I have just about finished making DIY interconnects using solid silver neotech wire. I was going to use cotton sleeving inside ptfe tubing but, I changed the design and, did not use the cotton sleeves. Each wire is inside an oversized ptfe tube and, two tubes for each IC, are lightly twisted.
I want to seal the open tube ends so I bought some Dow Corning RTV 748 sealant that is, a non-corrosive, 100% silicone rubber. It is also safe for food contact. The listed applications, on the package and the website, include sealing corrosive-sensitive electrical/electronic connections and wires.
The sealant will be in contact with the wire for less than 1/8". I plan to put a dab, on the tube ends, where the bare wires protrude so the tubes will be air-tight. Seems safe to me. I will appreciate any thoughts on this sealing plan.