Quick rust / paint question

Hi all, just a quick one, hopefully with an obvious answer!



I sanded, Hammerite rust-killed and zinc primed a spot of rust on my R416, just after Christmas-Time. It's just been left as is since then. Basically, my question is: am I ok to paint over this now the weather is getting a bit more suitable to finish the job off?



I've heard people saying that primer isn't watertight, so it will have begun to rust underneath again, but I'm not sure I can see this being true! I've don't plenty of painting before, but normally only left the primer a day or two before finishing...



Thanks all, have a good Easter!

from the last news http://ift.tt/1rbESS7

via IFTTT