Hello
I'm new to the forum
I have a G cat 5.7 which "blew up" on a very breezy day. Front beam tore the bow deck off the port pontoon. No one hurt and it was an epic pitchpole
I have been given a brand new pair of Hobie miracle 20 hulls and I wish to put the G cat cross beams, tramp and rig onto the new hulls. I am looking for any advice concerning the Marrying of these two boats. The rig sizes are similar and the beam hull connection is flush on both boats. ( aka - no posts as there are on the hobie 16)has anyone tried this before?
thanks

Norm

(removed dup)



Edited by MN3 on Jul 19, 2016 - 01:08 PM.

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beam tore the bow deck off the port pontoon.

How does a beam rip a deck off a hull?
was the lower part of the hull destroyed? if not it can probably be repaired

I am not sure about putting 19' 6" hulls (with centerboards) designed for 8' 6" Beams and a 31' mast on a boat that was originally designed with 18'7" hulls, 8' beams no boards, and a 28' mast.

my guess is you will be underpowered and your sail plan (assuming your rocking gcat sails) will not be optimal with those hulls and a 28' mast - but may not be a concern to you if all you want to do is pleasure sail

How are you going to attach the tramp? The gcat has holes drilled all around the decklid for stringing it up
the h20 doesn't have a deck lid

also putting a boomless sail plan on a boat rigged for boom has issues
the boom pushes the boom and causes rotation (which in turn creates a favorable wing shape at the front of the sail) boomless rigs can often lack in rotation. My friend who KILLS IT on his 5.7 has added positive rotation controls to his gcat to help with this (adding a rotator bar to the FRONT of the mast, adding control lines that run down the beam (in both directions), turn and down the deck to a little cleat so he can release and recleat EVERY tack. he occasionally forgets (or his crappy crew {me} forgets/screws it up) and it puts a very ugly shape into the mast. I am sure it could lead to failure if everything lines up perfectly bad.

I would personally search for a used gcat hull - there are lots of old gcats rotting away in back yards



Edited by MN3 on Jul 19, 2016 - 01:08 PM.

You're making a hell of a lot of work for yourself for a frankenboat that will never perform as well as either of the two original boats did. Getting the crossbars from a G cat to install properly and securely on a H20 is going to be a very involved undertaking, not to mention the tramp installation, shroud/forestay attachment locations, rudder installation, the list goes on and on. Really not a good idea if you ever hope to get back on the water in the near future.

sm

Thank you MN3

I only have the Hobie 20 Hulls, the rest of the boat is all G-Cat. I don't have a positive or negative mast tuning system, other than choosing which point in the boomless main's luff to attach the sheet. the mast pivots quite freely. As to reattaching the deck, I took it to a boat builder and he was the one that shook his head and offered me the hulls instead of a repair. Not sure how the forces loaded up to pop the deck but it broke off from hull at about the anchor point for the front beam. Probably some un-detected structural problem that was waiting to go.
The pitch poling may have done for the deck instead of being the cause

Thank You dogboy,

I agree I'm in for a project... either way I won't be back on the water this summer, not with this rig at least... I may grab a low priced H16 to stay afloat and then build the frankenboat... Nothing to lose by attempting the conversion (but time and some fasteners...) Maybe I'll make a photo essay for yucks and giggles.

Other thoughts from sailors are welcome.

N

Sorry for your misfortune, I'm always looking for Gcat 5.7 sails and parts if you decide to part her out.

where are you located Norm?

I'm located in Masschusetts, north of Boston

I'm located in Masschusetts, north of Boston

Do yourself a HUGE favor and sell the hulls outright. Then take the funds and scour the planet for another G-Cat 5.7 (or another boat). Your conversion project will cost you more money and heartache than it is worth.

FWIW,
Bob Curry



Edited by wxguy on Jul 20, 2016 - 10:15 AM.

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Master UniRig Sailor
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OOPS! Computer choked. Sorry for the double post.



Edited by wxguy on Jul 20, 2016 - 10:15 AM.

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Master UniRig Sailor
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svwindquest

I'm located in Masschusetts, north of Boston

Gotcha - I was gonna say i MAY be able to locate another hull for you but It is in florida

I have to agree with Dogboy and Bob - this project would most likely turn into a huge blackhole of time, money frustration and worst of all time off the water - and in the end, probably end up with a poorly performing cat

Unless you are a master fabricator, and want to invest a couple 1000 hours gelcoating and similar, i would part out the boats and buy something to get on the water (or buy something and turn this into a winter project)

Hmmm I hear the truth in everyone posts! I'm sure I'd give the same advice to my best friend...

buying another G 5.7: I've seen a small number of G 5.7's in various want ads. None near me.. Fla, Co, Tx, Travel and shipping will be more costly than the purchase. Nothing like driving half a continent to discover the rig you bought is not satisfactory. Or worse towing a new toy home only to have the trailer bearing go in Ohio... LOL My suspicion is that the adhesive on the hull/deck joint on this boat has expired. So I wonder about other boats of the same construction???

Once bitten twice shy: The boat was being sailed with a smaller main ( from a G 5.0 which serves as our first reef point) and the full G 5.7 Jib (since the 5.0 jib was in for repairs).. beams reach, very strong breezes. The front beam just peeled the deck off from is attachment forward. ( Too Much Jib .... Its Seems like the bonding between hull and deck is all based on the lip of the hull joining the lip of the deck. Most strain points are transferred to this lip with a piece of steel rod set in the lip and then the force is directed to the edge of the hull not the Deck per se... Can't imagine they can get inside and glass the seam from the inside... Its all academic...

Sell the new hulls: I would feel bad selling hulls which were given to me in the spirit of innovation... not all the ethical... bad Karma I'll ask the donor... what are an untouched pair of Hobie miracle 20 "racing hulls" worth??

Parting it all out: the G cat rig I have is okay. The main beam (and mast mount are solid). The running rigging is all newer Harken parts. Lines are older faded, Standing rigging is sound I have two sets ( one is way over built, made by the previous owner, I've seen lighter rigging on a 32' sloop) The mast is good, some minor torquing in the bracket at the point where all the hardware attaches but the rivets are firmly installed. the rear beam is sound. the main sheet traveler track is a little scarred, The main sheet traveler car is beat. The sails are functional. The G 5.7 main is functional but could use some reinforcement at the batten pocket ( luff end ) The G 5.0 boomless main ( my 1st reef ) is in good condition, the G 5.7 Jib is sound I just had a new full length zipper installed on it. the G 5.0 jib is in for repairs the head of the sail was beat up when I bought it. I also have a "boomed" main sail with a high roach shape ( my second reef, and a roller furling Jib from a hobie 6. ( had they been using the small jib I wouldn't be writing this post... LOL), Starboard hull - I imagine it is not worth much... Too skinny to make it a kayak..

Norm

I'm not familiar with what a G-cat crossbar cross-section looks like, but I can pretty much guarantee it is not going to be a drop-in installation on H20 hulls. That means you're looking at bedding the crossbar saddles and/or grinding away the existing saddles and re-building to make fit you G-cat crossbars. Then you need to come up with a way to attach the crossbars. The Hobie 20 front crossbar installs with four vertical bolts (two each hull) through the crossbar and into threaded backup plates in the deck. There are compression sleeves which keep the crossbar from crushing. The rear crossbar has a similar setup on the outboard bolts and a special bracket on the inboard side which allows the crossbar to attach to the side of the hull (so the main traveler can slide all the way to the outboard edge of the hull). If the G-cat crossbars don't align with these installation fittings (which I'm sure they don't), then you're looking at total customizing of the hulls and the crossbars to assemble the boat.

Then there's the issue of the tramp. If there is variation in the tramp length & width between the G-cat and the H20 (again, I'm sure there is), then you're looking at modifying the tramp (if your current one is too big) or buying a new tramp (if it's too small).

Then there's the issue of hull fittings. If the shroud and bridle anchors are different from boat to boat (again, pretty much a guarantee), then you're existing rigging likely will not fit and would either need to be shortened or new (custom) longer rigging purchased.

The G-cat has a boomless rig? Then the distance between the front and rear crossbar is critical for achieving proper sheeting angle. If there's variation between the G-cat and H20, then you could possibly be looking at needing modifications to your mainsail. Same goes for the jib - sheeting position, rake angle, size of the fore-triangle - it all comes into play.

Daggerboards - you said all you have is a pair of H20 hulls. So obviously G-cat daggerboards are not going to work with those hulls and you will need to source or fabricate dagger boards.

It's not as simple as just slapping on a set of H20 hulls and going for a sail. You would essentially be building a custom boat from the ground up.

sm

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I'm not familiar with what a G-cat crossbar cross-section looks like,

They are hobie mast extrusions

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width between the G-cat and the H20

8.0' vs 8.5'

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The G-cat has a boomless rig?

Yes - typically but there are gcats with and without

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G-cat daggerboards are not going to work

Gcats are daggerless hulls, symmetric shape

He would be better off trying to source a set of H20 crossbars. It would still be a total hack job, but at least the frame would be solid. Of course then you have to get a Gcat mast step to work on a H20 crossbar... it just goes on and on.... really bad idea.

sm

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.... really bad idea.

Or real strong challenge.
one man's nightmare is another man's dream

Hi thanks for the input.
>
> I realize the process would be a ground up build / pain in the A$$.
> I've built a couple of small boats using stitch and glue construction
> so I'm not uncomfortable spreading glue, glass and plywood around but
> your point about sheeting length based on trampoline length it
> important and not easily fixed, same with the jib / forestay harness.
> I assume there are hard spots in the hull to receive the bolts/screws..
>
> With respect to the bedding system, I had thought about making a thick
> west system putty with their chopped glass filler, sanding the hull,
> wrapping the beams from the G cat in waxed paper and creating a custom
> molded "bed" on the deck. The G cat has some cast pieces that match
> the interior of the beam and then the bolts drop through the deck. If
> the hulls permit access to these points then I could mold a block of
> westsystem and silica putty ( which essentially makes granite ) and
> then drill some hole and who knows...
>
> At the moment the new hulls are waiting for me, but I need my trailer
> to go get them and the pieces of my boat are on Cape Cod with my
> trailer... My poor brother borrowed the boat and I reassured him that
> and epic finish for a Cat is better than death due to being smothered
> by oak leaves, he feels really badly. I've been examining the blue
> prints for the H 20 hulls which show the layup of the interior. But
> til I have all the pieces in one place it will be hard to tell what is
> possible.
>
> Do you have any idea what a pair of untouched H 20 "racing hulls" (
> whatever that means) might be worth? Apparently these hulls were to
> replace some broken hulls that were being campaigned and the new hulls
> had blemishes, the owner insisted on perfect hulls and the blems went
> in the back of a boat shed.
>
> I have no aspirations to race, I just like to go fast and feel sailing
> machines work with the wind. My sons both study engineering but
> haven't much time to hang out and play with their dad anymore. I
> might be able to get them to fabricate some custom parts??
>
> I appreciate your interest, and support on the forum

Quote

Do you have any idea what a pair of untouched H 20 "racing hulls" (
> whatever that means) might be worth?

Really hard to say
your talking about a boat that is not in production, not a ton of them out there, not lots of people needing hulls

you can buy a complete used boat in good shape for $3,700
http://www.sailboatlistings.com/view/23932
one for sale on this site with 3 jib, covers and lots of extras for $4200
http://www.thebeachcats.c…14229-1993-hobie-20.html

I would estimate they are worth around $1000 per hull to the right buyer but you could have them for sale for a year or more until you find that seller (took me over a year to sell a working mysetere 5.5 for $1800 without a trailer and I couldn't sell it until I got a trailer