A Photo & Discussion Forum for Wharram Design Enthusiasts
The total of time necessary to make the beam troughs + reinforcements in the hulls + lashing fixations and the beams by themselves is very important.
I don't understand the utility to have long lashing strakes along all the hull sides and so I fixed short lashing strakes only just below the beams with a glass cloth all around this pieces to avoid rot troubles in the future.
As I wish to have the minimum of maintenance on this boat, I thought it is more logic to allowed a vertical movement of the beams not in the beams (difficulties to make a perfect elongated holes with a good protection against rot and difficulty to check and repare the troubles) but in the bulkheads. For that, I drill a simple hole in the beams, in wich I glued a stainless tube to avoid to damage this hole in bad weather, especially with deep waves abeam. And the elongated holes are made in the bulkheads with flat stainless pieces on each side to protect the bulkhead wood.
As the lashings will be very tightened the vertical movement will be insignificant and the lateral movement so due too the little gap between the axes and the boat. From inside the hulls it will be possible to put grease in these slots.
Before to paint the beams I glued a thick 7mm rubber strip on the 3 bottom faces of each contact with the hulls, so in spite of the high lashings tension a slight movement will be possible and the transmission of the noise from one hull to the other will be attenuated. In fact the reason allowing each stem to move at a different time according the waves is due to the ability of the beams to twist and not due to the lashings.
To finish I made with with the fillet epoxy system little stops to position the lashing at the right place.