Rather than hijack someone else’s similar thread I thought I’d best start my own. So my 1998 2.0 Ghia Ford Focus estate (140K) is in dire need of some sill work which I plan to do myself. Bought cheap off a mate circa 2011 when I lost my company car, he was always big on washing and polishing on a Sunday but never went near the underside with a hose. Anyway, the MOT runs out 21st of this month but I’m kindly being lent a Golf loaner for the duration. Hopefully then the pressure to get it done should be off a little and I can take my time, I am incidentally the original Mr Slow! So I’ve a few questions for the collective here please. Inside or outside – I’m lucky enough to have a double garage though as well as two Capris awaiting restoration it’s crammed full of general accumulated stuff. I reckon though if I get going and shift one of the Capris I can get the Focus in there. The BiL however, an agricultural mechanic (by apprenticeship) who’s used to working in the dirt, has said “You don’t want to be working inside…because of the fumes!”. As in grinding & welding. Surely if I just leave the front door(s) open? The bonus is he's on hand for advice but I think we fundamentally disagree on the "how". I'm thinking front wing off and replace the whole sill. He is I think more "just replace the area you need to". Experience – I’ve genuinely welded years back on all forms, MMA, gas, TIG & MIG. I’m going back to college 34 years ago and then very occasionally since then, mainly using a borrowed arc set or I think half a dozen times with the MIG to repair the odd gate or lawnmower bracket. I’m a dab hand (I think) with sheet metal . Equipment – I’ve a Clarke 130 MIG (recently used on the nephew’s car so all working) and the Aldi inverter arc. I’m wondering if for this I should buy a TIG kit to go on it? Spot weld drills – 6mm or 8mm? I prefer the solid, one piece spot drills. Only really used them in anger to de-spot the Capris when removing panels, like wings and the bubble on the scuttle. Assuming they’re all blunt I was going to get some more. I favour Dormer. On eBay I see some say Bergen make ones claiming “cobalt tip”. I thought these things were HsCo all the way through? The plan – The BiL seems dead against butt welding which I favour. He’s suggesting a lap joint (he has a joggler I can borrow) or “a plate behind”. I just think it’s building in rust traps. I was aiming to butt weld and get some Intergrips to assist. I fancy these “hard drive magnets”, heat then doesn’t affect them? I'm familiar with the "lay the new sill over the old and cut through both method". Looking at the pics below I'm assuming it's the usual "3 panel" arrangement of tuned down floor lip, inner sill then outer. I know I'm going to have some issues with the floor and inner sill lower edge. Wondering if best then to put the outer sill on first to have something to butt the floor and inner sill repair sections up to? Petrol tank – The pipe from filler to tank is corroded so I’m thinking to remove the tank is safest? There is the odd whiff of fuel after filling up. A while back I had some work done on both rear arches and the first 300mm or so going forward on the sills. (I wasn't in a position time wise or mentally to do it myself then). Just to scrape it through the MOT. It was new metal put in but tbh I should have taken out the God awful felt arch liners as they've undone a lot of the work. Really this needs doing again. Could be fun removing it as the repair sections were fully welded. Back in 2015 then: Some of the bits that came out: And now. I basically ripped off a whole length of underseal that was keeping everything together: You can see where the new bit stopped: Tbh I guess I won't know how bad it is until I start. The quicker I start the sooner I'll know! Any pointers appreciated!