What will you make?

You first make an impression mould of a real hand using alginate, a fast curing and skin friendly impression material. Then you cast into that mould a soft, very flexible silicone that you have brought to skin tone beforehand with flocking. The result is an ultra realistic copy of the hand, including skin lines, veins and nails.

The combination of flocking fibres in the A and the B component gives the silicone a natural colour depth that cannot be achieved with pigment alone. The technique works for hands, feet and other body parts.

Required materials

Product specifications: Silicone Soft Flex 00-35

Preparation

Read the whole guide before you start. Make sure the sleeve of the hand to be moulded is rolled up and that all materials are ready. Put on an apron to protect your clothing. Work in a space where you can spill.

Timing is important in this project. Soft Flex 00-35 has a short pot life of 6 to 8 minutes, and the alginate cures within a few minutes. Therefore prepare the coloured silicone first and only mould the hand afterwards, so that you can cast immediately after.

Step by step guide

Weigh and colour the silicone A component

Pour 350 grams of Soft Flex A component into a mixing cup. Add a small base amount of flocking as a starting colour and mix to an even mixture. The flocking fibres give the silicone a natural colour depth.

Build the skin tone with flocking

Build the desired skin tone with flocking. For a standard skin tone you combine red flocking with a small amount of blue flocking. For a redder skin you add more red flocking. Add small amounts each time and mix regularly until the right colour is achieved.

💡 Tip: For a dark skin you combine brown flocking with black and blue. Work in small steps, you can always add colour but not remove it.

Colour the B component identically

Repeat the colouring with the B component. Weigh 350 grams of B component in a new cup and add exactly the same amounts of flocking as with the A component. Mix well. If done correctly, the B component has exactly the same colour as the A component.

Mould the hand with alginate

Fill a container of about 1900 ml with 1200 ml of cold tap water. Sprinkle 400 grams of alginate powder onto the water and start mixing immediately. Mix for about 30 seconds to an even mass. Do not mix too long and proceed directly to the next step.

💡 Tip: For mixing alginate preferably use a mixer and not a spatula. The mixer is easy to clean again and alginate is not toxic.

Immerse the hand in the alginate

Immerse the hand in the gel as soon as the alginate is mixed. Move the hand briefly so that air bubbles loosen and float to the top. Then hold the hand still in the correct position until the alginate changes colour. After about 2 to 3 minutes it has cured and you can carefully pull the hand out.

⚠️ Do not wait too long: After curing the alginate slowly begins to expel water, which reduces the quality of the silicone result. Therefore cast the silicone into the mould shortly after demoulding.

Prepare the mould for casting

Hold the mould upside down briefly so that expelled water can run out. Set the mould upright again and dry the alginate briefly and carefully with a hair dryer. Do not make the alginate too warm or too dry, because then detail can be lost.

Mix and cast the silicone

Pour the coloured A and B component together and mix well. Scrape along the edges of the cups so that the full contents are used. Then cast the silicone into the mould in a thin stream. Fill the mould two thirds and hold it at an angle so that air can flow out of the fingertips. Then fill further up to the top.

💡 Tip: Due to the short pot life of 6 to 8 minutes you have to work swiftly. Mix and cast without interruption.

Demould and finish

Wait about an hour and then remove the alginate from the silicone. Rinse the hand with warm water, this is good for the curing process. The hand may still be slightly glossy. Work the gloss away by dusting the hand with talcum powder for a natural matte skin.

End result: an ultra realistic copy of a hand, with a natural skin tone and detail down to the skin lines and nails.

Special notes

• Work swiftly, because both the alginate and the silicone have a short working time.
• Always add flocking in small steps and mix regularly, you can no longer remove colour.
• Keep the A and the B component exactly equal in colour, otherwise the end product discolours unevenly.
• Cast the silicone shortly after demoulding the alginate mould, before the alginate expels too much water.
• Dry the alginate only briefly, too much heat damages the detail.

Storage

Uncured components

Store the A component and the B component well sealed between 10 and 25 degrees Celsius, away from direct sunlight. Store alginate powder dry and airtight, moisture makes the powder clump. Close packaging immediately after use.

Cured end product

Store the silicone hand in a dry space at room temperature, away from direct sunlight. Lightly dust the hand with talcum powder to prevent sticking and to preserve the natural appearance.

Frequently asked questions

Why do I use flocking and not ordinary colourant?

Flocking fibres give the silicone a natural colour depth that cannot be achieved with pigment alone. The fine fibres mimic the subsurface colour nuances, which makes the end result look much more realistic.

Is the alginate safe for the skin?

Yes. Alginate is a skin friendly impression material that is not toxic and can be safely applied to the skin. It is also used for body casting of baby hands and pregnant bellies.

Why do I have to work so quickly?

Soft Flex 00-35 has a pot life of only 6 to 8 minutes and the alginate cures within a few minutes and then expels water. Therefore prepare the coloured silicone before you mould the hand, so that you can cast immediately.

How do I keep the skin tone equal in both components?

Weigh the flocking accurately and add exactly the same amounts to the A and the B component. Mix both until they have visually the same colour. An uneven colour distribution leads to patches in the end product.