plasterboard, screws and rust

[shadrack]

Recently I plasterboarded a fireplace and seeing as I didn't have the right length of drywall screws used the ordinary type (Screwfix "Quicksilver") and painted the heads with B&Q general purpose primer before plastering. I keep reading about the rust resistng properties of the black drywall screws. Is there any reason why ordinary screws would rust in this application? Do I need to worry?

Thanks in advance.

 

[pieman]

Not until the rust starts coming through!

Seriously, what's the worst that can happen? If it should, then a dab of decent oil based primer on the offending spot and repaint.

What else are you going to do - hack out the plaster around the screw heads, paint with a dob of oil based gloss, patch, fill, repaint? rip the lot out and start again?

If you've done it now, worry about it when and if it goes wrong; the screws are probably plated anyway...