ACF-50 on Deep Stone Chips

[RyCliff]

Just bought a new to me daily which has a number of 5p sized paint chips, a couple of which are started to have a bit of surface rust.

In an attempt to stop them getting worse, I'm planning on sanding back the worst ones and then putting chip repair paint on. Does anyone have any thoughts on applying the ACF-50 I have for the caterham on the areas prior to applying primer?

[Dave Hardcastle]

I can't comment on ACF-50 specifically, but usually any paint manufacturer advises to clean surfaces of grease, oil, etc and take the surface to clean, bare metal for primer application. I would say it's a bad idea.

[Amos91]

You want something like Bilt Hamber Hydrate 80 if you want to convert the surface before paint. ACF-50 would be the final barrier once the paint is dry etc. 

[SM25T]

5p size chips ... wow 

[Nick Chan]

Hi Ryan, I reckon if you apply ACF-50 after the primer, the paint will fall off. As mentioned above, apply ACF after the paint is applied and dried

[Benton]

ACF-50 can act as a lubricant and effectively is non-drying. Not the thing to try to paint over I'm afraid.

[RyCliff]

Cheers everyone, I'll take a look for the Bilt Hamber product or something similar.

It's a former pool car from my dad's workplace. 110,000 motorway miles with not much attention paid to the paintwork. Hence the 5p sized holes in the paint. The good bits are plenty of towing capacity for trackdays, 60mpg and a purchase price that means I'm not fussed about adjacently parked SUVs!

[Nigel B]

Deleted, as I completely misread the question! 

[RetroRob]

Better not to apply anything over rust on a painted panel. Take the affected area back to clean metal while not damaging more paint than required. Make sure there is no rust creep under the local area.

Clean with panel wipe or a dab of paint thinners.

Then apply etch primer, then 30min to an hour later the touch up. A few thin layers to build it back to level.