Kss Kiss Kat?

Discussion in 'Multihulls' started by ThomD, Oct 1, 2015.

  1. ThomD
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    ThomD Senior Member

    Have any of these been built, or for that mater have any of the other KSS boats been built. Basically the best integrated system, even though I am mostly a wood builder, fair is fair. Iconic designer who has stayed up with the times, but where are the boats, good Youtube videos, build alongs. Seems relatively furtive for an industry leading system. In fact I see more from people using KSS to make boats other than Kelsalls, than Kelsalls themselves. Maybe they bang them out and are off cruising. A nice Cat was built under my nose locally, and I am dismayed to have missed the whole thing, so I know it is out there happening, just wondering where the nexus of online activity is.
     
  2. redreuben
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    redreuben redreuben

    Well apart from the fact that the new KSS cats are frightfully ugly, US$6000 for 30 ft plans is just, well, "not realistic"
    Derek has an amazing portfolio of cruising designs for foam and timber that he said was going to be adopted for the new method but it never happened. The person who has really made the most of Kelsall's method is Rob Denney.
     
  3. rob denney
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    rob denney Senior Member

    Thanks Red.
    The benefits of KSS are only outweighed by the range of possible variations on it.
    These are what we have concentrated on, to the point that we can now build and fit out harryproas with minimal (theoretically none) cutting/grinding/sanding of cured laminate and no post infusion laminating, filling or fairing. Everything is completely laid up in the infusion and glued together using slots or male/female joins, which are also included in the infusion.
    Some examples of what can be done are http://harryproa.com/?p=994 (40'ter, plans are $AUS4,000, $US2,800) and http://harryproa.com/?portfolio=harryproa-cruiser-60 (60'ter, plans $AUS7,000/$US4,900).
    The result is no dust, sticky mess or need to get suited up to work on the boat and a huge reduction in wasted material; eg less than 50% of the resin used in a conventional wet laid or vac bagged equivalent.

    It also means a lot less labour, and what there is, is less strenuous.
    Strip planking (and ply) involve millimetre accurate frame cutting and setting up, screwing/unscrewing/filling hundreds of screw holes, working fast to keep up with resin going off, washing off amine blush, and endless filling and fairing. Most of which should be done while wearing a full suit, gloves and respirator.
    Intelligent infusion uses a simple, self aligning mdf or similar mould. The lee hull mould for the above boats requires 7 measurements, 3 straight cuts, 2 curved cuts and 2 fillets. The mould does not need any fairing, polishing or waxing, but does need to be sealed so it is airtight.
    Both skins, the core, extra reinforcements, rebates for doors, hatches and windows, joins, bulkhead landings, solids for deck fittings and any internal finishes (woven carbon, formica, veneer, etc) are placed in the mould, along with the infusion plumbing which is all hardware store bought.
    This is easy work with dry materials which are cut with scissors or a utility knife. No stress or mess and very little measuring.
    The dry laminate is then covered with a vacuum bag which is sealed against the mould and vacuum applied. This is a much more leisurely task than rushing to do it while the resin is curing.
    Once you are happy with everything, resin is mixed and sucked into the laminate.

    40 minutes later, the entire half hull is wet out with the correct amount of resin and no voids. Remove the peel ply and it is ready for painting, inside and out. If the idea of mixing and using 20 kgs/45 lbs of resin at a time is scary (it should be the first time), it can be done in stages, down to as little as 600mm/2' of hull at a time with mixes as small as 1kg/2.2 lbs of resin.

    The beams are built the same way. On the folding 40, the hinges are included in the infusion using carbon tow.
    Flat surfaces (shelves, bulkheads, bunk tops, bridge deck, walkway etc, are made on a flat table. The foam is cut to shape (mostly straights and radii) and door ways, hatch openings etc cut, along with the doors, hatches and any edge treatment (lips, joins, sealed edges). These are infused, taken from the table and glued into slots in the hull, etc. No cutting, shaping, filling, edge sealing, filleting, tabbing or fairing required. The hatches and doors are a perfect fit and ready to install.

    The mould for double curved surfaces such as the cabin roof on the Cruiser 60 are essentially the same, but require a little more work on the corner fillets. As they are external, this is pretty straightforward.

    Masts can also be infused, but we are now supplying them as joined filament wound sections, which are lighter and about the same cost as owner building.

    rob
     

    Attached Files:

  4. groper
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    groper Senior Member

    As im nearing the completion of my 35ft cat build, using my own version of KSS, i thought id add a couple things to this discussion...

    1. I took the approach of infusing huge panels and cutting them up into the peices i needed, then glass filletting and taping everything together. Whilst the infusions and assembly went very quickly, now i have to deal with the aftermath of fairing out a million linear meters of fiberglass tape joins.... im realizing that ive probbaly lost everything that i gained with my initial speed, infusing a huge full length panel only took me 4 hours from applying mold realease to clamping off the lines and leaving it to cure.

    2. Eliminating the print through from the flow media. I didnt think this was a major problem at first, but ideally you need both surfaces of the panel to have a flat finish, not just 1 good side. Now i have to bog every visible surface which has the flow media print on it.

    3. Filletting and taping. This is not such a big deal in itself, but dealing with the coves and corners getting it all ready to paint after the fact is a huge task. Would be much better if all the coves and corners were finished and ready to paint without all the bogging and sanding.

    If all the above are solved without too much extra work setting up the infusions, then its definately worth going for...
     
  5. ThomD
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    ThomD Senior Member

    I'm a fan of infusion, though I can't get past the 50 cent a square foot cost of ply in my neighbourhood. I do think it is a little inaccurate to talk about how long it takes a panel to infuse, there is a lot of work and fairly specific workplace that needs to be done, and be available.

    Even building in ply there are certain steps where huge progress can occur. I have personally made amas in 1 hour a foot, to completed structure, ready to fair and paint, and competent worker can fair the ama in a few hours, and one needn't sand it much at all. Ply (and strip) also nest very well with productivity improvement from CNC. If one is going spend 6K on plans, and a few more K travelling to workshops, that is a 4x8 gantry machine from CNC router parts.

    Not comparing ply to KSS, just saying that in the last 20 years there has been a huge improvement in the productivity of several other boat building methods, and we often compare the lattest acheivements in one method to the oldest version of another which is fair enough since a lot of people are still building in the old way.

    But I guess my point in this thread was to ask where are the KSS boats and builds. I follow Rob's work a lot and have run across a few other people who were doing their own KSS boats to their won designs, or anothe designers designs. What about the KSS boats?
     
  6. rob denney
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    rob denney Senior Member

    I find it is less work, dust and waste to cut the foam to shape, then infuse it with the edges sealed, lipped or rebated and any openings included in the infusion.
    Including in the infusion the items that go in the openings such as doors, hatches, etc takes very little time, uses the foam cut outs and ensures a perfect fit when finished. Adding flanges and finger holes to hatches, solids for screws and rebates for hinges and handles is a lot easier dry than post infusion.
    Infusing multiple pieces with independent feeds under a common bag eliminates problems, allows plenty of time and results in pieces that go from table to boat with no trimming or finishing required.

    Scored core prints less (but must be fully cured before painting, especially if it is an ester resin), a decent undercoat should be enough. Thick peel ply and perforated thick plastic also help.
    If you want it really glossy, either a sheet of flat material over the job (practice first, there are some traps), or do it in two hits.
    Media print through should be proud of the surface, so you should be able to sand it rather than fill it?

    Not such a big deal, except for the ones that are overhead, in tight corners, hidden or below knee level. The rest are easy enough, but still a lot of sticky work.
    Not quite relevant to your boat, but a mast client built a 12m/40' panel cat, reckons he used an extra 200 litre/44 gallon drum of resin and a roll of cloth on the taping and filleting.

    The only job worse than fairing the outside is fairing the inside, which is largely eliminated by including the landings in the infusion. No filleting, taping or fairing required. Just glue the bulkheads in the slots, wipe off the squeeze out and give it a light sand before painting. This is easy on harryproa hull shapes, not so much on conventional catamarans.

    These, and a lot of other problems have been solved or eliminated. Definitely worth going for.

    It is often said that infusion has more waste than any other build method. This used to be the case, but no longer is. Infusing both skins and the core in one hit, scored core instead of infusion mesh, reusable plumbing, cut offs close to the resin inlet and infusing to an edge means that only the bag and tacky tape are thrown away and the only cloth that is wet out is part of the finished job. The small amount of resin in the plumbing (50g per metre) is less than what would be on the floor and in the application tools and containers after a day of hand laminating.
     
  7. groper
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    groper Senior Member

    I'd rather fill a printed panel as opposed to sanding it flat, the cured resin is way too tough to sand down.

    I agree with most of your ideas rob, i couldn't do alot of what you described because I didn't know the final locations of many things. I was figuring it all out as I was building, making changes etc. If working from a 100% completed design, then alot more work could have been done pre infusion and saved time for sure...

    Have you had an engineer look at your bulkhead slot bonding method and given it the thumbs up?

    I totally agree with designing the shapes with these things in mind, for example you can't bend a panel transversly to the slot in it- the slot makes it too stiff... so why create that shape in the first place! With a bit of thought, simple to build shapes can also look good too! I can see this approach in all your designs and it's a great way to go, effective design which is mindful of building time - which is the biggest dilemma in building boats.... I swear I was going to go overseas and project manage my next build, outsource the labour to a small army a be done with it in 6 months... :D
     
  8. rob denney
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    rob denney Senior Member

    Peel ply more than pays for itself from savings of sandpaper, bog, time and effort.

    Intelligent infusion and box moulds makes designing more challenging and more work goes into the plans, but the savings for the builder are enormous.

    Yes. Structurally, they are the same as bonding to a solid glass hull. The worry was the location and alignment to minimise the thickness of the glue and keep the bulkheads square to the boat. These have been resolved, the glue lines are very thin and the alignment better and easier than a conventional installation.
    For light laminates or thin cores, the slots are on the inner surface and the core continuous. Same as fillets and tape, except the fillet is foam, there are no glass overlaps, the glass is all integral and the edge of the bulkhead is glassed and glued to the job as well as the sides. And, of course, there is no sticky or dusty work.

    Exactly. KSS is great, but it is limited as there is not much you can do to panels which will be bent. Any cutouts, rebates or extra laminations will screw up the fairness of the bend. Simple box moulds open up a huge range of options for speeding up the process, saving materials and time and generally making the whole process more enjoyable.

    Ta.
    The biggest time and money saving you can make will be to choose the right build method. Second biggest will be choosing the right boat type, ;-)

    Not inaccurate at all. The prep time for an intelligent infusion is significantly less than other methods, and the tasks are easy: cutting dry cloth, plastic sheet and foam and laying them in a simple to build mould at waist height.

    The time, effort and mess saved by the actual infusion is icing on the cake. Mix a bucket of resin/hardener, put a hose in it and watch the glass absorb about half the amount of resin you would use in a hand laminate, join the foam pieces (no scarfing or butt blocks), seal all the edges, reinforce all the highly loaded areas, complete the doors and hatches, locate and align all the bulkheads, shelves and solids, make all the holes and rebates, and complete ~90% of the construction. All completed in not much more than the time it takes to make and drink a cup of tea. Ply, strip, KSS and even many production builds simply do not compare.

    Infusion in a box mould requires the same amount and type of build space as a ply or strip hull. Less if you are scarfing the ply sheets off the job. It is also unaffected by humidity.

    CNC cutting is great, but I reckon it is more interesting to measure, cut and assemble the ply than it is to epoxy, sheathe and fair it. Better to spend the money paying someone to do the messy, toxic jobs, and do the interesting ones yourself.
    We cnc cut the foam for the first KSS workshop we ran ~10 years ago. Saved a bit of time, cost a lot of money. It's certainly not worth the cost with the simple shapes required for the foam in a box mould infused harry, where most of the cuts are straight, and the accuracy of the curved ones is not critical.

    No idea about where the KSS builds are apart from the commercial ones at Ballotta and the guys in Tennessee, but Derek is a friendly and approachable guy. His email is derek at kelsall.com He often posts on multihulls@steam radio and I think has a yahoo chat group.
     
  9. groper
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    groper Senior Member

    I had peel ply on the panels rob, but the flow media still prints through that. So you tear off the peel ply, and then you still need to lightly fill the panel before painting it or you will see a uniform grid pattern printing through from the flow media... Its not a huge print through, many people could look past it, but i couldnt... i felt i needed to get rid of it before final painting and so the prep work before paint is not avoided... if the panels are large, then you still have the overlap in the glass to deal with on the bag side also...

    Not sure why the CNC cost was so high...? i got 100 sheets of foam CNC routed for less than $2000 locally. I provided the cut files for them, dropped off the sheets, and picked them up when done.
     
  10. Barra
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    Barra Junior Member

    Rob , I desperately want to be a believer.

    How many harryproas have you completed and launched with this u-beaut no grinding, no fairing method?

    I would love to see ONE !

    Is it possible to point the non-believers to a completed , sailing, harryproa, constructed using this AMAZING method?

    This no grind/no fair method sounds like a very quick building method, so I'm happy to wait till the end of the week for the next one to be completed.

    The completed boats on your website appear to be a mixture of foam and cedar one offs, constructed in the conventional manner.

    Forever hopeful

    Barra
     
  11. rob denney
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    rob denney Senior Member

    Thick perf plastic might have been enough. For panels needing a smooth surface, we rebate the joins. Deeper rather than shallower and you have a narrow, shallow trench to fill rather than an entire panel. Ditto for any taping that you want to hide.

    Good price. Well worth considering for a conventional build. Less so for the harrys as so much of it is either straight cuts or non critical curves and the cut outs are used to make hatches, doors etc, so the gaps would be too wide.

    Barra.
    None sailing. We only finished figuring it all out in the last few months. When there are some sailing, there will be little or nothing to see that is different to a standard build because the differences are in the cost, weight and mess reductions, the boats look like any others.

    Bucket List https://www.youtube.com/watch?v=ttXu3pRTzs8 was the first on which we used some of the techniques. Future versions will use all of them, which is why we can keep the price down to $50k for a 40'ter ready to sail. There are some prototype build photos and description at http://harryproa.com/?p=424
    There is a Cruiser 60 being professionally built by Ballotta, who have built a lot of KSS cats, so should be good for some comparative feedback.
    A couple of smaller boats are being built locally so I can keep an eye on the technique and a 22' power cat is under way in Canada. This will be the tender for a 70' harry racer/cruiser.
    I have built a lot of samples, including a couple of hulls, and Steinar (harryproa stylist) is using as much as he can on his 20m. http://harryproa.com/?p=726

    The feedback from these builders and others who have seen the plans has been positive. Which is not surprising as there is nothing radical about the techniques. Most of it isn't even new. It is an ongoing evolution of all the things we have been doing since Derek introduced me to infusion ~10 years ago. A lot of small things, not all of which apply to boats generally, but they work a treat on the harry hull shapes.

    If you are ever in this part of the world (Gold Coast), drop in and i will show you what is involved.
     

  12. groper
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    groper Senior Member

    I played around with the trough type molds way back at the start of my build rob, infused the compound curved sections of the lower hulls.

    [​IMG]

    I also mucked around with an idea to infuse a round bilge shape with virtually no mold at all. The pics tell the story;

    [​IMG]

    [​IMG]

    Tho I still don't think the finish is good enough to paint straight out of th bag, there is still print through of just the fibres themselves. Sure you can take it straight to high build, but you still have to do some filling of the fiber weave unless you use a veil cloth on the outside which adds a bit of weight and something I didn't want to do... At the end of the day, unless it comes off a hard mold surface, i still haven't found a solution ...
     
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