with cutting and flap discs
MIG welder
Drill and drill bits
Hammer and dolly set
Spot weld cutter / chisel
Clamps and magnets (panel clamps)
Jigsaw / reciprocating saw (for rough cuts)
Body file / sanding block
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