|
Most marine ply is not rot proof. The key to marine ply is the glue used to bond the laminates. It is specifically formulated to retain its bond and structural integrity in adverse water and marine environments. The wood laminates will degrade over time with exposure to the elements if not properly sealed. Having said that, it is possible now to purchase treated marine ply that will resist rotting for an extended period. One would need to specifically ask for this.
It would seem to me that Matt's original suggestion of bolting four sections together would provide sufficient structural integrity. As to any vibration, it is difficult to bring any experience to the discussion. I have 1.5 metre round wooden fence posts set in concrete on our property that appear to be very resistant to vibration. Perhaps the success of wooden tripod legs is also an indication that Matt' pier proposal would be OK for visual observing.
Cheers
Steve
|