Making a USB compatible casing for a teensy or Arduino micro

Trying to figure out how to make a casing for these small USB-enabled boards. One way would be to encase it in some clear resin, such as in epoxy or polyurethane or silicone. Another is to use heat shrink tubing. Here is what I have learned so far:

Heat shrink tubing works fine. The little fellow below is wrapped in three layers of it, first a red tube fitted from the back, then two strands of black tubing fitted from the sides, and finally black tubing fitted from the back again.

I've read that:

• Silicone may emit acids as it is curing. This may not be good for electronics
• Epoxies may change volume as it is curing and put permanent massive stress on components

I'll post more as I figure things out.