Water collecting in the mast support area

Stored outside year-round, usually under a tarp, my TI seems to collect water in the mast support area in spite of my best efforts (heavy rain, snow) and I'm worried about ice expansion. Would putting antifreeze in the mast hole for storage over the winter cause any problems with the hull material? Any better solutions?

Thanks.

Store your ti upside-down
(No places where water or durt can collect)
Peter

What kind of tarps are you using? I suggest any poly tarps like these https://www.tarpsnow.com/poly-tarps.html for protection from snow and rain specifically.