Liquid CATALYST for Tin Cure Silicone rubber


We now have a new catalyst - blend at a 3-4%.

(CATALYST ONLY – You will need to have or purchase the silicone to go with it. All our silicones come with catalyst, this is for if you need extra)

It has fabulous smooth viscosity, will eliminate most air bubbles with a slight agitation, prolongs the pot life, and has a 2-24 hr set time. We recommend 3% however some people find the set time is quicker with more catalyst especially for brushing/layering on – Up to 10%

*Please note, due to the catalyst this product cannot be sent express post, please select the regular post option.


  • If you would like it coloured our  MICA comes in almost any colour which you can mix with your Catalyst before you blend with the silicone – it will blend easily and give beautiful colours


  • This catalyst is for our tin cure silicone and will work well with our O5 and New  tin cure 10 silicone Rubber

We use this silicone regularly in our mould making
It is brand new, fresh, perfect quality


  • No heat required - sets at room temperature 
  • Can withstand high temperatures once completed
  • Perfect precision - shows even tiny details
  • Can be used for making many different moulds/molds including: Soaps, Candles, Concrete / Cement, Art pieces, Plaster, Resin, etc.


  • Catalyst = Clear (can be coloured with our Micas)
  • Linear shrinkage 3% slow speed catalyst -
  • PLEASE NOTE: Increasing the catalyst used may increase the shrinkage. This will only be noticeable in very large moulds
  • Best working temperature: approximately 20 degrees, the hotter it is the quicker it will cure
  • Always test a small amount firstly
  • To avoid air bubbles, use less catalyst, the slower setting time will allow them to rise more easily



Print out a copy of the instructions for free here

Prepare your master (any medium except silicone)

Create a wall around the master, eg a cardboard wall or lego brick wall, attach the master to the base (so it won’t float in the silicone) you can use a hot glue gun. Make sure there’s no gaps.

Open the silicone rubber container and stir extremely well 
if you find that there are any lumps in the base of the container blend until the lumps become smooth again if you cannot smooth out all the lumps just throw those small pieces away before use.

Make sure you have this blended well before you add the catalyst as once you add the catalyst you only have a very short work time 

(To begin use only a small amount, say 100gms and begin at 4% catalyst.)

To colour, you can mix some mica with your catalyst (Make sure it is Renascent Bath & Body Mica as we not sure how others may react)

Mix the mica into the catalyst. Once it is stirred up and ready to use add the catalyst at 3-5% (the colour will assist you to see if the silicone and catalyst are mixed properly).

Add the catalyst and mix well so it is fully blended, if you get pockets not blended it won't set, if this happens, leave it for 3-7 days, it may blend through, but best to mix well. 

Have your master ready to go with the surrounds made and then pour the silicone rubber in a thin stream - over the top of your master, allowing the silicone to flow up from underneath, thus filling any crevices or marks and preventing air bubbles.

Fill to completely cover the master

Take a skewer or metal fork and gently stir, poking down the side to ensure any trapped air bubbles are released and pop up to the surface where you can pop them with your skewer. 

You have about a 5-10 minute work time before it goes sticky and 4-24 hours complete cure time - allow to set for 5 to 24 hours 

Once fully set, peel off your surrounds and pop your master out of your completed silicone mould

Give it a wash with warm soapy water, you now have a mould ready to use many times 

As we are professional mould makers and make hundreds of different moulds we are here to assist you if you have any questions or concerns.

It is fine for impression mats although don't pour silicone on silicone as they will firmly stick together. If over a plastic or lace cloth should be fine.

This information is copyright © Renascent Bath & Body / Lesley Mitchell
Individuals must test a small amount first to determine suitability for their purpose*Wear gloves and eye contact and do not allow the catalyst to come in contact with skin or eyes, if this occurs, flush immediately with water and if in contact with the eyes, seek medical attention.