Looking for some advice. As my Jag is my daily, even with the snow flurries we are having in the UK at the moment, I have noticed the rust spots on my car have gotten worse over the last 10 months or so. I cant really afford a professional job to sort it for at least another 3-6 months. I have been debating sanding the rust away and doing an amateur spray job or use touch up paint. I know it will be a poor colour match and will nodoubt look ugly, but then the rust is fairly unsightly at the moment anyway, and Im thinking this might not be a bad idea to protect the metal underneath until I can afford to get it sorted by an expert.

 

Might start a different thread , The key is to stop it and may require after wire brush wheel on a drill some rust dissolver that comes in 2 different versions 1 addressing surface rust and the other intergrainular rust available at the auto part store .

 

I hate to be the bringer of bad news but from the pictures this is very, very unlikely to be surface rust. It is coming from the inside. If you start sanding and wire brushing you will likely end up will holes where the rust is now

Inside the sills and the wheel arch (double skin) will be much worse. A proper repair job will be quite expensive or a lot of work if you're handy with a MIG welder.


Before committing to repair this part you should carefully inspect the whole car. Specifically the inner sills where they meet the floor, the floor pan at the front and the bulkhead. These are all likely to be in a similar condition and you may find it uneconomic to repair.

It's the typical fate of so many UK X300's I'm afraid.


See this post from @Sogood as an example.

https://www.jaguarforums.com/forum/x...2/#post1840725

 

I second stopping the rust -- take the paint/primer way back and (what I have done in the past is) treat with phosphoric acid then come back on with an "etch" primer and finally use an epoxy primer on that.

Did this rust come up from below the paint, or were there nicks there ?

The epoxy primer I'm talking about is a 2-part mix but if you're just trying to hold over before a professional you can apply it with a brush and maybe top off with some rattle-can paint.

The epoxy is water-proof and should stop the moisture from the outside until you can get it done better.

 

That was my fear of attempting any temporary repair.

Its an odd situation really, there isn't any rust visible on that sill from the underneath (passenger side). There is a hole in the sill on the underside of the other sill, but no rust on the body. The inside of the sill looks clean though so perhaps someone has spayed something inside when the hole first opened?

 

You're in the UK so have easy access to Vactan on eBay. I've tried many and at least for me it's the best rust converter out there, all rust areas on my very rusty XJS painted with it are still fine and it sits outside for the past few years(also in UK). Check on eBay and get a small bottle. Use a wire brush and clean the rust area as much as possible. Very carefully check whether your sill is perforated and whether you can see any, even smallest, pinholes. If you cant, you're lucky, paint with Vactan, zinc primer and whatever else paint you can afford at this time. If there are any signs of pinholes etc then its going to be tricky. I think water here might be getting through the sill closing panel at the back. Wire brush it, especially where the sill closing panel meets the sill. When I did mine last year, the old seam sealer easily peeled off and opened up a few mm wide hole where water was blown from the wheel and was going into the sill.
If the sill is perforated, ideally it will need cutting out and proper fix but you can get around it with good results until this can be proper sorted. If that's the case, you will need access to it from the inside. Either get to it through the now discovered hole in the rear sill closing panel or if its not there, drill a hole in it so you can get to the metal on the other side and again heavily spray Vactan in there and then Dinitrol 3125 with an extension tube. Then do the same thing on the sill end and apply new seam sealer to it. Cover everything with something like Dinitrol 4941 and it should last a good while.
If you don't deal with this asap it will quickly turn into a terminal rust(if the other side sill rust didn't already). I had both sill rear ends done, one rear wheel arch, front floors and toeboards rust like yours with one front sill end done for approx ~£1000 in UK. A lot of work(I did half of the job) but most of it was the front end.