- a 300g batch is essentially 300g plus all the other components
- the foaming agent is essentially soap
- You need 20% foaming agent to latex (eg. 100g latex = 20g foaming agent)
- The curing agent contains sulfur which gives the foam it's memory and sponginess
- Need 10% of curing agent to latex (eg. 100g latex = 10g curing agent)
- The gelling agent makes the foam set (so it get's put in at the end). There is no set percentage - depends on the temperature, humidity of area. Usually around 10% but in England more like 14%. In winter use more gel
- Once the foam is set it can be put in the oven on a different day - process doesn't need to happen all at once.
- First step is putting in mold release as otherwise piece won't come out. Only need mold release with porous materials (plaster) not non-porous materials (fiberglass)
- Advisable to write down every thing about environment each time make roam latex (amounts, temperature etc.) to know how to keep improving.
- You can add pigments to latex mix to pre-colour it but latex is opaque so can't work in colour layers like you can with silicone
- Can use acylic paint as a pigment, food colouring etc. Avoid colouring with copper in. Oil paints will ruin foam.
- To paint on top of latex you need pax paint ( oil paint, pros-aide), greasepaint or airbrush.
- Foam is extremely light compared to silicone.
- You can reinforce foam for a suit with netting/fabric (lycra, tight material) because foam grabs onto material well. You can then glue these materials onto core then put the latex on top.
- Oven needs to be hot before beginning
- Need bleeding holes in the mold so air can escape when material is being injected and you don't get air bubbles or trapped moisture. It also gives a visual reference to know how filled the mold is.
- 85/90 degree ovem for the foam
To run a foam mix:
- Put lines/markers on the mold so you know which way to fit it together
- Need a mixer, a timer and a thermometer
- Add mold release inside and outside mold
- 200g latex = 40g foaming agent
- Add this straight into the mix
- 20g curing agent
- Add into mix
- Full spin for 2-3 mins till 2-3x original size
- Slower speed to refine it for 8 mins
- Add 28g of gelling agent and whisk for another 30 seconds
- Paint thin layer into negative to catch all the detail
- Pour rest of mixture in and press two halves together
- For injection fill syringe with mixture and push into mold, waiting until overflow comes out. Plug the overflow holes.
- Can also be painted into flat plate molds.
- Can take 10 mins to 1/2 hour to set.
- Put into oven.
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| Flat Mold Piece |
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| Closed mold piece |
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| Injection filled piece |
