First Layer
How should bias plating be repaired? It is quite simple. So that after the repair it retains its original strength and rigidity… Well, it may not be much but that is the main and most important idea. This can be achieved, as always, in several ways. We follow three principles.
1. Use the same (or as close as possible) material.
2. When restoring, maintain the original number of layers and their direction
3. Ensure proper bonding of the material in and between each layer.
As for 1, I will only add that diagonals made of several (usually no more than 2-3) types of wood and even using plywood are encountered (e.g. A&R on which we laminated the transom)
As for 2, it is worth knowing that there were and are many ideas for diagonal plating. The first one from Draco43 (already appeared in the comments under the previous post courtesy of Marek) has 3 layers of mahogany staves of 8mm each sandwiched 90 degrees between each other (3x8mm90/90/90) Polonez has similarly. The Sharki (S&S from the Burmester shipyard) has, if my memory serves me correctly, 10×2.5mm mahogany veneers. Many modern biagos have outer layers in a bow-to-tail arrangement and a biagonal spacer inside. This results in a 45/90/90/45.
A Dar Szczecin, our more than half a century old vessel from the Szczecin Yacht Yard surprised us a bit with an 8m+3×2.5mm+8mm 90 layout, and we had to rebuild her this way.
The inner layer was damaged only in the area adjacent to the overhang arrow* After the proper beveling (1/12) Inserts overlapping the first veneer layer at the same time were glued in (West System). It is worth mentioning that the work of opening the sheathing took place in November, and then under the foil tent attached to the bottom there was a slow drying at a difference of 3-5 degrees C. The first gluing was performed in early February after the temperature of the plating was adequately raised.
CDN
*In units with diagonal plating there is often no clear boundary between the keel, the tail and the arrow of the overhang (conch) It is often one element glued from several layers from bow to stern.