Drysuit Heater Bulkhead Installation (gasket question)

[macado]

This is hopefully an easy question but I figured I would ask to be safe.

I'm installing a Light Monkey heater bulkhead in one of my drysuits. This is a dedicated bulkhead and does not go through the same opening as the drysuit inflator. Light Monkey | Equipment for Technical, Cave, and Wreck Diving

I've already used an appropriately sized hole punch to make a hole in the suit material and laid down a bead of RTV silicone (This was recommended by Light Monkey) on the outside of the suit to make a suitable gasket for sealing. I've screwed down the bulkhead on the suit and am waiting for it to cure. This is already done.

I searched a little bit and found similar threads where people have installed pee-valves using similar methods.

My question is do I need to make a gasket for both sides of the suit? The suit material is trilaminate (FLX to be exact). It looks to me like the sealing surface is on the outside of the valve but If I need to one for both sides I'll wait for this to cure and then add one on the other side.

Thoughts? On-side note..it's always a little nerve-wracking punching a hole in a perfectly dry drysuit..

 

[macado]

UPDATE: One application of RTV silicone on outside of the suit as a gasket worked perfect, at least for my leak and pressurization tests on land. I applied a small amount of RTV silicone around the hole that I made and then screwed down the bulkhead slightly, leaving a little room. I waited 24 hours and then tightened the bulkhead down all the way to seal better against the newly formed gasket.

If I do have any leaks then they're not coming from my bulkhead installation.