Guide: making a coloured silicone hand

What are you going to make?

You make a flexible, coloured silicone copy of a hand. The alginate 3D gel captures every skin detail and the transparent silicone is easy to colour into a natural or bold shade.

Required materials

Product specifications

Preparation

We advise reading the entire guide before you start. Make sure the sleeve of the hand to be moulded is pushed up and that all materials are ready, because once the alginate is mixed there is no time to pause.

For this hand we use Silicone Addition Transparent 15 Fast. This transparent silicone is easy to colour and cures quickly, so the impression stays dimensionally stable before the alginate releases water.

Step-by-step guide

Prepare the silicone A component

Take the 1100 ml mixing cup and pour the full contents of the 500 gram silicone A component into it.

Add colourant

Add around 2.5 gram of silicone colourant (0.5 % of 500 gram) and mix to an evenly coloured blend.

💡 Start with little colourant and add in small steps. Too much pigment can affect curing.

Prepare the alginate

Fill the 1900 ml mixing cup with 1400 ml of cold tap water. Weigh out 470 gram of alginate, sprinkle it onto the water all at once and mix for around 30 seconds into an even mass. Do not over-mix and proceed immediately.

💡 Preferably use a kitchen mixer instead of a spatula. The mixer is easy to clean and alginate is non-toxic.

Submerge the hand

Submerge the hand in the alginate and move it briefly so air bubbles release. Hold the hand still in the desired position until the gel turns from pink to white. This takes about five minutes. Then carefully remove the hand.

⚠️ Do not wait too long afterwards; move straight to the next step or the mould will lose its shape.

Add the B component and mix

Quickly pour the full contents of the 50 gram silicone B component into the blend prepared in steps 1 and 2 and mix it quickly, thoroughly and vigorously.

Pour the silicone into the mould

The silicone is now ready to pour. Work quickly, because after around 3 minutes it is no longer ideal to pour. Pour in a thin stream so air bubbles can escape while falling.

Cure and demould

Let everything cure for around 30 minutes before demoulding. Then remove the alginate from the silicone and rinse the hand under warm water.

Post-cure and degas

We recommend post-baking the result at 100 °C for 2 to 3 hours after demoulding to fully degas the hand and reach final strength.

Final result

A flexible, coloured silicone copy of a hand, ready as decoration or a demonstration model.

Special instructions

• Wear an apron while working to protect your clothing.
• Alginate is single-use and can go in general waste after use.
• Too much colourant can slow curing; stay below 1 % of the A component.
• Post-curing improves final strength and removes any residual odour.
• The silicone is skin-safe once fully cured, but avoid prolonged skin contact during processing.

Storage

Uncured components

Store the A and B components closed, dry and at room temperature. Avoid moisture and direct sunlight. Well sealed, the components keep for a long time.

Cured mould

The cured silicone hand is durable and colourfast. Keep it at room temperature and avoid prolonged direct sunlight to prevent discolouration.

Frequently asked questions

Why does the alginate change from pink to white?

That is a built-in indicator. Once the alginate is fully white, it has cured enough to remove the hand.

Can I make a colour other than skin tone?

Yes. Because the base is transparent, you can use any silicone colourant to achieve the shade you want.

Why do I have to work so fast?

The fast addition silicone has a pot life of only around 3 minutes and the alginate loses shape within minutes as it releases water.

Is post-curing mandatory?

No, but it is strongly recommended. Post-curing at 100 °C degasses the silicone and improves final strength.