idvette wrote:
James I think you're underestimating the overall process of fitting a proper pad to a boat hull. The holy 2x6 would work, but only as a plug for a mould. The beauty of the 2x6 is definitely the pre-formed rounded corners and guaranteed straightness, but at the risk of expansion, contraction, and the rot factor. If you were to build a large trough, glue the 2x6 to the bottom of the hull, then set it in the trough (filled with reinforced concrete), you have a good base to work with. Then you could lay up a paper mache model for hydrodynamic testing (because every hull will react differently to a pad design) being sure to pay particular attention to the holes themselves (much like dimples on a golf ball, they will break up the surface tension and improve performance). There's a lot more science involved than you're letting on. Once the paper mache model is perfect, you can then fill the concrete mould with a smoothing agent (such as drywall repair compound, or if you're really up for it, bondo), re-fit your worked paper mache model in your concrete mould, and voilà, your almost end product. Ideally, you would map it out with a point to point computer and have it CNC cut from MDF, but without such technology one could also use a 2 part foam to fill the mould (foam never rots, see scream and fly for proof). After that sets, bond it to the hull with PL 3000 (or the previously mentioned leg bolts, if they were set in the foam during the curing process), seal and paint it. Only takes a few minutes to explain, but some serious labour involved. Good luck.
solid spruce WILL NEVER rot!!!