Painting MDF with gloss

[ChristineM]

Hi - I've just started painting gloss paint direct onto a new white finished MDF windowsill (not a shiny finish - as if it's got matt emulsion on). Stopped because it's soaked straight into the end and front edge - the top surface looks fine. I've painted about 30cm and now I see that I should have put a primer on first. Will it be ok if I just leave it now and come back to prime it? What would you use to prime it with? Can I use 50:50 emulsion/water to save cash - or is it not worth it?

 

[Diyisfun]

You can buy mdf primer.
I would think you need to let what you have done dry thoroughly, then rub down & prime the bare edges.

 

[PrenticeBoyofDerry]

Am I missing something here? The white MDF window-boards are manufactured pre-primed, so don't need priming.