Silicone Addition Yellow 25 Set (medium hard)
This medium hard silicone can be used as a casting material. Suitable for fragile and detailed master models.
- Shore (A) 25 (medium hard)
- Quite liquid (self-deaerating)
- Relative / good resistance with respect to acid / aggressive substances
- Easy to mix
- After curing, very strong
- Low shrinkage (<0.1%)
Silicone Addition Yellow 25 is an (platinum) addition curing 2-component casting silicone that vulcanises at room temperature.
The silicone is quite fluid and characterized by a good tensile strength. The product is resistant to temperatures from -40°C to + 280°C and is suitable for fragile and detailed master models.
Note: Pot life / de-mould time is highly dependent on temperature! At a higher temperature, the processing time and de-mould time are shorter.
The Silicone Yellow 25 A and B component can easily be mixed by hand or by machine. Mix the A and B component carefully and in the indicated ratio (100 parts A and 100 parts B by weight). Process the mixture within the pot life and demould only after it is cured complete. Alternatively, you can speed up the curing process by placing the whole mould in an oven. Please note that air bubbles will then have less time to escape the casting. Even a small increase in temperature will shorten the curing time.
Trapping of air bubbles can be prevented best by placing the silicone under vacuum immediately after mixing. To prevent air bubbles, stir the A and B component well but slowly without stirring in air. We advise to use a figur of 8 motion.
Silicone oil may be added to reduce the Shore (hardness) of the rubber even further. Please note that the oil will not connect with the silicone network which means it may bleed out over time (years) and give a greasy surface and this of course causes shrinkage. If you want to thicken the silicone to make it paste like you can add Silicone Thixo A (NOT Silicone Thixo C !!).
Please note: This is an addition curing silicone. This type of silicones may experience cure inhibition when coming into contact with sulfer, nitrogen, amino groups and metl salts. If you are not certain that the products you use (including gloves, spatulas and cups) contain these ingredients, please do a little test first! These components are often found in many latex gloves, some platicines, glues, laquers, condensation curing silicones, silicone caulk, natural rubbers and 3D printing materials (mainly stereolithography).
When stored in closed container in a cool and frost-free location, the shelf life is at least 1 year.
If you frequently work with the silicone, it is recommended to wear gloves during processing and the room well ventilated. Safety instructions, please refer to the Material Safety Data Sheet.