Masthead Strain Relief

[CJV]

Hi folks,
I am replacing RF, 12V and wind instrument + wiring thru two 1/2 inch holes at the top of the masthead. The old wiring was siliconed into place but I don't believe that offered enough strain relief, based on the wear and tear on the RF cable.

I am thinking of black silicone grommets in the holes and tie-wraps on the cables above the grommets to hold the weight of the cables, perhaps covering the whole lot with white silicone for adhesion.

Any thoughts on this, or better ways some of you have done it?

(O yea, I'm a diehard engineer so I want to keep the masthead RF for the extra signal range. Call me crazy, but only when it starts to affect my upwind performance I'll switch to a stern pulpit-mounted antenna!)

Thanks in advance.
CJV