Has anyone tried to waterproof their hub motor?

Can I just take off the "lid" and put some silicone paste on it?

I think that would probably work. Mine came waterproof from the factory:

More pics here.

I got to ride a couple times that I got caught in the rain. I would think the Centripetal force would toss off the water. Plus the heat of the motor would help in getting rid of water also.

later
ray

If a motor is not waterproof, for example if it is vented, it probably needs those vents for cooling.

I read an interesting article on the troubleshooting page of ebikes.ca, its at:
https://ebikes.ca/troubleshooting.shtml

It seems to say, that total waterproofing is great, but if it breaks down, then you want the water
to be able to get out.
Check it out, there is a lot of good info there.

BionX are waterproof, i've rode on several torrential rains, for 2 hours 45 km and they go on and on....

I wouldn't worry so much about the motor. These are pretty well sealed coming from the manufacturer. My bike went through some serious torrential rain, hosing down and even buckets of water being splashed on it from above and it is fine. The only item on the bike that experienced any water damage was the throttle.

Both of my Crystalyte motors had Hall sensor problems due to moisture. I switched to sensorless controllers, aka "Pedal First" controllers, and they run fine even with the moisture inside. This is a common problem in the Seattle/Vancouver area.