Question: I am working on a small project that has internal electronics components that are somewhat heat sensitive. I would love to do an over mold of soft silicone, but I am concerned about the heat damaging these components. Using a soft silicone, how much heat needs to be generated to do an over mold of lets say a one inch square cube?
Answer: It sounds like you are using a HTV (High Temperature Vulcanization) LSR (Liquid Silicone Rubber), if high temperatures are a concern to the performance of the electronic component, you could try running a RTV (Room Temperature Vulcanization) material instead. Although RTV materials (at room temperature) do take longer to cure than HTV materials (at processing temperature), an RTV material’s rate of curing can be similarly accelerated with the use of heat. Your best bet would be to determine the temperature at which the electronic component is damaged (or better still rated for), let’s suppose that’s 200°F, then create an operating temperature that is safely below the rated temperature, but still greater than room temperature, let’s say 150°F. The extra 80-90°F can make a huge difference in the processing time, turning a cycle time of a few hours, into a cycle time of a few minutes.