Silicone paste Silast D-2 is a two-component composition. It is hardened (cured) at room temperature/room temperature vulcanizing (RTV).
The liquid silicone rubber “Silast D-2” is a viscous, self-spilling paste designed for pouring in order to isolate and seal different parts and details. Before use, mix with the hardener in an amount depending on the desired rate of curing.
Preparation of the mixture and its use
When the paste has stayed unused for a long time, it tends to become thixotropic or to form layers. After stirring, it goes back to its properties.
Before use and before mixing with the hardener, the paste should be mixed well with a mechanical stirrer. To the homogenized paste add hardener in a ratio of 5-6 parts by weight hardener to 100 parts by weight paste. The amount of the hardener is chosen depending on the desired cure speed, weight involved, ambient temperature, air humidity in the room and the skill of working with the material. Agitation of the paste with the hardener must ensure an even distribution of the two components and can be carried out for about 5-10 minutes. Before pouring the paste, it is desirable that it is left to rest for a few minutes in order to be deaerated. The mixture is then poured into a respective gap, opening, or other mold part. The paste has the ability to self-level. It is desirable to work with quantities not greater than 2-3 kg and the mixing to occur in a suitable container with a device able to pour a thin stream. If it is necessary, around the joint or other openings one can place some stoppers.
The gelling time (time during which work can be done without increased the viscosity of the mixture) with proportions of 5 parts by weight hardener to 100 parts by weight paste is about 1 hour at ambient temperature 18-20 ° C. ‘Silast D2’ hardens under these conditions for 3-4 hours, but the final curing and its maximal physical and mechanical properties are reached after 5-7 days.
Storage
The paste should be stored in tightly closed containers, which do not allow the penetration of the hardener. Under these conditions, shelf life is 1 year.
The hardener of the paste is also stored in a well sealed container airtight. Moisture from the air makes the hardener hydrolyzed. This leads to reduced performance, and hence to excess use of hardeners.
Safety and precautions
A detailed description is in the product data sheet.
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