A Photo & Discussion Forum for Wharram Design Enthusiasts
looking for some Advice please!
I have just joined a friend on his fairly recently acquired Tiki 38 , floating around West Papua.
I am not a very experienced sailor but i am a carpenter,so excuse my lack of knowledge on terminology etc.i am currently doing repairs and maintenance
One main thing is , it appears that the hulls are slightly out of parralel and some of the spacers are either missing or very different in thickness and in material .
So my questions to the forum are ;
What is the best material to make the spacers or packers from ?
(I have considered : car tyre- hard wood - nylon board.)
Should they be Sika flexed or something to the hulls to prevent slippage ?
Can this be done with the boat in the water , or best on land ?
How to lift Cross beams from hulls to insert the packers ?
Lastly ! Any other advice on this procedure and the re-lashing of the beams to hull appreciated
I am only a week on the boatand I love the design , i can see this is the start of something ha ha !
The plans specify hardwood with graphite powder\epoxy mix between beams and "Packers". I considered nylon board but it may be hard to glue.
Before assuming that the hulls are not parallel, consider that each hull is organic since they are hand built. It is possible for the hulls to be parallel, but that the beam troughs did not line up exactly, which will put the beam askew inside the troughs. Therefor the spacers are individually made to fit as required.
It is a requirement for the hulls to be aligned, parallel, square, and level. It is not a requirement for the beams to be the same. Besides that, the locating/pivot pins in the beams will likely prevent you from making any significant changes to the orientation of the beams, as there is very little wiggle room.
Just a thought....When I got my T38 there were also gaps between the rubbers but it was because the lashings had come a little loose and the rigging lashings were tighter than the lashings. When I eased the rigging lanyards, really tightened up the beam lashing again, re-tenshioned the rigging lanyards, there were no gaps!
Ultimately you want the rubber on top of the hardwood blocks glued and screwed so none can work loose over time. Conveyer belting is good but really key it up with the grinder(sanding attachment) before epoxy and screwing. Sink any screws below the surface of the rubber to allow for compression. Keen to hear how you get on. Its one think to do a repair on the go but ideally these should be glued and screwed which can be done some time when you are able to remove the beams.
I built my beams to max size with stock size beamtroughs. The troughs were slightly out of line and I had to shave the 2 beam some to get it to fit when the hulls were aligned, and all of the spacers along the sides of the beams are of course different. The beam orientation in the troughs doesn't matter if the hulls are correctly aligned, and you will have to alter the spacers (and maybe the beams) to get the beams to fit when you first assemble the boat. I recommend that you build the beamtroughs twenty millimeters wider than plan to make fitting easier (Hanneke approved the change.) Once the spacers are installed, you will not be able to change them without disassembling the boat, changing the hull orientations, and then rebuilding the spacers to fit. There;s no reason ever to do that.
Tiki 38 hardwood beam pads (the pads under the beams) are very vulnerable to rotting out, particularly with a channel through the the middle of them, and I have replaced three of them over the course of eight years. These are the pads between the beams and the beamtroughs. My setup is a little different, with quarter inch nylon pads glued with 5200 and screwed (4 small screws set deep and buried in caulk) to the beams; these sit on the pads. I made the replacement pads out of glass layers set in graphite/thickened epoxy. These won't rot and they won't crush. I put the nylon pads on the beams because I was worried about the beampad edges crushing the beams locally, and I think its harder for water to wick up into the beam rather than down into the pad.
To work on the pads/beams without disassembling the boat put the boat on the hard and buy a jackscrew from Home Depot (70 dollars). Pad the beam near the inside of the hull where you need to work and raise the beam slowly with the jackscrew until the weight of the beam and center structure are on the screw and the lashings are loaded with just the hull weight. You can then loosen the lashings (one at a time) for that beam hull combo to work on the pads. The other lashings/beams will preserve the orientation of the hulls and beams but try to move it as little as possible while still getting enough room to work on it.
Boat trailer roller rubber has been used on my Pahi 42 as a packer
I agree about these hardwood blocks being being vulnerable to rot. I thought if I was building from scratch that I would make the blocks out of tufnol and then glue and screw conveyer belt rubber on top or Just use one block of red urethane rubber(thats what skateboard wheels are made of) and glue and scew these to the beam trough. I think with using hardwood, you need a really really good thickness of epoxy. I have just replaced two with tufnol and conveyer belt rubber, tough and no rot. I like your glass idea too. There are different epoxies that a better for "casting " blocks like these. A little more glass on the bottom of the beams around these points might make sense too.