Rust On Front Subframe Mount - How To Fix?

[AndrewP 1 1 Cars]

As my car has been off the road for the winter, I decided it was time to get it ready for the summer (and it's MOT) and change the discs and pads. However, a quick job has turned in to a long one as the disc retaining screws have all sheared. Anyway, I digress! More worrying, I noticed the paint was starting to flake around the front subframe mount on the passenger side, so I've chipped off the loose stuff and this is what it looks like:

 

 

Obviously, it's pretty manky and needs cleaning up plus I'll need to drop the subframe (and I'll strip it and get it repowdercoated at the same time) but how is it best to repair the mount? I'm pretty handy with the spanners and confident to tackle most oily jobs, but I'm a complete noob when it comes to stuff like this! The metal is all solid and it looks like just surface rust, so I'm guessing a wire attachment on a drill would be needed to get it back to bare metal first? But what products should I use on it to get it looking like new?

 

Many thanks in advance

 

 

[Kane 34]

Attack it with the wire wheel of death, something similar to this >>

 

http://www.screwfix.com/p/titan-twist-bevel-100mm-brush/64592?kpid=64592&cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&cm_mmc=Google-_-Shopping%20-%20Tools-_-Shopping%20-%20Tools&gclid=CjwKEAjw0KK4BRDCiKHD5Ny8pHESJACLE6205eGGPSUJZTA-v9fiqS1HeojNW0iaP5PD5ge_I_8LlhoCI5Xw_wcB

 

If there is heavy pitting which won't budge with the wire wheel the best products I've used in the past is from bilthamber. Deox-c gel would be best on that location

[AndrewP 1 1 Cars]

Thanks. Once all the surface rust is off and it's back to bare metal though, what's the best thing to do with it? I've been doing loads of reading and I'm leaning towards white Epoxy Mastic 121.

 

Any thoughts on this, good or bad?

[Kane 34]

No experience with that specific product but for underside areas I've used Jotun Jotamastic epoxymastic previously. Designed for boat hulls so extremely good for corrosion protection, even on salt covered roads up here in Scotland.

[Tom Fenton 1,541]

You need to use a phosphate rust converter really, even if it's wire brushed clean there will still be traces of iron oxide (rust) in pitted areas. Then overpaint with something decent as per above.

[Kane 34]

The Deox-c if used correctly should clear up all rust within the area although a coat of something like bilthamber hydrate 80, a phosphate rust converter as Tom suggested, would be the belts and braces approach.

 

Worth the effort I'd say for what is probably a tenners worth of product and an extra 15 minutes work.

 

Edit: Jenolite is another phosphate type product that comes highly rated. Used it a couple of times and seems to be holding out reasonably well.

Edited April 9, 2016 by Kane

[AndrewP 1 1 Cars]

Thanks gents, much appreciated and all makes perfect sense. The amount of products to choose from is bewildering so it's difficult to know what's best! I'll post some pics up when it's done.

[Alan77 78 1 Cars]

Bilt Hamber Hydrate 80 is good, but I've found FE-123 to be much better.