How to make silicone molds by brushing way? 

Step 1 Handle the original mold

Choose a prefect original mold, Manually polish and smooth the model, clean the surface and dry it.

Choose the right parting mold-line, normally the mold can be made in two pieces and also can be multi-pieces for complex products, then it is better for us to draw the molded line on the model.(Notes: position the mold line on the top of the model when drawing, and run around the face and eyes of the animal model as much as possible.)

Step 2 Clay & mold-line

Put the fixed model on flat wooden board. Then cover one part of mold line with clay, and the other part is in the exposed. Coating a layer of mold release agent on the exposed part

Step 3 Weight part A & part B according to the mix ratio recommended

Weighting two parts in Electronic scale with mix ratio 100:2 or 100:5. 

Eg: Take 100g part A and 2g part B

Step 4 Stirring evenly

Remember to mix part A and part B evenly, otherwise the silicon rubber will be partly solidified and this will bring problems in your final operation. What’s more, the finished molds will meet a short life. All of these will cause a waste of silicone rubber.

Step 5  Vacuum pumping

For releasing the air bubbles, after mixing evenly, put the mixture into vacuum pumping for 3-5 minutes, without exception, this step takes less than 10 minutes. Otherwise, it will cause cross linking reaction, and no more further steps will be available. 

Step 6  First layer

Evenly brush the first layer of mixed silicon rubber on the model. Normally the first layer is brushed thinly to cover the model and the clay, so it should not be too thick

Step 7  Second layer 

Brush the second layer of silicon rubber till the first one is cured. Normally the second layer should be 3-5mm, Cover a gauze or cloth on it when the second cross linking reaction goes on, and use a brush pen or a brush to avoid any interstices. Evenly brush the third layer of mixed silicon rubber on the gauze or cloth 

This step will longer the mold using age, tear-strength, tension strength and duplication times. 

Step 8  Outer molding

Way 1: Make a square frame with four pieces of wooden boards, and make sure the wooden boards are fixed firmly, then pour the mixed liquid plaster into the frame. Shave the plaster-made outer mold with a scraper when the plaster is going to cured.

Way 2: brushing resin on the surface after silicone mold, Cover a gauze or cloth on it, then brushing the resin again. Repeat the operation for 2-3 times

2019-05-16