I touched-up a couple of small rust patches on the sills of the Doblo this weekend. The two halves of the sill join just in front of the b-pillar. On both nearside and offside there was a scab of surface rust at the join.

It was easy enough to treat and paint. The kit supplied from Chipex seems to be a good match (GrigioUnderground). Apart from cosmetic appearance, I did not watch the rust to get any worse.

I have noticed quite a few local Doblos with the same rust scabs at the sill join. Is this a common problem?

Mines a 58 plate and has same problem.

Already treated some other bits, but a part of the sill just came to light

Every summer I try to prevent the rust from returning and tried just about everything. Only thing that worked was POR15, about £27 but worth it as this summer there is no rust showing back through again (and I live by the coast with the North Atlantic sea/wind)

Thankfully I haven't noticed any rust on sills (06) but will keep a watch out thanks to this post. I have had to hammerite the spare wheel and have the sump replaced (shame fiat can't paint the ancillaries as well as the body).

It's more unsightly than anything else, I am going to POR15 my other doblo's sill as a prevention this summer.
Previous owner had front mudflaps on and a few chips on the doors and rust was starting at these areas.