Encapsulating a key fob remote control

[e100]

Has anyone successfully encapsulated or weatherproofed a small button operated remote control device like this?



I sort of imagine making an envelope using PEVA plastic sheet and somehow welding the seams like on these food bags



Commercially I believe these are made use 27MHz RF welding equipment, however all I have is a hot air soldering station.
PEVA seems like a good choice as it's soft enough to allow the buttons to be easily pressed, but is also tougher than the plastic typically used for disposable food bags.

My previous attempt at waterproofing involved wrapping it with self fusing butyl electrical tape but the added thickness makes it difficult to locate the 4 button positions and the tape stretches too much to be used as an anchor point for a key ring or lanyard.

(This particular remote uses Zigbee in the 2.4GHz band)