Repairing Victorian masonry windowsills

I have just bought a 100 year old house that has masony window sills on the outside. Some of them are cracked & some have parts that have fallen off exposing a steel rod inside.

What's the best way to repair these? I'm thinking of rust treating any exposed metal & then making a wooden mould into which I put a suitable concrete mix. That's OK as long as the mould is accurate to the original.

Any other ideas gratefully received.

Thanks Blacky

about 15years ago i had a job to repair blown concrete beams on tower blocks. These repairs were not structural but cosmetic. We used a product which at the time was called a "modified mortar". The product came in a two pack system, one part being a grey powder and the other a resin. I'm sorry i don't have any more information, like i've said it was a while ago

Are they stone or cement. Victorians were not using reinforced concrete. They might have been repaired before??? There are a couple of guys in Manchester called Brick-Aid who fixed stone cills recently. Not sure of contact details.

Blacky - you want fast cure epoxy repair mortar, something like Concrex Rapid Set or similar (there's lots on the market). The sills have cracked 'cos the iron rods have rusted, then expanded, causing the cracking. Don't bother fixing the iron - not longer needed - hack/cut them out, then repair with the above type of mortar. Tip - drill into broken faces, hammer in some plated or stainless screws to act as keys.