Injection Molded Sunfish

Discussion in 'Sunfish Talk' started by Tillerman, Apr 22, 2016.

  1. Charles Howard

    Charles Howard Member

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    If they are lighter then people who race will have to buy new boats. Not good for those of us who just bought a new boat. Not good for the class having so many variations for a one design.
    Does the owner of the Sunfish sail at all?
     
  2. Tillerman

    Tillerman Member

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    Well that's the real issue isn't it?

    Is the Sunfish class going to make sure that Chinese Sunfish and (0ld) American Sunfish are identical for all practical purposes in term of racing performance?

    Or are they going to let LP make Sunfish in China which are lighter and stronger and stiffer (and therefore faster) than (old) American built Sunfish?
     
  3. Sailflow

    Sailflow Member

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    I hope LP is listening to the Sunfish class.

    Sunfish are a low volume product as compared to the 60’s and 70’s. A recreational Sunfish will last 40 years and so will the sail, often passed down in families, so not a lot of repeat volume. There are more recreational then racing sunfish by far.

    Racers on the other hand buy new Sunfish more often as the boat softens. They buy new sails every couple of years, new booms, masts and centerboards as they may get damaged. If you look at the Sunfish Worlds and North American, Sunfish racing is increasing in many countries.

    You think LP would want a boat that meets the racers as they will be repeatedly buying new boats.
     
  4. beldar boathead

    beldar boathead Well-Known Member

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    The class is working on it from what I hear. But oh wise Tillerman can you please enlighten us as to how the class can "make sure" of anything? Can you also provide guidance as to how the class can dictate anything to the mfr??? Not clear on what the class can do to instruct LP as to what to do. As soon as you figure that out, can you instruct them to please ensure a plentiful supply of both Sunfish and Laser blades? Thanks for the help. BB
     
  5. foxy

    foxy Member

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    There are several different ways to put resin into a laminate. With any of the processes, the fabric is laid dry into the mold. With infusion, there is an airtight bag placed inside the laminate and a vacuum is pulled on the bag. Resin is pulled from a reservoir through hoses spaced around the product. The vacuum draws resin through the fabric. When the fabric is saturated, the resin flow is shut off and the resin is allowed to harden. The process works best with cored laminates where the resin can flow through grooves in the core. When you have single skin laminates, you need some kind of carrier layer, or a fabric designed not to compress too much under the vacuum.

    With resin transfer molding, the resin is forced into the fabric by pressure in the reservoir. One pretty much needs a two sided mold and the result is a part with two good surfaces, although it is usually somewhat heavier. Its a good process for small parts that need a good finish on both sides. The molds have to be very strong to withstand the pressure so the process is normally reserved for small parts where there will be a lot of volume in production.

    Vacuum assisted resin transfer molding, VARTIM, is a combination of both and is very likely the system used on the newer Laser foils. The fabric is placed in the mold along with the foam shape in the center of the foil. Then resin is pumped into the mold at one or more points, and a vacuum is pulled from one or more points. This works well for the rudders and daggerboards, but not really well for hulls and decks unless you build two part molds.

    So I suspect that the parts will be made with infusion and that there will be some kind of resin carrier, probably similar to the one used with SCRIMP. If the laminate has less resin, it will be lighter, but also thinner and not as stiff as the open molded boats. Stiffness varies with the 8th power of thickness, so you don't have to loose much laminate thickness to make a lot of difference. The laminate may be stronger when measured in terms of strength per unit such as PSI, but there is less volume of material, so there is no gain in the real world, only is advertising hype.

    Basically,it wouldn't be feasible to build a Sunfish that is lighter, stiffer, and stronger without radically changing the materials that the boat is made from. I think the best you can hope for is an equal product.
     
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  6. Wavedancer

    Wavedancer Upside down? Staff Member

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    P-J Patin, Sunfish Class President, has an update which addresses some of the issues raised in this thread:
    International Sunfish Class Association


    Of course, in the long run, we will just have to see...
     
  7. Gail

    Gail 24186

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    The manufacturer has sent the molds to China. Boats are being built. The intention is for them to remain fiberglass and resin. The rest of it is still very unclear. No, it's damned near impossible to "call LP" and get any reasonable facsimile of conversation. We will have to wait for the information that the International President provides from time to time. On his own dime he has traveled to China to see what they have going so far and found it suitable (or maybe better). We won't really know until there is a fleet of boats and they get sailed. New boats is better than no boats. If they are drastically different, then yes, there will be issues. I've been chiming that they need to be kept the same weight so we don't obsolete 500,000 boats. Also supposed to be able to get a reliable supply of parts again soon. We can only hope.
     
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  8. water rat

    water rat Member

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    Knocking the China products reminds me of how..years ago we made fun of the Japanese stuff. They ended up by kicking our ass . Sure China turns out alot of crap but the smart money in manufacturing is in Medium to top grade stuff and alot of it is sold with American brand names. For instance there are some very well built fiberglass sea kayaks coming out of China and getting good reviews. . The key to quality for American companies manufacuring there is have your own people spread thru out the plant. . Chapter Two. Harbor Freight Trailers. . If you replace the bunk beds with longer ones shaped to the hull and well padded the $320 trailer will do the job. You have to put it together but that's fairly easy. Warning: The grease in the wheels is crap. But a pair of Buddy Bearings on it and pimp them full until you see the stuff coming out a small whole. .When towing make sure you stop every 25 to 50 miles and feel the hubs. If they are cool or just warm you are in good shape but if they burn your hand...drive no further...pump more grease. As for changing the stuff I just pump new grease in until the dirty stuff comes out. I don't suggest it for you but it has worked for me for more than a decade and my RV is built on a HF trailer and has logged nearly 10,000 miles.
     
  9. fhhuber

    fhhuber Member

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    note: tightening the wheel bearings too tight will make them get hot fast.
    Tighten till you can tell the bearings are dragging then loosen 1/8 turn.
    Ensure the wheel spins freely, without being able to wobble it...
    Put the cotter key in the closest slot.
     
  10. water rat

    water rat Member

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    Goof advice. What you don't want is a pair of flaming wheels
     
  11. Sylvan Sunfish

    Sylvan Sunfish New Member

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    [QUOTE="Tillerman, post:



    [/QUOTE]

    Damn them boys work fast
     
  12. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    I dunno. :rolleyes: Demand/Supply would dictate the value of our Sunfishes.

    There seem to be plenty of Sunfish in back yards and garages going for short money (or recently, for free). :confused:

    That would tend to drive up the value of older Sunfish, and make all the labor-intensive efforts of repair—within the USA—even more rewarding. :)
     
  13. Webfoot1

    Webfoot1 Active Member

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    Supply and Demand is what is happening here. Total market demand for a new Sunfish is limited by the final cost to the consumer.
    Than means Racers and a limited number of general up scale consumers will buy a new Sunfish. New Sunfish must compete against
    the vast majority who will buy a older used Sunfish. They are trying to compensate for increased material and labor costs to maintain market
    share using more efficient methods. At some point in the future these fixed costs will drive the price up to the point where Sunfish
    can no longer be manufactured. For now injection moulding will provide more consistent hulls which should help racers. As said above
    there is a minimum amount of material that can be used before strength is an issue. If there is a weight difference it will not be very much. Adding
    a few pounds to a Sunfish would not be difficult such as adding a weighted plug to the bottom of the mast tube. My guess is that since
    Racers are such an important market they will not deviate from a totally class legal boat in any way. China does have quality control problems
    but looking at older Sunfish I'd say the quality varied widely from boat to boat and manufacture. Today's manufacture quality should be far above
    yesterdays processes. All in all racers should come out the winners.
     
  14. Charles Howard

    Charles Howard Member

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    Has anyone seen a new sunfish this year?

    Dealers don't have them. They have missed the summer market in the United States.

    There are no real class parts available.
     
  15. Webfoot1

    Webfoot1 Active Member

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    If it went to China then it would take time to ship all the tooling over and set-up, re source suppliers, train
    workers. Kind of fits in with what's going on. Would make current race-worthy boats much more valuable
    to own. If it take more than 2 seasons to ship in volume a turn-key boat is going to be gold in the pocket.
     
  16. Charles Howard

    Charles Howard Member

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    I believe everything was set up in April.

    Sunfish are not a volume product, not even a 1000 boats a year.
     
  17. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    I raced cars in a new class of racers called "Showroom-Stock". Complaints were eventually raised that some racers were able to "shop" dealers' inventories for the best parts :mad: and "Showroom-Stock" cars got rebuilt drivetrains—with those best parts—before they hit the track. :confused: I did OK, but the class was doomed by $ponsorship$. I readily beat the delightful lady-racer Lyn St. James, (most recently with Ford at Indy 500 and CART), but mostly because she couldn't keep her GM Cosworth-Vega running! :oops:

    If new Sunfish come out of the chocks with totally class-legal boats, racers would already have a head start over the older boats. :cool: That said, selecting the right older boat, and "tweaking" the bottom to limit flex could put the (many available) older boat(s) ahead. :) Including mine! With time, such standardization with new injection-molded hulls certainly ought to settle the question of fine-sanding the hull. :rolleyes:
     
  18. mixmkr

    mixmkr Active Member

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    Ya know...I think you could easily stiffen the hull of a Sunfish, without adding a bunch of weight. Probably could keep it under 5 lbs. Would just take some cutting and ripping the hull apart, but a piece of aluminum L bracket glassed along the hull would do quite a bit. Even some bottom to deck supports as well with foam. Probably isn't legal, but how would anyone ever really know....IF you were dishonest
     
  19. beldar boathead

    beldar boathead Well-Known Member

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    Well if someone feels good about cheating to win they've got other problems.
     
  20. mixmkr

    mixmkr Active Member

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    I agree, they've got other problems. My point was it would be easy to do, but I figure altering the hull isn't class legal. Seeing that there's been plenty of "cheating" in sailboat racing, all the way to the Amers Cup, it wouldn't surprise me if someone did something like that. All kinds of people in this world nowadays.

    But additionally, to someone like me that doesn't really care about Sunfish Class racing as an activity, but wanted to optimize the boat because they enjoy doing it, stiffening the hull is an easy proposition, as I was stating.
     

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