Quick building strategies

Discussion in 'Multihulls' started by simon, Oct 17, 2007.

  1. simon
    Joined: May 2002
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    simon Senior Member

    Hello everyone,

    thanks for the many interesting replies. I guess, as usual, there many paths that lead to the goal and there are many choices to be made.

    Lots of the posts mention flatpanels for the ease of fairing and infusion is in the favor of many.

    The idea of having a round bottom constructed separatedly seems interesting, as taping up several board to form the bottom, probably consumes also time and the difference will not be huge.
    Producing flat topsides, decks, superstructure, (with infusion?) will cut down time.

    What would be the options in technical installations like engines, rudders, daggerboards/keels, rigging and deckgear, to keep it simple, reasonably cheap and efficient for building?

    I would be interested to hear from people that have finished the project in a short time and also hear about their choices.

    A nice day to everyone

    Simon
     
  2. doug kay
    Joined: Oct 2007
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    doug kay Junior Member

    I like the strip cedar constuction for the hulls, it's easy and it's quick. Building the hardback took about 30 hours for my 30 footer. Laying up the strips needs some preperation to avoid a lot of sanding later by designing some method of alighning the strips along their length, they tend to spring. I simply cut the heads off copper nails but some builders use round and cove others tongue and groove but try different methods before you procede. You should have a hull in the rough after 20 hours or so. You then apply glass cloth, I used bi-axial and epoxy resin which resulted in an enormously strong hull.
     
  3. rob denney
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    rob denney Senior Member

    G'day,

    With KSS at least some of the shape of the topsides comes from the bending of the area below the topsides. You would get less shape in your topsides if you table infused them seperately. You are also making extra work, for no real gain as the interior of the KSS hull is very accurate above and below the waterline.

    You did not tell us what your friend disliked about KSS?

    regards,

    Rob
     
  4. catsketcher
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    catsketcher Senior Member

    Interiors are time thieves

    The bloke who ran the workshop here had to spend a long time time fairing the boat after the workshop finished and the hulls were not exactly identical. I started my first folding cat about the same time as him. I have been sailing two and half years and he is still long way off. This has far less to do with KSS than with the time he spends on the boat. Having said that KSS won't make your boat happen overnight. You still have to put in hundreds or thousands of hours.

    The infusion runs very well. I have seen hours of video of the process and my friend swears by it - it looks good.

    I think Rob and I will have to agree to disagree over this one. I build cruising cats which have lots of interior even on the simple ones. I like to reduce the build time by leaving sides off and fitting interiors on a minimal shell bottom. It is also what Craig Schionning does on the Spirited 380. This build time will be the major part of the project so reducing interior time is important. Getting a hull done quickly is not going to get you sailing sooner if that method makes fitting the interior longer. Go and have a look at the method Craig and I used for our cats and see how easy it is to fit a floor when you don't have to stand on it and how quick it is to fit furniture when you stand on the shed floor and not in the boat. If a quicker interior method can be coupled with large panel infusion then I think that is a good road to proceed down. I am sure that large infused panels can have slight camber built into them by making the table slightly curved. This approach is old - Constant Camber and Varicam are methods that tried this before and it worked - they didn't use composites like foam and also tried to incorporate the rounded hull bottom into the mould. This forced the designs into certain constraints.

    Rob's boats are minimalist and a world away from the cats I build. They (at least the leeward hull) are mostly hull and as such a timely hull building method will work wonders.

    The proof will obviously be in the pudding. The only KSS boat I know is still two hulls years after starting. The Space 55 that was the first KSS boat in Australia was not in the water quickly either. All new theories have to be proven before they are accepted by the majority. When a 12m KSS boat gets sailing in less than 2000 hours with a good interior people will take notice and change their ways. Until then there will have to be conjecture and good mannered banter.

    cheers all

    Phil Thompson
     
  5. rwatson
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    rwatson Senior Member

    For what its worth, the KSS method has been constantly on the improve over the years.
    Rob Denneys Proa is not a KSS design, he is just adopting the KSS methodology, because he has *done* strip planking in a big way and has nothing to prove his credentials as knowing the better way.
    I agree that aspects of the KSS method some years ago had some critics - though none of their comments would have stopped me.
    The new methodology is even better, and I am keen to use aspects of it for my next boat (not a cat)
    I have never come across a faster method for a quality result than KSS - bar none.
    Being close to completing a strip plank smaller boat, my experience is if you want the nice wood effect good luck to you - its a bugger of a way to do boatbuilding. For my money, a self build sailboat has to be either ply, or prelaid panels (like the KSS) or you are a masochist. You might talk me into steel for a big project too.
    In any event, all the best for whatever you do - it can be fun.
     
  6. Fanie
    Joined: Oct 2007
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    Fanie Fanie

    Hi Rob, I am aware of how the process works, and yes, it is easier than to run around with rollers and buckets of resin. It is not so easy however, if an area gets an air pocket enclosed in resin, ie the resin flows around it instead of through it, you would have to rework that dry area. Any way around this ?

    I have also seen a cheap rope 'net' made around the subject to be resinned to better flow. Getting the plastic to seal all round can be difficult sometimes.

    I have vacuum pumps I can use. If one can know where the problem areas are going to be it would be easier.
     
  7. yipster
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    yipster designer

  8. rob denney
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    rob denney Senior Member

    G'day,

    Yes and no to the KSS proa. Derek reckons he can do pretty much any hull shape, (including monos) but then made a good case to use the shapes he had used in the past (slight V, slight rocker, flat decks). I figured it was worth a try, so went with his shapes. Whether they work or not, time will tell. Having seen the system, there is no doubt that our standard hull shape (semi circular sections, no rocker) could very easily be produced using KSS, in one piece, with very few, probably zero cuts.

    The rest of your post is spot on. The knockers have never seen it in action, so can't/won't believe it. Derek's latest trick with torturing the foam takes the system to a new level.

    regards,

    rob
     
  9. rob denney
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    rob denney Senior Member

    G'day,

    This was one of the highights of the workshop. There was an area where there was an air leak (hole in the plastic) near the edge, so the resin was not being sucked. Derek took a vacuum line, cut a hole in the bag and shoved the line in. It wet out immediately. Remove the hose, tape over the hole and the job is done. He also reckons he has never had a failure wetting out and bagging dry spots post infusion. Guess it is debatable whether this is more or less strong than cutting out the dry bits and patching them. Was not an issue on any of 4 hull sides, 2 decks and a pile of smaller parts.

    The wet out is pretty uniform across the job, and air pockets are unlikely. This is not the case with in mould infusion, particularly with segmented core on tight curves. It is also very easy to follow the wet out and ensure it is complete. After your first test piece, you will be an expert. After your first hull, you will be ready to write a book on the subject.

    Sealing the perimeter is easy as it is all on a flat shiny table, with no resin, unlike conventional vac bagging, which can be a nightmare. We used brown packaging tape and masking tape for most of it, vac tape for the rest. It is important that the bag has plenty of slack, but this is much easier on the flat than on a mould, particularly a female one. And there is no rush, unlike conventional vac bagging.

    We used scored perforated foam on the lee hull. Worked well, but is expensive and the scores were too big so we have a bit of extra resin. On the ww hull, we used cheap shade cloth and perforated foam. Worked superbly.

    Definitely easier. Also cheaper, lighter, quicker, more uniform, cleaner and there is no contact with smelly resin.

    regards,

    Rob
     
  10. Bruce Woods
    Joined: Sep 2007
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    Bruce Woods Senior Member

    Quick build stratagies.

    So most seem to agree that the hull skin is only a very small portion of a completed cruising multihull. Yes I understand Rob has a vested interest in pushing the KSS system so only highlights the positives and sells the possibles as do-ables. After reading the Mark Giles article on the recent Australian KSS workshop one is left wondering what the system advantages actually are. Quote .... Derek (kelsall) confirmed that a good paint system is essential for a lasting and attractive job. unquote. (topside print through and kerfmarks require fairing out)

    Rob quoted in a post as saying the system adds substantial cost through licence payments and design mods to Dereck.

    So one gets a limited hull shape at extra cost that still needs fairing and painting.

    Having a commercial back ground in infusion moulding I must question the advantages for the first time back yard builder(you get to stuff up a lot of expensive materials quickly if things dont go quite right like a power failure during infusion for instance). Even using this technique you are still going to get covered in the sticky smelly stuff, Gelcoating, surface tissue application to try and stop print through , glassing the darts, hopping in the hull to glass the keel join , bulkheads, furnature etc etc etc...... And then theres the pile of consumables that end up in the trash can ( read money)

    Regards
     
  11. rob denney
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    rob denney Senior Member

    Phil
    The bloke who ran the workshop here had to spend a long time time fairing the boat after the workshop finished and the hulls were not exactly identical. I started my first folding cat about the same time as him. I have been sailing two and half years and he is still long way off. This has far less to do with KSS than with the time he spends on the boat. Having said that KSS won't make your boat happen overnight. You still have to put in hundreds or thousands of hours.

    Rob
    You denigrate the system, then blame the builder. Nobody said KSS would give you a boat overnight, just many months less than any other method.

    P
    I think Rob and I will have to agree to disagree over this one. I build cruising cats which have lots of interior even on the simple ones.

    R
    Sorry, this is a contradiction. Simple boats don't have lots of interior.

    P I like to reduce the build time by leaving sides off and fitting interiors on a minimal shell bottom. It is also what Craig Schionning does on the Spirited 380. This build time will be the major part of the project so reducing interior time is important. Getting a hull done quickly is not going to get you sailing sooner if that method makes fitting the interior longer. Go and have a look at the method Craig and I used for our cats and see how easy it is to fit a floor when you don't have to stand on it and how quick it is to fit furniture when you stand on the shed floor and not in the boat.

    R I may be wrong, but i can't see the time saved in installing the floor making up for the time spent planking, glassing and fairing the bottom of the hull, then attaching the topsides. And fitting the interior to the floor means you then have to fit and bond the hull sides to all the edges, and cut away the interior to bond the topsides to the bottom. Apart from the floor, this cannot be as quick as dropping the precut, prefinished pieces into the complete hull, filletting them in place, then gluing on the deck using a premade deck edge radius. No idea how Craig does it, but any labour savings don't seem to be reflected in the selling price.

    P If a quicker interior method can be coupled with large panel infusion then I think that is a good road to proceed down. I am sure that large infused panels can have slight camber built into them by making the table slightly curved.

    R Sure, you can build a curved table (with difficulty), and you can strip below the waterline, then join the two together. But why bother, when KSS does it all in one hit, in much less than half the time, with much less than half the hassle.

    P This approach is old - Constant Camber and Varicam are methods that tried this before and it worked - they didn't use composites like foam and also tried to incorporate the rounded hull bottom into the mould. This forced the designs into certain constraints.

    R Derek reckons, and I agree, that there are no cat hull shapes (and not many mono ones) that KSS cannot produce.

    P Rob's boats are minimalist and a world away from the cats I build. They (at least the leeward hull) are mostly hull and as such a timely hull building method will work wonders.

    R My boat is minimalist. The rest of the harryproa range are comfortably fitted out cruisers, designed to be easily built, so much of the fitting out is structural, and modular. This also keeps the weight down.

    P The proof will obviously be in the pudding. The only KSS boat I know is still two hulls years after starting. The Space 55 that was the first KSS boat in Australia was not in the water quickly either. All new theories have to be proven before they are accepted by the majority. When a 12m KSS boat gets sailing in less than 2000 hours with a good interior people will take notice and change their ways. Until then there will have to be conjecture and good mannered banter.

    R Phil, you are a bright guy, with a very clever boat, and I don't want to get into a pissing contest with you, but you are kidding yourself on the KSS vs other methods argument. You have blamed your mate for his boat taking so long, and the Space 55 was built by a bunch of Gold Coast clowns 10+ years ago. KSS has improved a lot since then. It ain't conjecture. Do yourself a favour and give it a go.

    regards,

    Rob

    cheers all

    Phil Thompson[/QUOTE]
     
  12. rob denney
    Joined: Feb 2005
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    rob denney Senior Member

    1) Try telling anyone who has glassed, filled and faired 2 cruising cat hulls, decks, cabin top and bridge deck (all of which can be built with KSS) inside and out that it is "a very small portion of a completed cruising multihull".
    2) I have no vested interest in KSS. Or any reason to push it apart from trying to make life easier for other builders. The license fee goes direct to Derek. All our plans are for strip plank timber. I strongly resent your insult and ask that you retract it.
    3) A gel coat finish seems fine for 95% of the boats in the world, but a quality paint job will give a better finish. Check out the gel coated Toowoomba boat mentioned earlier.
    4) Hull shapes are not (for the nth time) limited.
    5) The cost of the licence is higher than I would like, but is more than offset by the labour, mess and cost savings. If you are that much of a penny pincher, run a workshop and get Derek and a bunch of others to pay to help you build the boat.
    6) There is a huge difference between flat table infusing and in mould infusing. Anyone who wastes materials with KSS is not following the very simple instructions.
    7) Power cuts will muck up infusion. This is definitely a reason for spending 6 months of your life filling and fairing unnecessarily. If you are this paranoid, buy or hire a genset.
    8) Read Mark's article. Nine of us went to dinner at the flashest restaurant in town after 3 days of infusing, in our work clothes.
    9) Yes, there is some additional glassing and fairing to do and yes you will have to glass in your furniture, although what this has to do with building the hulls is beyond me. I never said KSS was perfect, just a hell of a lot better than anything else.
    10) If you can't see the advantages, buy yourself a dust mask and a Tyvek suit and get started strip planking your boat. Makes no difference to me.

    Regards,

    Rob
     
  13. catsketcher
    Joined: Mar 2006
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    catsketcher Senior Member

    My last word

    The last thing this discussion needs is a long running argument developing. I am going to agree to disagree with Rob in this one and wish him well in his endeavours.

    Diversity is a great thing.

    Cheers

    Phil Thompson
     
  14. rapscallion
    Joined: Oct 2006
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    rapscallion Senior Member

    I like the idea of using the KSS method with Nidacore; or using a version of cylinder molding with nidacore and resin infusion. Nida is great stuff, and dirt cheap. Sherman Williams has some great marine epoxy that is much cheaper than WEST, and the stuff looks pretty good to me.
     

  15. Bruce Woods
    Joined: Sep 2007
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    Bruce Woods Senior Member

    Quick build stratagies

    Hi,

    Rob states " This is definitely a reason for spending 6 months of your life filling and fairing unnecessarily".

    For a couple of cat hulls?

    Come on Rob quit the exagerations , It certainly doesn't help. Then again ,after seeing the fairing on a couple of your creations I suspect you simply have no idea regarding fairing so we'll let that one through to the keeper .

    Regards.
     
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