Painting fence - water based over oil based?

alex_163163

I painted most of our wooden garden fence a couple of weeks ago, but there was one bit I couldnt reach so I left it and asked my OH to finish it. I used a grey paint from the Cuprinol Shades range. 

When he’s come to do the section, he’s picked up the wrong can of paint (!!!!?!???!!!!!) and used the oil-based paint he used for the garage door instead. 

Now I’m assuming he won’t just be able to paint over the oil paint with the Cuprinol paint as one is oil and one is water-based.
any suggestions on how to prep the affected area, ready to paint with the correct Cuprinol paint? Sand down the affected area? Use a paint stripper chemical? Get a new OH who can read paint cans?!

dsm77

I'd just paint over a bit with the cuprinol and see what happens, it might be perfectly fine, worst case scenario is that it flakes off with lack of adhesion.
If it doesn't take then sand it off with 120 or 240 grit sandpaper and start again, paint strippers aren't really necessary unless you want something back to bare wood with lots of paint on.