Hobie/J24 Trimaran Conversion

Right On.
Like-----Bin there, done that.

 

Bad Dog.
Will you be sailing your Dragonfly today in the 11.30 multihull race. ?
I watch that most Saturdays as I live directly opposite to the RMYC.

 

My neighbor, who has nutjob tendancies, just gifted me this conversion. Venture 21 less swing keel (replaced by daggerboard) with 16 foot long cat hulls. I'm a monohull guy and I had my doubts but I have to admit, it's a blast to sail. Pix attached for your viewing pleasure.

 

Glad to see it, I have a Macgregor 23 I've often thought would be a good tri as they are pretty tender with the keel. The down side is the small section mast . It's fine for a boat that heels in the puffs but I don't think it'll take the high loads for long.....

 

Hull Shape

It's good to see other transforming mono's into tri's. As for this boat it too could benefit from a modified center section of the Vaka.

 

I guess. It's a helluva lotta fun as is. Planes pretty easily and has a lot of giddyup. The real enjoyment from sailing a mutt like this is politely tolerating snide comments from blue bloods at the yacht club bar and then completely blowing them out of the water later in the day. He also gave me Chris White's book "The Cruising Multihull" and after reading it, I do believe that I'm about to drink the Kool-Aide on multihulls.

 

The ventures are a easy planing hull, nothing wrong with the shape except to fill in the recess where the keel used to be. Should go a lot faster than a J-24 conversion as they can pass 12 knots on a downwind plane stock. The 21 is the most dinghy like model but the others can plane too.

 

Fun

It looks like a lot of fun. Do you know if it has Tramps. Those are great for rail meat or sleeping on when camping. For those participating in the thread, what do you think about my recent plan to modify the Vaka?

 

Yes it has tramps. He used a section of old mast at the bow end for the front of the tramp and the rear is attached to the rear crossbeam. Also, the mast is from a catamaran-can't remember which one.

 

I'd find a boat with more of a planing hull and save on some work. Adding windage and weight is a hard way to try to go faster so you'd have to think about cutting the old bottom out. Remember you're carrying around a fiberglass layup that was designed to handle the racing loads of a keel. Taking out the swing keel trunk of a trailer sailor and putting a new bottom over the slot is a easier way to lose some weight though there needs to be enough support/stiffness for the bottom. Bulkheads should be glassed in where the akas are etc....

 

Could you explain? Do you mean bulkheads in the vaka where the cross beams attach for more stiffness? I'd like to upgrade my conversion since I've been so impressed by it.

 

In the Vaka, I'm presuming you are using beachcat amas with their stock aka attachment areas but if building from scratch those points need to be strong too. Boats like the Venture 21 typically had bulkheads (sometimes of not great ply) fastened in with machine screws. They can be relieved for passage but should reinforce both sides of the vaka as well as the deck. The aft bulkhead that supports the front of the cockpit back edge of the cabin should be upgraded to better ply and tabbed/glassed in too. The internal hull liner is plenty strong so it is OK to tab to it to avoid bulkhead print through on the Vaka skin. The deck,hull and internal liner are through bolted/screwed at the sheer with adhesive goop which may have dried out. If so it may leak at the sheer so use a adhesive caulk, you'll see where check a fastener for condition while you're there.

 

Thanks for the good advice. I would eventually like to take her out in open water but I'll be beefing her up first. Also, I'm toying with the idea of converting to a Chinese lug (junk) rig. Not the old fashioned kind but the modern cambered junk. I have Hasler and McLeod's bible but I'm unsure as to where to reposition the unstayed mast on a tri. Anyone care to guess?

 

They don't really work that well on multihulls because of the further forward apparent wind but I haven't really checked out the cambered version.. You need to be able to point, an unsupported luff tends to get turbulence. If you go to a free standing rig you'll need to beef up the area to put it because the boat isn't designed for it. If you are balanced now figure out your new rig CE and locate it in the same area as your current one.

 

I notice that Delane's link to his conversion on you tube has been deleted from this forum. Is it against forum rules to link to youtube? Just wondering...