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Thread: Getting Ready for SHTP 2021

  1. #311
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    Nice job on the canoe! Very nice!

    And I'm right there with Stephen....totally jealous!
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  2. #312
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    It's time to build the brackets on the main rudder, for the trim tab. The stoutest example of this construction that I could find online actually is in bronze, which might be of interest to a few of us...

    This incredibly complex document discusses in great detail, the design of a trim tab system...

    http://www.svsarana.com/selfsteering...trim%20tab.pdf

    If you want even more from them, visit here: http://www.svsarana.com/selfsteering.php

    Their blog, if I remember correctly, has photographs of their outrageously strong...and outrageously heavy trim tab system on their double-ender.

    Anyway, so I've been back and forth, what to do, what to do about the brackets. Use stainless steel straps, which can be unbolted so the whole thing can come off, or epoxy sturdy oak brackets to the rudder to hold the trim tab? Stainless steel underwater really needs zincs on it to stay in one piece. Stainless is also heavy, and the rudder and trim tab itself are already pretty heavy. In the end, I'm opting for oak and epoxy, with some starboard UHMWP bolted in with stainless at the bottom for a bearing surface and an intermediate bracket near the waterline, also with some UHMWP around the shaft for support. The upper two brackets will also be oak, with the McMaster Carr pillow bearings bolted on. If those disintigrate, I'll replace them with UHMWP.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  3. #313
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    Two things contrbuted to me deciding to 'glass the brackets to the rudder, rather than bolt them. 1.) I could make all the brackets-strut and so on out of $14 worth of 4 inch wide, 1" oak, rather than $30 worth of stainless steel. I'm facing some pushback at home over the SHTP ongoing expense.... and 2.) Alan Steel was closed on Wednesday, when I went over to get the stainless. Instead of getting nowhere all weekend, I opted to make the stuff out of wood and epoxy, UHMWPE and glass fiber.

    First up, cutting out and gluing up the upper trim tab rod bracket, and also the strut at the bottom of the rudder that takes the weight of the trim tab.

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    While I was at it, I trimmed down the tiller for the Piper to the appropriate thickness.
    Here's the upper trim tab shaft bracket. It will get a strap of 1" glass tape all round the outside edge. That's probably overkill, but hey. It's a little clunky-looking, I might put it on the saw again and make it a touch more svelte. it will only take side-to-side loads of probably 40-60 pounds, at most.

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    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  4. #314
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    After cutting everything out, smoothing down the epoxy/sawdust spooge with a wood rasp and a bunch of sanding, the bracket tapped nicely into place. Yet more sanding on the rudder will be needed to get a good bonding surface for the glass tape. There's a pillow bearing that goes above the hole that the trim tab shaft goes through. The shaft goes through that bearing, it's pretty low friction.

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    Here's the lower strut, the piece that actually supports the weight of the trim-tab, which is probably about 10 pounds. It's oak, it will get wrapped in fiberglass. Where the trim tab shaft goes has now been cut back and the last thing I did today was make an UHMWPE "bearing" that goes right there, screwed to the oak with four s.s. wood screws. There's been some water intrusion into the rudder from cracks in the bottom fiberglass, so when I trimmed off the bottom inch, there was some drying-out to do. The doug fir core was fine, just needs a day or two or three to dry out. Three lag bolts attach the strut into the bottom of the rudder, as well as a bunch of fiberglass holding all this in place.

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    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  5. #315
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    After much staring and debating...where to put the middle support bracket, I finally opted for a location which might get wet, but will more properly support the trim tab shaft....it's more in the middle. We'll see how the aluminum and bronze pillow bearing does, down there. I'll keep it oiled.

    Anyway, the two upper brackets are glassed on, as of today. I sanded off the paint, down to bare glass and used epoxy/sawdust to make a fillet. 1.5-inch tape went over that. The top of the antifouling paint is well above the waterline. The waterline is actually right where the top of the trim tab is. You can still see a hint of the line, in what's left of the antifouling paint on the rudder.

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    Looks like I got it pretty straight! The red thing is our patio umbrella, fresh out of the spin cycle on the washing machine.

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    Now there's more sanding to do, and then paint. Then I mount the shaft bearings. THEN I slather epoxy all over the endgrain at the bottom of the rudder and take the strut off and wrap it with fiberglass. Once everything kicks off, I crank down on the bolts holding the strut to the bottom of the rudder. It needs to dry out for a few days. Then I make up epoxy and sawdust spooge and shape it....put a layer of 'glass over the whole thing...wait....apply antifouling and call it good.

    Oh, I need to do some microballoons/epoxy and sanding to the trailing edge of the trimtab, itself.

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    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  6. #316
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    The new-to-me J-70 asymmetric spinnaker has arrived, so I set up the end of the pole with some wood to distribute the load and an eye bolt. I hoisted the sail in my slip, today,as there was essentially no wind.

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    I don't know much about assy's, but it seems to me like this is a little bit long on the luff/leech.

    Views of the pole...

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    There's no way to get the outboard end of the pole on the centerline. The bow pulpit won't let it happen.

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    Pole is about 45% extended, 55% on deck.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  7. #317
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    I'd sure like some comments from folks here who know about asymmetrical spinnakers! That's a J-70 spinnaker.

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    forestay length is 27.8 feet
    J = 7.7 feet

    By doing a little math and measuring the pictures on my screen, I come up with a masthead-to-stem distance of 30.8 feet.
    The S2 7.9 has a headstay length of 32 feet...so the S2 has a significantly taller hoist than the J-70 by a foot and a bit.

    The J-70 has a J of 7.7 feet
    The S2 7.9 has a J of 9.5 feet

    Add in the extended length of the J-70's pole and that makes the "spinnaker J" of about 12.4 feet.

    I'm guessing that the sprit I have on the Wildcat, as set up in the picture is about 16 inches past the stem...1.3 feet. So that makes the "spinnaker J" about 10.8 feet. Now, I have the sprit set up on that jury rig with the 2 x 4's. The permanent setup will pretty surely give me at least another 6 inches, maybe 8 inches of extension. So my "actual" working spinnaker J will be about 11.5 feet.

    That's a 10 inch difference in J-length

    So the S2 will have a shorter "spinnaker J", 11.5 feet vs. 12.4 feet ...about 10 inches shorter
    but a slightly longer hoist 32 feet vs. 30.8 feet than the J-70.

    Wind was VERY light in the marina when I set up the spinnaker for that shot...just barely enough to fill the chute. It was trimmed to a point pretty far back in the boat, probably close to where a J-70 trimming point would be. It was trimmed in to somewhere between close reaching and broad reaching for the picture.

    So....dock talk at the marina was that the leech was tighter than the luff, and admittedly, when I pulled the leech down about a foot, the sail seemed to look better. However, I was doing the pulling, which didn't give me a very good view of the sail. QUESTION.

    Does this sail need a recut to make the luff a bit shorter?
    Last edited by AlanH; 12-01-2020 at 12:22 PM.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  8. #318
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    You asked, so three comments:

    A couple times I forgot to extend Ragtime!'s 5.5' sprit and the kite still flew okay, so exact measurements, angles etc. aren't essential. That said . . .

    Most asymms work fine on a reach but to go downwind you need as much separation as possible between the main and spinnaker = a longer sprit. This can be expensive on your rating. I'd temporarily rig up a "sprit" so you can try it at different extensions. Maybe borrow a long spinnaker pole instead and strap it down on the foredeck, but so you can move it. Go sailing and see how much extension you'll need to keep the spinny full at 130 AWA in light-moderate wind and 140-150 in heavier air. Then see what that JSP will do to your boat's rating. This will cost some money, either for Jim Antrim to run the numbers or for a test submittal. (I think if you're a YRA member, rating changes are free.)

    Based on the photo above, I would not shorten the luff - it looks good. In fact, to go downwind I estimate you'd need to ease the tack line at least 12-18" from where you have it tied to the sprit (the tack line needs to go through a block and back to the cockpit.) The long luff, when rotated to windward by easing the tack line and sheet, is what enables you to sail deeper downwind. Some early A2's would even drag in the water because their luffs were so long. Then the trend went to a boxier shape with rounder shoulders - remember that photo of Ragtime! with her newest A2, going into Half Moon Bay?
    .
    Last edited by BobJ; 12-01-2020 at 12:55 PM.

  9. #319
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    by doing a little measuring and math I come up with a "hounds to sprit" length of about 33 feet. for my S2 7.9.
    Doing some measuring and calculations for the J-70 with the sprit extended also comes up with a "hounds to sprit" length of about 33 feet.

    This has got to be awfully close.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  10. #320
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    Quote Originally Posted by BobJ View Post
    You asked, so three comments:

    A couple times I forgot to extend Ragtime!'s 5.5' sprit and the kite still flew okay, so exact measurements, angles etc. aren't essential. That said . . .

    Most asymms work fine on a reach but to go downwind you need as much separation as possible between the main and spinnaker = a longer sprit. This can be expensive on your rating. I'd temporarily rig up a "sprit" so you can try it at different extensions. Maybe borrow a long spinnaker pole instead and strap it down on the foredeck, but so you can move it. Go sailing and see how much extension you'll need to keep the spinny full at 130 AWA in light-moderate wind and 140-150 in heavier air. Then see what that JSP will do to your boat's rating. This will cost some money, either for Jim A. to run the numbers or for a test submittal. (I think if you're a YRA member, rating changes are free.)

    Based on the photo above, I would not shorten the luff - it looks good. The long luff, when rotated to windward by easing the sheet, is what enables you to sail deeper downwind. Some early A2's would drag in the water because their luffs were so long. Then the trend went to a boxier shape with rounder shoulders.
    Thanks, Bob!

    My gut feeling was that this was pretty close, which is why I bought it. Good to know that a few inches here and there will not make a heee-uge difference. I have the carbon pole...that's what I have, so I'm limited by that. Since the pole is only 5' 9", sticking with the 55%/45% ratio, that gives me at most, 31 inches of extension past whatever bracing point I can rig up. Maybe I can get 2 feet out past the forestay? Hardly very racy.

    I bought this for one reason....Days 5-10 of the SHTP. Well, that and the fact that Greg parted with the pole for a ridiculously bargain price, I've never actually played with an asym before, and I'm up for learning about something new.

    OK, no cutting down of spinnakers without more testing! THANK YOU.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

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