Hi all, hope everyone's keeping safe.

Was under the car today and noticed some surface rust under the strut towers. Dont seem serious but worth nipping in the bud now.

As this is such an awkward place and will get hammered from the elements what would the best technique be to treat it?

Nows the perfect time to do so as I'm not really using it.

I figured sand back and rust treat it then  zinc primer.

Not too sure if i should colour coat and leave at that or use under seal. Or both.

Its going to be with rattle cans so not too sure how best to get them up in there either.

Thanks for any advice.

This is what I would recommend:

1. Remove the struts to have much better access to the particular area. 
2. Sand or wire brush the area to remove any loose paint, rust and other contaminations.
3. Degrease the surface thoroughly.
4. Use a liquid rust convertor that stops the corrosion process and converts the rust into a black layer. Most commercial products are based on tannic acid that converts the iron oxide into ferric tannate and phosphoric acid that converts some iron oxide into ferric phosphate. Some products contain a mix of chemical additives that form a protective coating on top of the converted rust. When treated properly the rust process will be completely stopped.
5. Next you can apply any primer/paint you want. I recommend to use a good quality primer and body colored paint (like original). 

I would do as above and would first of all use This Rust converter then This Primer then it should be sorted to paint away. 

To be honest if mine I wouldn’t bother doing body colour, there is no point and I wouldn’t use aerosol. You can work it in better with a brush. You don’t need a decent looking finish up there. But I would do something with it to slow it down.

Thanks all. Half way through sorting it. Surprisingly easy to strip it all down, even the ball-joints came out easy. Used to working on much smaller cars.

Its amazing the difference arch liner make. Yea they collect crap in the sills so regular cleaning is needed but the rest of the arch is in great nick, just the bit in the center that was exposed.

Don't forget the 'after' photo!

Well today I'm going to be applying a colour coat over the top, just plain black, but here it is in primer.

Whilst its all stripped its getting new wishbones, droplinks, disks & pads, new brake fluid and going to give the calipers and drums a paint too. Wanted to give it new struts and mounts too but then the money ran out!

Or at least I'm hoping to do all that weather permitting. I used to work out in the rain but fed up of having to dry my tools out, plus i get achy now!
 

Wow! You HAVE been a busy boy in lockdown! 

Yup not using it so perfect time.

Doing to rear arches next. However did front suspension on my dads Focus, same age, and its spotless under there. And he lives by the coast....