Repairing a damaged plaster ceiling rose

[Pannacotta]

We have inherited a large and quite fancy ceiling rose in our victorian house.
A small section of it has broken off and I have found a retired plasterer who is happy to repair it.
But the product he has found to repair it with costs over £100, which seems a bit steep.
I told him I would look into alternatives and he has suggested we could use dental silicone to create a mould.

Has anyone done anything similar? Or just recommend an appropriate product we could use?

I have put out some email enquiries but nothing back as yet.

TIA

This material is perfect for a repair and is what a lot of ceiling roses would have been made of originally, cheap and very strong.
www.ebay.co.uk/itm/Plaster-of-Paris-Newly-Packed-Bag-of-Casting-Plaster-Choose-your-size-/370628889806?pt=UK_Crafts_Other_Crafts_EH&var=&hash=item564b340cce

This material is for making the mould itself.
www.ebay.co.uk/itm/5kg-General-Purpose-Resin-Hardener-Syringe-kit-FOR-FIBREGLASS-moulds-etc-/251004746630?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item3a710c7b86

Thanks for the links bureni.
Would I need to get both sets of materials?

Yes, you will need both though a smaller quantity of the resin will probably be all you need, try the ebay pages for a suitable quantity of the resin which will depend on the size of the mould you need.

Should have mentioned earlier that I have used childrens playdough and plasterine as a mould before , this is very good for fine detailed parts as it does not stick to the original plaster which you are using as a template, it is very cheap and easy to use.

Wow I wouldnt have thought of using playdough!
What would I use to fill the mould in combinbation with the playdough?

I use the dental rubber to make molds of small sections to replicate. It's easy to use, doesn't stick to the object you want to copy, picks up fine details and doesn't distort when you use hot compo/gesso/plaster and put (some) weight on it. You can wash and reuse the mold if the copy doesn't work. You can get it in small quantities from good art shops.

I would use plaster of Paris to make the missing section.

It may be cheaper to just replace the rose though - we got an exact replica of ours as the shop had taken a mould from down the street, and including fitting a huge rose was under £200.

not the rose is over 150 years old and set into a lathe and plaster ceiling which has lots of intricate detailing on it, so we couldnt take it out without wrecking all of this and the repair bill would run to hundreds.