Got a couple of rusty bits on car --on cill and tailgate. Metal behind looks ok--is it just a case of sanding it down and painting a rust inhibitor on it and couple coats of car spray paint to nearest colour. Not too bothered about finish --just slow the rust down. Don't know what products are on the market these days.

Almost all rust (esp on cills / tailgate and other double skin areas) comes from the INSIDE. Treating the outer surface will make it look ok for a while - but it will be back.

That said there is bugger all else you can really do other that be a bit vigorous digging into the rust holes ---- if they enlarge well beyond expectations (especially on the cill) life can be tedious/ tricky and the writing is on the wall so to speak.

If you DO end up with a fair sized hole in the cill (say 5p size) then screw up a piece of aluminium gauze with a bit of strong thread tied to it, push the gauze through the hole and pull the thresd so the gauze is tight against the back of the hole. Now you can apply filler over the gauze. Rub down, paint etc. If you are lucky that will not be spotted on a MOT. Anything more than 5p size = go for a replacement cill.

Been there. Done this. We all have probably

Snod

cheers Snod. I think the one on the tailgate looks like water from inside. The ones on the cill (or bit just below the door) looks like where the paint has chipped with people kicking it when getting into car.
Must be 30 years ago since I last messed around with gauze, fibreglass and fillers. heres hoping.

When you run a 30 year old VW camper as I did (hence the avatar) then you learn a LOT about repair procedures/ bodges. Eventually I even had to learn to weld - not very well but it always passed the MOT.

Snod