I asked Ann and Nev about the rudders on their Tiki 46.. They built them from Gaboon ply which is reasonably lightweight and I wondered whether they had originally reinforced the lashing points in any way and how the rudders had stood up to over 50,000 miles of cruising. Ann asked if I would post her reply on the Forum - here it is below.
"Our rudders are Gaboon ply made according to the Tiki 46 plans and fiberglassed. When we made the lashing holes, we were nearing the end of the build and had to hurry to get into the water in time to sail off before winter arrived in England. So we did not drill large holes and did not fill them with a mix of colloidal silica and did not drill smaller holes for the lacings to go through and we did not use a countersink to ease the entry to those holes. But that is what you should do! What we did, was to drill holes a bit larger than we wanted, we countersunk the edges to ease them, and then I coated the holes several times with epoxy using a gloved finger and some of the times the coating had a thickening agent it it. We were mixing a lot of glue about then and I did all the glue work, so I just went around and checked if the last coating was a bit leathery yet or not. If so, I added a bit. Gradually the holes became slick and that is all we had time to do. Never had a problem with it - so far so good. But you do it properly and be even more secure.
The lacing we used was dacron braid the size that the plans recommended (don't remember now but could look it up if you need) and we had to temporarily use some boot lacing through the first set of holes and also the last set of holes so we could put proper lacings into the middle sets of holes because the rudders are heavy and large and you gotta hold it in place some how when you do the first proper lacings. Then we removed the boot lacings and completed the job using good dacron braid. It is hard to make it tight but do your best and it will all unravel just a tiny bit when you tie the final knot that keeps the lacing in place. This all works out just fine because you need them to be just that little bit relaxed so the rudder will move easily. We did squirt some goo into the holes after doing the lacings and likely it helps a bit. It was 11 years ago and I do not remember which goo we used. Always we coat the lacings with antifouling and that seems to be an ok thing to do. Keeps the shells off and they are kinda sharp. We still have the original lacings in there and have done well more than 50,000 miles with them. They look new. I tap around those holes from time to time and never hear any rotty sounding thud. Always a good sound. But it is best to do as I say and not as we did!
Nev noted that Wharram plans said to use nylon against nylon rubbing plates at the bottom of the rudder and skeg where the rudder rests. He did not approve of that because that would wear out. So he used stainless on one surface and nylon on the other surface because that would not wear out. Again, this works well.
Some folks want trim tabs on their rudders and you can have them if you make the aft edge straight instead of with the bend. We do not have trim tabs so our rudders have the bend along the aft edge.
As far as we know, the beams are strong, hulls are strong, and all is well with what we built from plans. One leg of our wooden bimini has been replaced and we must soon replace the other end. The plan hatches are still fine and tight and easy to operate etc. All the store bought hatches leak and they are hard to operate. We intend to replace them with Wharram hatches but we are too busy sailing so far. The replacement intentions are now 11 years old!
If we had the Tiki 46 to do over, we would make larger windows at least on the galley side. Not much else would need to be changed though. All our doubts about the design were wrong. It works just fine.
As I write this, I think it might be useful for the Wharram Builders and Friends web site. Would you put it up for me?"
Ann and Nev