Puttied windows

Hi. Hopefully using a water,based paint system you will not have this 'drying out' blistering again. I would use zinsser bullseye 123 to prime. Or/and if you can return the weathershield back to the big orange shed. Then get some zinsser allcoat exterior satin (water-based) it can be used in most applications without a primer and is re-coatable in an hour. For exterior applications its sublime

Putty is a oil based product to resit water comming in the window sides. To use water based product on putty it must be left to dry properly for at least 8 weeks. If that is not possible then the best thing is finish in oil base as the putty and the oil based paint complement each other. The oil base last longer. The water base only save time and to make it last as long as oil based product you should put on a extra coat. Both product is great once done properly. Plus water base is more tolerable if hou have animals or young children or adults around. Remember dont mixe the 2.

I'm not a fan of water-based paint, especially on the outside when painting putted windows, putty is made up of powdered calcium and boiled oil, please stick with oil base and be safe for a long lasting finish.

Never use any water based paint on the exterior, in my experience, you can never beat using a proper oil based paint, weathershied undercoat and gloss, has never let me down,