Casting powder Raysin 250 4Kg Black

Raysin 250 Black is a casting compound consisting of natural calcium sulphate and black pigment. Due to its particularly high bending strength (250N/mm²), Raysin 250 Black is also suitable for large and very large castings.
Raysin 250 Black is air-curing, easy to work with and characterised by an optimum flowability.This casting powder is suited to casting moulds made of plastic (PET, LDPE etc.), latex, silicone and rubber.

Just like Raysin 100 and 200, Raysin 250 casting powder is suitable for casting all kinds of decorative objects, e.g. pendants/tags, candleholders, bowls, platters and much more besides. Can be easily demoulded after about 60 minutes (depending on the casting mould), completely dry after a few days, according to the size of the cast item. Also suitable for casting with children.

Raysin 250 Black is also great in combination with Raysin white 100 and 200!

Here's how to get started:
Processing temperature:
Cold powder or cold water extends the processing and curing time. This could impede the curing process, resulting possibly in a lower final strength. In order to avoid this, we recommend leaving the cold powder to stand overnight at ambient temperature (20°C). The optimum processing temperature for powder and water is between 18°C and 25°C.

Mixing procedure and casting:
The different hardness degrees (100, 200 & 250) have a direct effect on mixing ratios making them automatically different. The higher the degree of hardness, the less water needs to be added to the casting powder:
• Raysin 100:                     1 part of water to 2.5 parts of Raysin 100
• Raysin 200:                     1 part of water to 3.5 parts of Raysin 200
• Raysin 250:                     1 part of water to 4 parts of Raysin 250

Air bubbles may occur when stirring Raysin 100, 200 & 250. To minimise their formation, we recommend pouring the ready-to-cast Raysin slowly into the mould (e.g. over the concave side of the spoon) so that from the outset only a light layer free of air bubbles emerges on the surface. The rest of Raysin can then be quickly poured in. After pouring in, tap gently on the mould to dislodge any air bubbles.
Please allow the casting compound to dry thoroyghly in the mould and also allow the cast object to harden fully in open air after demoulding. If the demoulded items remain slightly wet, they can discolour.

Raysin 250 BLACK is not only a curing agent, but also a pigment with high colouring and covering power, and is extremely black to boot. All these properties ensure a distinctive black matt look which makes this casting powder unique and recognisable. The black pigment may leave residues on hands, clothes and the craft mat, which can be removed with a moist cloth and washing-up liquid. Wear gloves if required.

Due to its high pigmentation and the fact that it needs a small amount of water, Raysin 250 BLACK reacts slightly differently comparing to Raysin 100 and 200 when mixed with water. We recommend stirring the powder vigorously and thoroughly so that the black pigment dissolves optimally and is uniformly distributed. Slight frothing and streak formation due to the pigmentation can be expected, but this does not affect the final casting result.

Tips for a neat finish of Raysin 100, 200 & 250
• After drying, rub off any excess powder with a dry cloth.
• As with Raysin 100 and 200, the non-smooth rear side of the cast item with Raysin 250 is more porous and has edges with minimal burrs. This issue can be resolved by sanding the rough surface with fine sandpaper.
• Please take into account that sanding hardened Raysin items - regardless of colour - causes so-called sanding dust, which can be wiped using a moist cloth and washing-up liquid.

Tips for the casting moulds
Whether it’s about casting first with black and then with white Raysin, or vice versa, we recommend cleaning the casting mould thoroughly with lukewarm water and some washing-up liquid right after casting. If you use only one of the latter, a quick cleansing of the mould is just enough.