Hobie/J24 Trimaran Conversion

[Delane]

More Progress,

Here are a couple of pics of the rear beam tie in. Adding struts or inner reinforcements to the front beam is next, followed by glassing and bolting up the Amas to the beams.

[Meanz Beanz]

I reckon that this will be really interesting to see how she sails. The J24 can plane as a mono with all that extra weight of the keel. Tris are traditionally built with very narrow hulls for all the obvious reasons... but what will be the reality of having an central hull with a bigger planning surface area? It might surprise in some ways, I can't wait to hear how it actually works... maybe we will learn something from Delane's efforts!

Cheers
MBz

[surf boat man]

hi there
I am doing something similar in australia.
I am converting a 26 foot surf boat (4 man + skiff row boat) into a tri. Using a hobie 16.

[Meanz Beanz]

Where abouts?

[Delane]

MBz,

Yes the jury is still out on the performance and only time will tell. I supect that anything from beam to broad will be exciting with at least 15 knots. I'm hoping that the transition from displacement to planning will smooth and without a large hump time.

Surf Man,

Way to go there. Sounds like it could really fly. Are you using a Hobie mast and sails also? Hope your Half Breed or Cross Breed turns out well.

[Hellkell]

Do you have the aluminum beams plugged so that water will not come through and drain into your center hull?

Nice looking work.

[surf boat man]

HI there Meanz Beanz and Delane.
I am in Sydney.
Yes I I am going to use just about everthing from the hobie 16. Hulls- one out either side, rigging and sails, rudders (two out back of the main hull) for a double rudder set up (should give a little more upwiind preformance and steerage), mast step etc. I might even used the tramp cut down wnd between each hull.
I am actually about to buy 3 surf boats. Another one I want to do an outrigger on just one side and swing up a lateen rig A real islander style boat that should still fly especially when the ourrig is on the windward side.
I am engaging with the forum for support, ideas's and run project reports.
I am not sure but I might start a new thread.
Its an interesting project becasue you can pick these boats up very cheap here. I paid $500 for my first surf boat and another 500 for the trailer. I figure I can buy a an old hobie 16 without a trailor for under a grand and hope to bring the whole porject (the honie hull one ) in at under 3,000.
Thats pretty good fopr a 26' tri on a trailer.

[waikikin]

Sounds like fun Surf boat man, I've seen those boats for cheap too, & read about someone turning one into a electric, maybe solar boat, post some pictures if you can or I might come for a look. All the best from Jeff.

[Meanz Beanz]

Aussie Surf Boat for anyone who has not seen one.

A surf boat trailer for $500... I would be interested in one of those! Any pointers? I'm in Melbourne but can pick up from Sydney.

[Delane]

Surf Boat Man,

Sounds like your on your way. Using the existing tramps is clever and probably needed. You might be able to get by with using one rudder or a slightly deeper one due to the length. But since you have them, might as well may use of them right. Those boats look really solid.

Hellkell,

Yes the beams are sealed with 3, 2 inches thick peices of foam. Also will end seal with the can foam for a final sealer.

[lane]

Your hulls look great. When do you anticipate having the rig up for testing?
Lane in Austin Tx

[Delane]

Hi Lane,

I suspect in a few months I'll be down to the last of the details. Waiting till near the end to assemble the furler, step the mast, position compression post and so on. Also dumping a lot of time and money into a home as well.

Laters

[catsketcher]

Surf boat man

Your tri is a god idea that has been done pretty well a few times. I would recommend that you buy a Hobie 18 as it has much larger floats and a larger rig. I got a friend a free surf boat and looked over a Hobie 18 version. It was featured in the Australian Multihull World mag over a year ago. It was a good boat.

I would stay away from twin rudders as the transom is pretty thin as you no doubt can tell. There is a fair bit of rocker in the main hull so the boats turn okay. Twin rudders only seem to be used on Open 60s which are very wide and heel a bit. If you put them on the floats then they will be a long way forward of the main hull stern and they won't turn the boat well.

The boat I saw used the Hobie 18 centreboards which worked well and meant that he didn't need to include a board in the main hull. If you go the Hobie 16 route you will have to include a board case which will compromise your interior.

cheers

Phil Thompson

[lane]

On using Hobie 18 hulls as amas, they are a far better choice than H-16 hulls. I used H-16 hulls, hopeing they would provide enough bouancy for my vaka. Carrying a load onboard caused significant submarineing of the leward ama, tons of spray and an upset crew. So, we now are rebuilding with H-18 hulls and hope for the best.

Good Luck,
Lane

[Delane]

Lane,

Sure, the H18 hulls will provide say maybe 15% more volume and should do the trick. Question: is there another solution. Maybe using tramps to reduce spray and try a little more weight shifting to the windward side or even trapezing. Might try extending the Amas out a little. Simple seems better for your already built design. Make it easy on yourself and explore all your options. My hulls are H20 and will provide about 2200lbs of bouyancy.