A while back, I added the factory motor mount to the transom of my Capri 14.2 sailboat. I noticed that the factory rudder gudgeon support had a plastic like material shim between the support and the transom. I've noticed on other modifications on this forum that in some cases, shims or spacers made of teak or other types of wood were needed for this purpose. To either compensate for an uneven surface or added reinforcement. Such as boarding ladder or engine mount systems. Also as a spacer between the two layers of the transom. I went to both Home Depot and Lowes searching for this type of material and could not come up with what I was looking for. My wife suggested that I should check out kitchen cutting boards. Sure enough, this was exactly what I needed. I found most were 1/4 thick with a smooth surface, and made out of polypropylene. It's easy to work with and cuts very nicely on a table saw and you can drill nice clean holes with a sharp drill bit. Easy to shape with light sanding. Depending on the size of the board, the price at Wal Mart was less than 10.00 bucks. This stuff is hard as a rock and does not require in maintenance. I hate to admit it, but sometimes the wives do come up with better solutions for us nautical experts.