Painting putty - overlap to glass?

[jon92]

I have always overlapped paint onto the window glass slightly when painting putty. However, I recently heard that only the gloss coat should go onto the glass and not the primer nor the undercoat as they don't adhere. Anyone know if that is true? It's normal linseed oil putty and Dulux oil based trade paint.
Thanks.

 

[ic1927]

We've always overlapped the putty with both undercoat and gloss, it gives a neater finish and provides a seal against water getting behind the putty. I've never known this method not to stick to the glass, maybe acrylic primer/undercoat might not stick, but oil/solvent based undercoat and gloss should.

 

[Robbie uk]

Both undercoat and gloss should go onto the window by a 16th of an inch. The gloss needs the undercoat to adhere and to seal the fine gap between the putty and the glass.

 

[jon92]

Thanks for your replies, sounds like it was just a nasty rumour. Which is a relief as I'm about half through painting the house already.