Can I do this and be safe?

[Rivethead]

I have a couple of cables coming through my firewall and as it turns out the location would be perfect for a wire run that's needed. The wires are the thermocouple connects for my LASAR ignition. I'm thinking of two layers of heat shrink on the wire along where the cable and wire contact each other. Then finish it off as needed with RTV and a second clamp.

 

[rocketbob]

I don't think you'll have any problems with this but the cables shake, and don't flex like wires do so down the road you might have some chafing.