The wife’s Fiat 500 had an advisory on MOT for some corrosion on the rear axle.

 

I looked underneath and the paint is flaking so needs some protection. I found out this is pretty common for Fiats so i’d like to do some preventative maintenance.

 

I was looking around on the internet and found two products of interest, one is POR-15 and the other Bilt Hambee hydrate 80 (treats the rust) then UC from the same company

 

Has anyone used either on here? I did look at hammerite underbody seal but it sounds like it stays sticky forever which sounds grim to me

No one? 

Skodas used to be fully galvanized (sadly no longer the case), so not much corrosion protection needed on the body, perhaps that's why no one answers....

 

Other parts do need protection (exhaust, lower ends of shock absorbers, various bolts etc.). 

I always start with zinc or zinc-alu primer then either nothing at all, clear lacquer, or matching paint, depending on the area. Galvanic protection works best IMHO.

 

Following recommendations on here I have been using Owatrol Rustol and it really is superb, you can use an acidic rust convertor first but the Owatrol seals the surface completely and stops any further rusting as long as its not perforated.

 

I have been using it on 3 mobile site trailers which have spent their lives outside on fields & muddy building sites, the oldest is a 1975 one the ones done with a rust convertor & then grey stonechip paint are showing rust stains, nothing on the Owatrol ones even in the areas where it has not been overpainted, if you want to stop the rusting but keep the patina or just not be bothered with overpainting then Owatrol is the stuff to use!