Morris Minor Owners Club

looking at the product details on the dinitrol website, it suggests that the RC900 "rust converter" can be used as a bottom-coat for subsequent layers of primer: I wondered, does anyone have any experience of this?

I was thinking of cleaning the rust off where it's forming in my paint chips, and applying this to seal it up and make it "safe" so I needn't feel too hurried in doing the paint up properly. Reasonable?

I would suggest using the rust converter in very rust prone errors. It just stops the metal from oxidizing and turns the oxidized metal into an unreactive sort of black layer which you can paint over. Use this in prone areas or places that you cant clean to bare metal.
Otherwise I would say do it properly and cut through the paint to bare metal, zinc prime, feather the edges and respray . The converter will only get to what you see, not whats underneath the paint 5mm from where your cleaning for example!

YG

wiglaf, that is exactly what I have done to a Vauxhall Nova this week that I use as a run around. I managed to cut out the rot, weld in new patch or two, skim with filler and seal with the dinitrol until there is good enough weather to do final priming and paint.... oh dear wrong time of year for that then!

If it's the same as jenolite (ie basically phosphoric acid) then it will neutralise any rusty pits - and it etches the surface of any bare metal, and can be primed over once completely dry of course. But where possible - you should indeed rub away as much of the rust as you can, and then apply the acid.

Cool, thanks guys. I'll go ahead with the "quick fix" for the moment, knowing how long I've been getting around to doing the paint - and not knowing exactly when I'll next be able to borrow a friend's garage to finish it up properly, or have suitable weather to chance it...