A Photo & Discussion Forum for Wharram Design Enthusiasts
Hi - have been rebuilding my tiki 26 grp beams and now looking at how grp cockpit should locate. It appears in my case the cockpit location method may have worn the beams and accelerated failure.
Any good ideas? Is it possible to have a system where the cockpit is lowered rather than sandwiched between beams?
A simple fix would be to apply rubber strips to the areas of the cockpit and beams that rub/touch each other.
I've also got a GRP Tiki 26 which I've reconditioned. I didn't find any sign of wear between the cockpit and the beams. When it's all assembled there's no noticeable movement between the two. Maybe on yours there has been in the past. When mine goes together it's all quite tight but I can see if the beams were a fraction further apart maybe there could be movement.
Does yours have four thick hardwood blocks supporting the rolled top edge of the cockpit? On mine they're about two inches thick and I think they carry the weight, rather than the cockpit resting on the bottom lip of the beams. I can see if that lip was carrying the weight it could cause problems. I've attached a photo of one of the blocks on mine.
Hi Robert - super helpful and Paul thank you
My pod is same style with roll top edges - - any top tips on assembly apart from getting some strong teenagers to offer it up - I presume yours gets sandwiched between beams?
- what do you do for seating? I have two plywood boards that sit on top of roll top and a wooden strip that attaches cabin - very unsatisfactory!
Have just done some measuring...the distance between front and rear of cabin where cross beams lash is 8' ie 96" and length of pod is 98" ie there is only 1" of overhang at each end...makes sense to have a deeper former for pod to sit on as in roberts 2" blocks
I believe these blocks are essential. The lips around the inner face of the beams are a weak point and I wouldn't want the weight of the cockpit chaffing away at them.
Regarding assembly, it is (just) possible to do it single handed if the cockpit is sitting on the ground under the boat, but it's far easier with two people. My method is roughly as follows:-
1. Position the hulls the right distance apart by fitting the front aluminium beam and rear netting beam.
2. Fit and properly lash the mast beam in place. This one takes by far the greatest loads and it's important to fit it right, snugged down on all four bearing pads. You'll probably have to jiggle the hulls around a bit as you go, to get the beams sitting right.
3. Sit the aft main beam on the decks, leaving enough space to lift the cockpit through.
4. Lay a couple of 4x2's across the cabin tops and use ropes over them to gradually lift the cockpit up until it's at the right height. It's easy to lift one end about a foot at a time, then use the rope to hold it while you lift the other end. Slow and under control.
5. Once the cockpit is at the right height, slide it into place on the blocks on the mast beam. Loosely lash it for safety.
6. Move the aft main beam into place and lash it. If it's not possible due to the space for the cockpit being too tight you might have to ease off the mast beam lashings and move it a fraction, but make sure it's properly tightened before tightening up the aft main beam lashings.
7. Tighten the cockpit lashings (the blue ones in my pic).
If you've got plenty of strong helpers you can do it without the 4x2's and ropes, as people can stand where the seats will go and hold the cockpit, while you move the aft main beam into place. Just make sure the four corners are all tied before everyone lets go... You can also do the job using trestles if you've got some about the right height.
I think my cockpit seat arrangement is similar to yours. I'm going to change it as I want to build in some storage, but I've not yet settled on a design for that part.
If you're ever in Hampshire you're welcome to drop by and have a look at Zest, if you want to get any ideas.
Thank you - will take you up on your offer as I am just near Frome.