[TowerTalk] Bamboo Quad Spreaders

[WA3GIN]

Hi Folks,

Santa brought me a dozen 40ft bamboo stalks freshly cut and ready for drying and UV sealing treatment.  

I'm looking for suggestions regarding the sealing paint/varnish material used.  

In the past 920 years ago) I used marine spar varnish which was mixed for 100% outdoors use...much has changed in the paint/varnish industry since then.  I have no idea what works today.  

I tried polyurethane on one element and it flaked away in a few years of exposure to the sun.

I'm also open to speader color ideas. I know from experience that people who paint their front doors black experience severe wood spliting, apparently from the excessive heat build-up when the doors are exposed to sunshine, so I think black is not a good color but what about silver, white, sky blue?

Thoughts are welcome,
dave
wa3gin