Etch primer trouble

Captain Slow IRL

I'm doing a bit of touching up and have started on a lower section of a door where a rust patch has developed from a scrape.

I had a very small spot taken back to bare metal and put some etch primer on it. But the etch primer has reacted badly with one of the previous coats on the door and it bubbling badly in some spots.

I don't want to go taking the whole lot back to bare metal, it is a very small spot and I was going to get away with spraying only the lower half of the door; what would be the best way to deal with this?

dgt

If it's reacted you may do a bare metal respray or it'll never be right. How bad is the rust?

Captain Slow IRL

Not bad; just surface, small and localised.

Chimaera

Perhaps mask off around the area you want to treat? It'll mean sanding back later to feather in the edges but you won't have ruined the rest of your paintwork.

Captain Slow IRL

It was a bit of filler that was causing the reaction!

I took it out and got the primer onto the bare metal, I'll refill and respray over the weekend.