Thursday, August 16, 2018

UK Nationals

Gordon & John - first.
Gordon was Topper World Champion in 1990s
- has bone-on-bone ankle, and other ankle had a fracture.
- sailed a MK II, rigged by his father
- "Keep it flat, feather into the wind."
- luffed Paul to wind when Paul tried to pass him to windward
- crushing boat speed
- hadn't sailed the Kestrel or practiced.
- boat had aluminum stiffening for centerboard and for athwartships between chainplates

Boat Repairs:
 - boat had a 3" x 1" fiberglass crack on the centerline, right at the position where the boat sits on the front trolley support.  (Bouncing while trailering?)
- 2 gallons of water accumulated in the front tank during 2 hours of sailing.  Bow heavy!
- Richard Roberts tried a fix-on-the-spot before launch, taping with blue PVC tape.
The tape shrugged off with water flow, and 2 more gallons in the front tank.
- Thanks to Steve Worf's crew, Dave, and Richard Roberts, we fixed the breach.  1 minute epoxy from B & Q hardware, held in place and shaped smoothly with gorrilla tape for 2 hours.
-After two hours, the gorilla tape was removed, and we sealed it up with "Helicopter Tape."  Officially, it's 3M 8671HS Polyurethane Protective Tape.  A lot of bikers use it to protect cabon fiber chips on bikes, and it's used to protect helicopter carbon fiber blades.
- Guess what!  It also seals a boat hull when a crack occurs through the hull.

Thursday, May 17, 2018

Kestrel Shrouds

The side stays measures 175 1/16" from marine-eye bearing surface to the swaged end of the T-Ball fitting "4", the T-ball fitting "4" measures 2 7/8", for a total length, bearing surface to bearing surface, of 177 15/16".

The chainplate adjusters add 3 3/8" bearing surface to bearing surface.

The total distance for a rake of 23' 4" is the total of the shroud length and chainplate, = 181 5/16"

The forestay, T-ball fitting "4" bearing surface to eye-loop = 200".  The eye on the original Hartley shroud was 11 3/4" long, and often exited right at the deck of the boat, catching on the exit hole on either side, and preventing adustment.  They eye only needs to be large enough to attach to the purchase system for rig tension, with either a shackle or soft shackle.

Tuesday, May 8, 2018

Making Dyneema Shrouds

1. Measure original Hartley shrouds, chainplate and chainplate adjusters.
  (a) chainplate adjusters set at 2 15/16" above to of chainplate
  (b) line up all shrouds
  (c) Hartley shrouds tball to bearing surface = 176 3/8"
  (d) cut dyneema rope to 19 ft each
2 15/16"
long view of measuring on floor line up the shroudsHartley shrouds are 176 3/8"
dyneema shrouds need 19' of rope


2. Attach dyneema to t-ball fittings, and prestretch dymeena, putting it under bearing load of at least 190 pounds.  Dyneema needs braids need to "set"

3.  Stitch the tball loops to secure.

4.  Given the Hartley shrouds are 176 3/8" and chainplates are 2 15/16", the length of the dyneema to the top of chainplate is 179 5/16"

5.  Stitch a colored thread at 24" above chainplate for future mark, at 155 5/16"

Sunday, April 8, 2018

Gel Coat, Scratches and paint damage



If you’ve owned a Kestrel, have you ever spent any time attending to her needs?
A rhetorical question if there ever was one!  Now, smile, and read on, if only you are so inclined about the subject.  This story is limited to painting repair, which is only a small section of the types of work these boats request of their owners.  After several years, I finally am now getting good paint and scuff repair results quickly.  This takes me a weekend.  About one day to prep and paint, with paint drying times, and I sand and buff in a few hours on day #2.
These are notes to myself after just completing the job.


Larry’s steps and rules to repair seasonal scuffs and damages to gel coat:
1.      Inventory what you have on hand.  You need:
       Paint/gel coat, hardener MEK
       Styrene wax additive for final coat of gel coat
       Paint measuring/mixing containers (I use 3 oz disposable)
       Popsicle sticks/stirrers
       Cocktail drink straw – to add drops of MEK hardener.
       Eye-dropper – for adding gel coat hardener by the drop
       Plastic spoons (to transfer small amounts of paint/gel coat into mixing container
       1 “ wide foam brushes
       Sandpaper grits (60, 100, 150, 220, 320)
                                           both in sheets (hand sanding) and Velcro circular pads that attach to electric sander.
       Wet sand sandpaper grits (400, 800, 1000, 1500, 2000)  (hand sanding)
       Water bucket – for wetting wet sand paper
       Griots electric buffer.
       Wool pad to fit the buffer for first buff.  Wool cuts more than foam.
       Foam pad for polishing to fit the buffer.  Griots has a grey pad.  Instead of “cutting,” Griots uses the term “correcting” pad.
       Polish compound for cut & polish (as opposed to “cut only” and “polish only” types)
       Heat lamp (for gel coat curing acceleration)
       Hair dryer (for paint drying acceleration)
2.      BUFF OUT THE LITTLE DINGS AND SCUFFS FIRST
Why buff the little ones first?  We can’t ever help ourselves but to go around the boat with the extra paint and dab away at the little scratches and dings.  Natural instinct – to not waste the leftover (and expensive) paint.  The problem is, it just creates more work, sanding, and so forth.  And so, have fun, and find out how many will go away with simple buffing.

Go directly to step 16 to buff the little dings, and then return here.

3.      Admire how much better she looks, and at how many dings disappeared in about 10 minutes.

4.      Now begin the paint work:
5.      Sand damaged surfacces with the rotary sander, and by hand, the deep marks with 220 grit.
6.      For those damages, chips and deep scratches that need extra work, sand with 150 grit, go to 100 and to 60 grit if necessary.  Remove the damaged paint.
7.      Now work/sand those dings that required the tougher grit progressively backward, from the lowest used, to 220 grit
8.      How deeply do we sand?  The goal is to scuff the surface so that the paint or gel coat adheres to the rougher surface, each little sanded area like mini-velcrow loop and hooks, nooks and crannies that locks, adheres, and hardens fast to the new paint.
9.      Apply the paint, either spray, or with a foam brush.  Remember, paint adds weight.  Go easy, but enough coats to bring a thickness at or above the surrounding good paint thickness.  Don’t worry about the amount of paint, apply coats as needed.  And remember, the fairing process will sand away up to 1/3 to ½ of what you put on.

When I’ve applied paint with a paint brush, the bristles leave a finished product that has brush lines, which require sanding smooth with 120 grit.  This is ok, but extra sanding work.  Rule #1 will assure that you have a foam brush or sprayer, and thus you won’t go running about the house looking for and using a spare paint brush because you forgot to get one.  It wastes your valuable time.

10.   Brush each coat in opposite directions with the foam brush.  Pay attention to the uneven surface left behind after each coat, use your reading glasses if necessary, and follow the paint manufactures directions explicitly.
11.    Cure gelcoat with heat lamps if needed, a little heat up to 100 degrees) speeds gel coat cure time.  If painting, feel free to use a hair dryer on low, but be careful. 
12.    Once you are satisfied with enough coats of paint that you are ready to make it smooth and glossy, start sanding.
13.    The goal is that the entire sanded surface looks the same to the eye, a consistent haze with 150 grit.  If you see single scratches through the rough hazed sanded area, or if you still see brush marks, work it by hand a little.  It does not take long.  If you start to remove paint at the edge of the job area, stop sanding the edges of the new paint with that grit size.  Lower grit will feather the edges of the new paint to the old.  The perfect job leaves a dull, random scuffed, chalky but consistent haze.  Then sand with 220 grit, and with 320 grit.
14.  It will then take only a few swirls of sanding at each progressively finer grit.
15.  Clean the surface.  I’ll be dog-gone, it has scratches!  Guess what?  Now you can go back and redo step 9 -14.  I don’t.  A few scratches are fine with me.  Every boat that races has them.
16.  Wet sanding works very well from 400 grit, to 800, 1000, 1500 and 2000 grit.  Get a bucket of water, keep the surface weight, and move right up the ladder of grit size.  Sand in swirling motions.  It doesn’t take a lot of sanding at each grit.  The combined 10 swirls of each of these wet grits gives 50 total swirls on each spot, and that is enough 
17.   I buff twice with an electric buffer.  You can watch videos on YouTube that explain buffing.  I spent many hours watching and trying to buff, and I never had good results.  The reason is that most of those videos use different products, different equipment, and are shown for those who are detailing autos.  In those videos, the pros do not leave any scratches, use paint booths to apply paint, have all of the proper paint thinners, humidity, temperature and so forth.  We amateurs can’t replicate (or at least this write-up is not so intended) the ultra-fine shine that is produced by professional car detailers.  Don’t feel bad about it.  Those cost $2,000 US - $8,000 US.  Our project is in the hundreds of dollars.  I can live with scratches that can only be seen, and not felt.
18.   My buffing is two-step because it is quick.  I use a wool pad for the first buff.  Wool is a product “cutter” which means that it removes paint.  It does not heat up as much as a foam buff.  Wool is abrasive.  By itself, a wool pad puff might leave a shine that makes you happy.  I use a buffing compound that is designed to “cut” and “polish” with the wool pad.  Some of the compounds have more grit, and will be labeled “cut,” while others have no grit, function as lubricants to smooth the paint from heat generated during friction from buffing.
19.   The “no grit” buffs achieve the finest mirror finish.  I can’t replicate the conditions in my garage to use these fine, high gloss, non-cutting polishing compounds effectively.  I spent a lot of time (many hours) trying to be a perfectionist, and finally concede my time is not worth trying.  It reminds me of trying to sail without a tiller extension.
20.   My second buff is with a foam pad, and I use the same cut/polish compound that I used with the wool pad.
21.   Both buffs don’t require endless buffing.  Move the buffer in circular motions, go over a few times, don’t buff too much, and take a look at the finish.
22.   You will see imperfections in your job.  Don’t sweat it.  You are not a professional.  Your result will not impede your racing results
You can see some scratches, but not an impact on racing, and this photo is enhanced.
They really aren't that bad.  The extra time to do better has diminishing returns, requires a professional shop environment


Tuesday, February 27, 2018

Tuning Notes 11-17-2017

Here are tuning notes from 11/17/2017:

  1. Mast butt-possibly move forward 5mm
  2. Loos gauge @22 for 250 lbs on stainless wire shrouds.
  3. Lower mast marked in red to the center of the tension block.
  4. Shrouds - no play in them; measure with a square to balance left to right angle sweep.
  5. Spreader length - set at 445mm - very heavy crew weight.  Target is 435 for heavy.  Longer is stiffer.
  6. Sweep is 185, vs 190, Nick thinks even stiffer
  7. In hiking conditions, head stay tight!
  8. To tighten head stay, more ram to straighten the mast.
  9. Tight headstay keeps the slot open
  10. Reduce shackle on jib tack - smaller, lower the sail.

Sunday, February 25, 2018

Dyneema under tension with a Loos gauge

I hung dumbbells from the ceiling rafters of my garage with 1/8" dyneema.
I did this with 250lbs, 220lbs, 190lbs, 160lbs, 130lbs.  Below are the pictures showing how this test registered on a Loos Gauge.  I measured 275lbs and 300lbs on 3/16.2018.  Results were consistent in Nov 2017, Jan 2018 and Feb 2018 with different dyneema line:
275 as 50,50,45,45,40,40,5
275# = 21.5

300 as 50,50,45,45,40,40,30
300 lbs @ 22.5