A resin model is often handmade in limited quantities by small companies known as garage kit modelers. More expensive than their mass-produced styrene counterparts, resin models are usually made with high quality in mind and feature uncommon subject matter. The model making process is an involved one, but once complete can result in a high quality reproduction of an original sculpture.
Take your model sculpture and place it in the clay halfway, to the point at which you intend to have the seam in your resin model. Smooth the clay's edge in order to provide a clean parting line. Using the corrugated plastic strip, surround the model completely with a plastic wall until it is 1/4 to 2/8 inch higher than your model, sealing the wall to prevent leaks.
Mix the silicone rubber thoroughly and then pour into the sealed mould box. Pour the rubber beginning at the corner of the box, allowing it to flow completely over your sculpture, and filling the mould box by 1/4 inch higher than the model. Allow the rubber to cure fully according to manufacturer's instructions.
Remove the clay from the model without removing the model from the rubber. Clean all the remaining clay from the rubber and the model. Using a hobby knife, cut two "U" channels into the rubber's edge on opposite sides for new rubber to flow into and provide a guide for reassembling the mould halves later. Place the mould half back into the mould box and then spray the half with mould release spray to keep the new rubber from binding.
Mix and pour silicone rubber into the mould box using the same procedure as the first pour. Allow the rubber to cure completely and then remove it from your mould box. Take the mould by the seam line, and separate the two halves of your mould.
Use your hobby knife to cut a pour hole into your mould and if necessary, any vents for allowing the resin to run to any hard to reach areas. Also cut small channels into the bottom of your moulded model for the resin to run into and push out any air in the bottom of the mould, taking care not to cut channels through to the mould's exterior. Remove the sculpture and you'll have a rubber mould ready for the resin pour.
Coat the two halves of your rubber mould with talcum powder to help remove air bubbles. Place a piece of stock foam board on both sides of the rubber moulds and use a pair of rubber bands to firmly secure the halves together.
Mix the resin compound thoroughly and pour into your rubber mould. Place onto a work surface and wait for the plastic to set. When set, open the mould and remove your new resin model.
After pouring your resin and placing it onto the work surface to set, pound on the surface a few times to jar the mould to help release any air bubbles.
When securing your moulds for pouring, don't seal too tightly, as doing so will distort your resin model.