I noticed that the rear sill end on the drivers side is looking a bit bubbly, and upon inspection (ie. prodding it with a key) the paint (actually that black anti-rust covering that imports have below the door level) has bubbled in a few areas and there’s quite a lot of black watery gunk underneath. When the car is dry there are 3 small spots where the coating is cracked and water under the top layer is keeping these 3 small patches damp.
I scraped down to the metal and it’s all shiny silver under this black water, no rust visible anywhere, it appears to just be that the paint has trapped water behind it.
Any suggestions as to what to do to it? My first thought is to wire brush it back to bare metal then spray on some primer and overlay with plenty of black hammerite, but is there a better way to do it? The car is an old 92 Eunos and very tatty in general, so I’m not after a good looking finish just something tough that will prevent the sill from starting to rust for another few years.
It’s just the one sill end, the others still have the black anti-chip coating on and appear solid and blister-free.
It’s coming from the inside [:(]
It sounds like the sill drain holes may be blocked.
The drain holes are fine, and I don’t think it’s coming from inside - I had a scrape at it with a wire brush and there are little bubbles in the plastic paint where water has collected behind this chip-guard stuff, but pop these bubbles and remove the loose bit and there is clean silver metal behind and the paint appears to be stuck down fast right around the bubbles. I’ve wire-brushed off all of the flaky bits and there is a good solid sill behind now with a few of these round holes in the plastic where the bubbles were. Very odd.
Can’t find any evidence of holes in the metal or rust and a good thumping with the brush handle reveals no soft areas or anything other than solid metal all over.
Well, scratch that - I’ve just sanded it down and although the surface is fine I’ve managed to poke a centre-punch right through the metal (although I had to push really hard to do it). After poking around really hard it feels like there’s an area about 2inch by 4 inch that is slightly crunchy, although most of it stood up to a really hard push but I can feel it just starting to give when poked withthe sharp end of the centre punch.
So, what do I do now? The car is an old scruffy banger but it passed the MOT a couple of months ago with no problems. Are these areas of the sill structural? If not then I suppose I can filler over it and keep the car going until it rusts right out.
The other option is to get someone to repair this area - the other sill ends feel OK but the front left feels just the slightest bit squashy if I force the centre punch into it. How successful are repairs to these areas of the sills? If they’re not structural I suppose it should be OK.