Catamaran plans, who have I forgotten ?

I would think the bulkheads in foam would be about the same as those on the tri-star 31 as displacement is not that far off . Scantlings and foam size as well , bottom of the hulls would need to be built up to about 1/4" or more for puncture resistance . Substituting woven and mat on the 31 I bought 17oz 45/45 and 18oz 0/90 for outside skin , 17oz and 12oz 0/90 for inside , 6 oz S2 glass for a finish cloth and a 3of S2 glass for the first laminate over the foam . triax would have worked , Iwould have had to add thickness to the bottom of the hulls to satisfy Ed . I think 5/8" foam would be fine on the hulls , bulkheads will have to be a bit thicker with two layers if I remember right , i would have to look at the foam bulkhead plans to be sure .

 

I'm not sure I understand what you are saying.

1/4" on the bottom of the hulls ? Surely you don't mean 1/4" skins ?

All the above if I understand it correctly is MUCH heavier than most boats I've looked at.

I have plans for several boats in this size, both tri and cat and they usually use 12mm foam with 600gsm glass either side. Depending on your build method sometimes scrims or cover layers are added but for infused hulls they are not really necessary.

Rob Denny goes further with 400 gsm skins on his proas.

I love the EH boats but the accommodations on the tries won't work for us (I think) and he jumps straight from the 28' cat to over 10m which is too big for me.

Oldmulti and others: I have a question. I know build times are highly variable but I would still like to ask for opinions on how long you think it'd take to build that hull only. I've done fit outs re-rigs etc, but actually building the hull ready for paint, assuming I'm working solid 8+ hour days 40 hour weeks with a well equipped shop. Any thoughts on time to build the hull/s ?

 

Hi to all. At one point in my life I knew Lock Crowther well. I had several designs done by him. He asked a question one day do you want a racing hull or a cruising hull for the same design. The racing hull was built to the strength limit of the glass layup but would have a thin outer skin and would require repair if you hit anything solid. Being foam glass only the outer skin was likely to be punctured and it still would be water resistant until you got home. A cruising hull would have extra layers of glass and be PARTIALLY puncture resistant, not bullet proof. Foam glass is a different mix to EG plywood.

Now we get to some numbers. Catalac 9 Mtr Displace 11,000 lbs had 8 mm solid glass skins. Seawind 31 Displacement 8000 lbs had 4 to 6 mm solid glass below the waterline with 440, 600 gsm 12 mm foam 600 gsm, 400 gsm in the hull sides. Sunstar 32 displace 8400 lbs 225 CSM 800 biax 12mm foam 800 biax. Eclipse 32 displacement 8200 lbs solid glass below the waterline 3 to 4 mm thick. Summersault 33 displacement 8900 lbs 225 csm, 750 triax, 12 mm pvc, 420 gsm biax.

Shuttleworth 31 displace 7500 lbs 800 gsm 15 mm foam 600 gsm in hulls. Non structural Bulkheads 600 gsm 12 mm foam 600 gsm. Structural bh's 800 gsm or 2 x 500 gsm uni 12 mm airex 800 gsm or 2 x 500 gsm uni with a top and bottom flange. Underwing 2(400 gsm biax) 20 mm foam 2(400 gsm biax).

Romany 34 displacement 9000 lbs if done in epoxy 600 gsm biax 12 mm airex or corecell, 600 gsm biax.

I hope you understand that different designers have different assessments of hull structures. Most of the foam glass hulls here are 1 mm thick on the outer skin, some solid glass hulls are under 4 mm thick in total. When cats were being first built in the 60's they had really heavy 8 mm thick solid skins, designers have learn a lot since then. Now my final word the OMRA 60 tri's and 110 foot Club Med cats had 600 gsm high strength carbon fibre skins in epoxy either side of thick foam (resin infused cooked in an oven for hours). It is possible to do very light skins if you use the right materials.

 

I didn't know eclipse was available as solid to the chine. The materials list on the Woods website details strip..

Sailing Catamarans - Sailing Catamarans

 

Guzzi3. You need to read the Woods builders forum and you will find that several builders have done variations (with Richards approval) of the various hulls. EG there have been Gypsys hulls built in ply, solid glass, foam glass etc. in either round bilge or chine hull. Each has been done based on available materials, builders skill or preference etc. Mr Woods is flexible and if he trusts the builder, he will do a fast redesign of EG hull skin structure.

 

Yes he is a lot more open to builders needs than a lot of other designers.

Have you any comment on my question above about time to build the hull for the 880 ?

 

The original Eclipse was built by Richard with solid glass below the knuckle,plans show cedar and 600g skins as you mention Guzzi.
Cedar can be exchanged for boat building foam , I would prefer the solid glass ,say three - four layers or more of 600g bias 45/45 ,I believe I recall that is what Richard recommended ,he also didn’t recommend it to me as it was too heavy in his own words ,making one wonder why the he would use it,I like the solid glass version below knuckle. Found stripplanking a chore in that area ,could have used male mold to lay glass over if we were to do it again.( won’t be)

 

I think the best comment on building time I heard about was from a woman cruising monohull builder after turning out a Lyle Hess cutter in 8 years. When asked if she felt that was too much time she replied that it would have taken 8 years for her not to build it too

So...... Somewhere between infinity and one grasshopper.

I use chart tables.

 

Study plans for the 31 showed 1/2" foam but plans call for 5/8" , 1/4" glass is at the keel area and just above and can be made solid glass , I think the outside skin call for 24oz woven with mat , even with a 17oz biax combined with 18oz biax I would have been lighter when the weight of mat is taken into account after sucking up epoxy . I had no problem with it being built with a little more glass , it would still have been lighter that the ply version .

 

This is not really a positive thing. Catamarans are too weight sensitive to really change much.

The 880, in composite, 6000-10000 hours, 8000 average. 60 hours work weeks, 3 years. Site challenges, as in the build cannot all be inside a climate controlled area, add a year depending on locale.

3 years for a physically challenged man, minimum, more likely 4

For plywood, take a year off. Okume, sheathed with glass is the best way for an amateur to build. Foam is just so, so, so much more work. Consider the stack on each panel alone. Bag setup for infusion. All much harder than bonding and sheathing a whole hull..watertight hulls, a build you control make okume a winner time 100.

 

Ply is not an option. I'd rather kill myself.

1. It is much much dearer than foam.

2. The boss won't put up with the smells of a timber boat.

3. Past experience. Cosine wherry, yes. Maybe even a ply pram, but a big ply boat. Absolutely not.

Wow. 8000 hours ? Just to build a shell ?

rberrey: How long did the Horstman hull take ? Also what is the payload of the 31 ?

 

In the early to mid 1980,s I knew 3 men working part time who put 3 , 58' shrimp boats in the water building with C-Flex in 4 years . The 4th boat was in the mid 30' range and completed to the diesel being installed , Johnny died , then Doc , and the 4th boat was worked on by my neighbor off and on until a couple years ago , he asked if I wanted it , it got cut up and hauled to the dump . Completion time depends on method and means , skill level of the builder and complexity of the build , and time , as it seems to run out . I backed out of building the Horstman , lost my free dock space , I could give you a deal on some older 5/8 H80 and 80 gal of Silvertip if you were in the U.S . My uncle built a 22' sailboat over a two year period using C-flex , If my aunt had let him buy all his material at once the he would have finished in 6 months .

 

Thank you for that. I thought I might be able to build the hull/s in about a year full time ready to paint. I guess that's unreasonable.

Seems crazy that it takes this long. I'd be building in my front yard so no commuting...

Sailing Catamarans - How long does it take to build?

2500 hours is doable, 8000 not so much..

 

Disp is 5500 lbs , I think useful load is 2000 . A guy named Steave Janes ? built a tristar 49 , another boat wrecked it so he scraped it and built a 31' with the salvage and sailed around the world . A letter he wrote to Ed talking about upgrading to the 35 " I 've got zoom a bit overloaded , fully ready to cruise with water capacity 0f 60 gl. , lpg 15gl. fule 15 gl. lots of spare rigging , 5 anchors & chain , miles of line , 14 sails , 3 sea anchors , lots of tools and paint , solar panels " , you get the idea , he lived and sailed on the boat for years . He stayed in the Med awhile and the couple that built the 31 in the UK did so after meeting him and his boat . He then went to the Carib and road out a hurricane on the boat , may have been in the VI . If you talk to or read what Horstman owners have written about their boats it,s easy to get sold on them , but they tend not to sale them . The Guy that scaled the 28' to 30' told me it was fast but too small to cruise long distance , he thought the 31 was fine and Steve Janes travels over the years pretty well confirmed it .

 

1200 hrs to build the tristar 31 , thats 23 hr,s a week for a year , double to 2400 hrs and work 16 hrs a week and you finish in 150 months , a little under 3 years . 1800 hrs at 16 hrs is a bit over 2 years . All your material on hand and your ducks in a row I think it can be completed in under 2 years .