A second vote for wire ties.
I just redid the mast electrics on my boat and did the wire tie trick as well. Its a whole lot easier than trying to use foam. On my boat, the compression tube between the spreaders made life interesting whilst pulling.While I was at it, I also replaced the light fixtures. I used a Davis anchor light that claims to draw only .07 amps. Nice for those of us without inboards to charge our battery banks.Justin - O'day Owner's Web