Koster Restoration Plaster Key Course 25kg
Fast, coarse plaster key with polymer additives for the substrate preparation of Koster Restoration Plasters. Very good bonding also on very moist and highly salt burdened substrates.
For creating a plaster key as preparation for the application of Koster Restoration Plasters on mineral substrates (except gypsum). After a short time can be applied in one or more coats.
A plaster key is a thin slurry which is used as a bonding bridge between the substrate and the Restoration Plaster. Each 25 kg bag is mixed with 5.0 l to 6.0 l of clean potable water. Put 5 l of water in a clean mixing
vessel and add the powder in portions while continually mixing using a slow speed mechanical compulsory mixer (under 400 rpm). Add in portions as much of the remaining water as necessary to achieve the
desired consistency and mix until the mortar has a homogeneous texture. Mixing time is 3 minutes after all powder has been added to the liquid. The exact amount of mixing water can be higher or lower depending on the temperature, humidity, and absorbency of the substrate. The plaster key has the proper consistency when it can be easily cast onto the surface but does not run off. The slurry is cast onto the substrate with a brush or a trowel so that the plaster key is no thicker than 5 mm and covers approximately 50% of the area. After 30 to 60 minutes the Restoration Plaster can be applied.
|Maximum aggregate size||3 mm|
|Pot life||approx. 30 min.|
|Stiffening time||approx. 60 min.|
|Overcoat after||approx. 30 – 60 min.|
|Compressive strength (28 days)||> 10 N/mm²|
|Bending tensile strength (28 days)||> 5 N/mm²|
|Water required for mixing||5.0 – 6.0 l|
Consumption: 4 – 6 kg / m²