Alginate Impression Moulding Powder 450g Bags

Alginate is a mould and impression making material, perfect for making models of various body parts or items.

Fast Sets in approximately 4- 6 minutes.

It works by combining the alginate powder with water to make a gel in which you put your object/body part in to make a mould, once the gel has set, you remove the object and pour Stonecast or Plaster (Sold on our other listings) into the mould to make a cast.

To Ensure Safe Use:
  • Don’t use product on broken or cracked/sensitive skin. 
  • Wash skin directly after mixing and moulding.
  • Avoid contact with eyes. If material enters eye, flush with water until clear. Seek medical advice if irritation persists. 
  • Do not ingest. If swallowed seek medical advice. Do not induce vomiting. 
  • Wear a suitable dust mask, goggles and gloves for prolonged or repeated / regular use. 
  • Store and dispose of the material in sealed packet or container in accordance with local regulations. Do not dispose of in sinks or drains. 
  • Designed to be mixed and applied by adults. This is not a toy. Store/keep out of reach of children. 
  • Pour and mix carefully to avoid generating dust. 

STEP-BY-STEP INSTRUCTIONS:

1) First get your equipment and space ready

2) Next, using a measuring jug, pour the required amount of water into the container that you are going to plunge the hand/foot into (or leave the water in the jug and mix in there, so its ready to pour quickly into the container or onto the body part after mixing).  Check the water temperature is 20-23 degrees.

3) Next measure the correct weight of alginate into another container using ratios given above

4) Empty the alginate powder on top of the water and start the timer.  Use the knife or flat spatula in figures of 8 motion to carefully bind the powder and water together.  If mix is lumpy after the binding stage, mix with a hand blender or whisk until creamy smooth. You have two minutes of mixing time.

5) Powder starts white, then after adding water, it goes bright pink.  2 mins from adding the powder to the water, its ready to mould.  So plunge the hand or foot etc in, making sure the hand or foot doesn’t touch the sides of the container.  (Or pour the alginate onto the body etc for other casting processes).  Wiggle the hand/foot a little to let air bubbles escape then hold still when the mix starts to turn pale pink as it has started to fully set. Keep still for a further minute until the alginate is fully white before wiggling the hand or foot out.   

Your alginate mould is complete and ready to cast:

6) Where possible, alginate impressions or moulds should be cast immediately. If you have to store them before casting, place in a moist atmosphere e.g. an enclosed polybag with a damp tissue and try to cast within 24 hrs. Don’t store it in water.

7) The next step is to pour casting plaster into the empty alginate mould and wiggle/jiggle the plaster in the mould to release air bubbles.  See casting plaster instructions for more details but remember NEVER PUT A BODY PART IN CASTING PLASTER as it sets hard and can cause burns. Only put body parts into alginate.

8) Finally, after the plaster is set in the mould, cut the alginate away from the plaster carefully using a craft knife. Work carefully to avoid breaking parts of the cast off. If you find you have holes in your plaster casting, this is due to trapped air bubbles and they can be filled using mixed plaster. Fingers can be stuck back on after drying with a suitable DIY glue

9) You need to allow your plaster model to dry for at least one week in a warm room before painting or sealing with acrylic paint/varnish.  If you paint too soon, the moisture will still be evaporating from the plaster and will spoil the paint surface.


Instructions For Casting Powder (Stonecast):

Add 1kg powder to 500ml water. Always add powder to water only. Mix thoroughly to a creamy paste. Using less water makes plaster harder, more water makes the plaster softer.


Tips and Tricks: 
  • For hand casts, either pose with closed fist or with all fingers open together
  • if moulding hands or feet, have suitable sized polythene bags or preferably used drinks or milk or margarine cartons (top cut off) ready.  Use the smallest bag or carton which will fit around object to minimise the quantity of powder needed. 
  • Have petroleum jelly available if long body hair is being moulded to during adult body casting and use it liberally.  Do not grease non hairy areas as the alginate slides off 

Chromatic alginate is so called because it changes colours according to the state it has reached, during mixing it turns pink and when it is set it turns white.

It can be used in two different ways either by immersing the body part or object in the gel or by spreading it. For a body part it best to immerse it into the gel, for face masks or other large surface areas it is best to spread it on.

Approximate quantities of alginate for indicated work: 
  1. 80-100g in a suitable small container (small food bag/yogurt pot/margarine tub) will do for a new baby hand or foot.  Use more for older baby/child.   
  2. A full bag of 450g will do for a medium size adult hand or breast.  Unenclosed areas of the body like a breast or bum also require Modroc Plaster Bandage to encase the alginate mould to make the alginate hold its shape.  You might want to check info on Google or YouTube for those more specialised castings.
  3. A large male hand will require about 675g of Alginate (1.5 packets of alginate)
  4. An adult foot will require about 900g. The bigger the foot (container) the more alginate will be required.  Remember feet vary hugely in size. 
  5. A full neck to crotch pregnant belly will require 4 to 5 bags but only attempt if you’ve practised smaller models as it is time critical and extremely demanding. 4 people are required to handle the process adequately and safely.  It also requires Modroc Plaster bandage to hold the shape
  6. A bum cast from mid back to upper thighs requires 4 bags of alginate plus 8 rolls of Modroc for encasing the mould (plus casting plaster about 10kg).