Gloss Paint over Varnish / Danish oil

[BotchItYourself]

Can I apply gloss paint (oil-based) on top of:

a) Varnish (both water and solvent based) ?

b) Danish oil ?

without completely removing the original finishes ? What sort of preparation is required - just a light sanding or primers/undercoats etc… ?

 

[54aardvark]

Zinsser BIN springs to mind for the varnish, needs sufficient sanding for a decent key but it'll give you a good, solid primer base - used it on varnished surfaces and its brilliant.

Not sure if it'll do Danish oil though, try googling Zinsser and check their spec sheets, or do a small test patch, it will dry in 40 minutes then see how well it has stuck - give it a scrape with your fingernail, if it comes off easily its back to the drawing board.