I made some out of pressure treated 2x2 with coroplas decoys and they started slowly sinking after 3 to 4 hours. SO I am not sure if you need to use non-treated and paint/seal or what. That is my only experience. I got a pdf I wrote on how I made them, but I can't attach it.
"If you can't have fun doing it, it ain't worth doing, or you're just doing it wrong."
River hunting in my Wilderness Systems Kayaks; Commander 120 and Ride 135
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