Tidying up rusty suspension components - Epoxy primer?

[PaulJC84]

I have an old 2000 A4 and the rear suspension wishbones and upright are looking pretty rough with surface rust. As is the subframe.

With some spare time over the winter I am thinking about tidying them up a little. I am not motivated enough to strip the rear of the car fully and get them powdercoated. I was thinking a simple freshen up by rubbing back the arms, using something to clean the dust away (suggestion?), epoxy primer and then some chassis paint.

I have used POR15 a long time ago but I remember if going a bit flakey and read similar when trying to do a bit of research.

Any cleaner, epoxy primer or paint suggestions would be really helpful please.

Here are some products i was considering:

https://www.frost.co.uk/pre-painting-prep-aerosol/
https://www.frost.co.uk/eastwood-optiflow-epoxy-pr...
https://www.halfords.com/motoring/paints-and-body-...

[E-bmw]

If you are just planning a light refurb/paint a wire brushing/emery clothing & then a coat of smooth hammerite is as good as you will need.

You certainly don't need to use aerosol "pre-paint".

[LargeRed]

just replace the rusty items, come the MOT the inspector will know. don;t waste your time, spend some money

[PaulJC84]

Thanks for the advice guys.

I think the arms are no longer available going by the price of used items now. They are far from failing an mot it was more just so things look a little nicer.

[LennyM1984]

ColourRestorer said:

I had always previously used Epoxy Mastic EM121 from Rustbuster for jobs such as this. https://www.rust.co.uk/product/cat/em-121-epoxy-ru...

The stuff goes rock hard and won't come off once it has set.
It is not cheap, but worth every penny IMHO.

However, eighteen months ago I found mention on the web of a company called Jotun who produce epoxy mastic for the marine industry. Indeed there was a suggestion, albeit unproven, that Jotun manufacture for Rustbuster.

Both companies refer to their thinners product as "No.17" which may be a coincidence. In fact I suspect that No.17 thinners is simply repackaged xylene.

The Jotun "Jotamastic Smartpack 099" works out significantly cheaper than the Rustbuster product, however you do have to buy it in larger quantities, which may not suit you.

You can find it here: https://www.smlmarinepaints.co.uk/primers/jotamast...

I too can second Epoxy Mastic. It's great stuff. I use it for chassis touch ups and once properly cured (not just dry) it is properly solid. It's also pretty forgiving in terms of surface prep - provided that the surface is clean, it'll stick. Trying to get it off is a little more tricky. You can gouge it off with a screwdriver or rub it off with 100 grit sandpaper but it's time consuming.

[Demelitia]

I’ve used the Bilt hamber epoxy on a subframe along with their Hydrate 80 rust converter. The two together seem to be a very good combo, along with being reasonably priced.