We’re getting some new railings fitted on the garden wall as the old one have had it. We’ve had to cut the old uprights down flush to wall level as we’d probably have destroyed the wall trying to get the ends out. I now need to seal the railing ends up, so we can repaint the wall with masonry paint without getting fetching brown rust streaks all over the wall in a couple of weeks time. I’ll need to paint patches that will go over the end of the ~12mm iron rod and a bit of the surrounding painted cement to seal it all in before painting.

Any suggestions?

Normal rust stop paint or maybe some sort of sealant?

I’d cover the ends with epoxy to seal them and then paint that.

zin bin will get rid  of any stain