Painting - Rusting screw heads

I recently built a small fence and used zinc plated philips head screws to secure the pickets. I am concerned that the screw heads will rust in time and would like to know if there is anything I can apply to them to prevent it. I had thought of spar varnish but am not sure that is the best choice. Any suggestions will be greatly appreciated.....buzcar

if it is an unpainted fence, a small amount of spar varnish, or rustoleum should help. if painted then i would just use a primer and paint the same as fence.

murphy was an optimist

You really should have used galvanized screws for your fence.Rust will always be an issue all you can really do is slow it down and spread apart the times of having to deal with it.

If the fence is painted dab an oil based primer for metal on the screws then paint over with your fence paint.

Note:"Rustoleum" is fine but this is a brand name for a very large product line.You'd want metal primer in their line.Since the screws are not now rusted you could use some of the primers for clean metal.

If the fence will be natural spar varnish may be the only thing you could try to slow the rusting.They will still rust and at some point will turn brown under the varnish.

About the only way to prevent rust from showing [other than replacing] is to counter sink them and then fill the hole with putty.