Sunday, September 30, 2012

Leeboard repair - the "rope trick"

Dry fitting for the "rope trick"
I damaged the leeboard on Cream Cheese last year by driving away from the launch ramp with the board dragging in the gravel.  I discovered my error after about 50 yards, but by that time I had chewed off about 3/4" inch off of the bottom corner of the leading edge.  Later on Grahame Byrnes, designer of the Core Sound series, told me about "the rope trick".  The idea is to glue an epoxy saturated synthetic rope (usually nylon) to the leading edge of the board, thus providing a well shaped but very durable surface.  Here's an example from the Core Sound 20, Dawn Patrol:

Rope on the rudder of the Core Sound 20, Dawn Patrol.
It protects the leading edge of underwater boards

I decided to try the rope trick myself.  First I cut away the damaged wood and fitted the rope.

Fitting the rope
Then I soaked the rope in epoxy and draped fiberglass cloth over it and let it partially cure (8 hours over a cool night).  I made a mistake at this point in the process.  I should have used thickened epoxy to fill the spaces between the rope and the board but I didn't.  As a result, there are air pockets.  Hopefully this won't be a major issue since the boat is dry sailed and all surfaces are thoroughly coated with epoxy.

Fiberglassing rope in place

Then I filled using epoxy thickened with fused silica and microballoons and let it cure.

Filling and smoothing

I made a first pass at sanding and smoothing and filled some more with thickened epoxy.

Final sanding before painting

Saturday, September 22, 2012

Mainsheet for AF3 - third try is a charm

New nylon webbing reef nettles.

I've always resisted getting "yacht" grade hardware for my little plywood boat, but I've learned that sometimes the expensive stuff makes your boat far more seaworthy than the cheap stuff.

For twelve years, I sailed Cream Cheese with the simple mainsheet arrangement shown on the plans.

Then in March, I modified the rig to bring the sheet forward.

We sailed last weekend in gusty conditions (5 to 15 mph) and I was still unsatisfied with the mainsheet.  It suffered from a number of problems:
1. The line was too thin - 1/4" line is not comfortable to hold when it is really windy
2. Mainsheet was tied to a combination block/jam cleat forward.  This holds the mainsheet too firmly.  It was too difficult to release during gusts.
3. The mainsheet gets in the way when you are coming about.
4. Running the mainsheet through a block on the base of tiller creates an awkward weather helm.

So I looked at the mizzen for the Core Sound 20, which has about the same sail area and the same position in the stern.

Core Sound 20 mizzen sheet

It has three important features:
1. 3/8" line.  Easier to handle in strong winds, lays better in the cockpit.
2. Standup blocks on either side of the tiller - no extra forces on the tiller.
3. Cam cleats - super easy to set or release.  Much safer in gusts.

So I went to and bought some expensive hardware and 50' of low stretch line.
I tried out the new mainsheet arrangement today with more gusty winds.  Wow- what a difference.  Even Julie, who is doesn't usually like sailing in gusts, was very comfortable at the helm.

New main sheet - I'll fix that twist later.

Saturday, September 15, 2012

How to Install a Sailrite Jiffy Grommet

New jiffy grommet, old sail

Before installing the jiffy grommets on my clew and tack reef patches I looked for online tutorials or technical notes but didn't find much, so I'm posting my experience here.

When I got my jiffy grommet kit, there were no instructions other than what is printed on sairite's website "... Special tools are not required - simply use a hammer to mushroom the ends of the soft aluminum rivets in place ..."  After some experimentation, here's the process I decided to use.

I had to push the six rivets through seven layers of 4oz dacron.  I experimented on a test patch with a 1/8" drill, but I found that a 1/8" hole punch was far superior.

1/8" hole punch
After punching the holes, I assembled the grommet.

That jagged circle you see in the luff tape is where an old spur grommet used to be before the reef patch was sewn in place.

Rivets ready to be hammered down
Once I hammered down the rivet, used a soldering iron with a flattened soldering tip to cut the hole through seven layers of fabric.  This was quick and easy and had the added benefit of welding all seven layers together for added strength.

Cutting out the fabric - flattened soldering iron tip on right

Jiffy grommet, sail, tools

Third Reef Pictures

Here's a look at the third reef under sail.  I haven't been out in wind strong enough to know whether there will be significant lee helm.

Pretty Day at Marsh Creek Lake
Sharpie spritsail and clouds 

Sunday, September 9, 2012

Sewing a third reef

I decided to make a third reef for Cream Cheese in May.  It has been 12 years since I sewed the sail, and I wasn't looking forward to re-learning all of the special sail sewing techniques. 

Pretty stitches on the new clew reef patch
As it turned out, it was a fun project.  The first step was to pull out my copy of "Sailmaker's Apprentice," by Emiliano Marino, and re-read a few relevant chapters.  Then I ordered the cloth and jiffy grommets from Sailrite.

Next, I spread the sail out on the floor to plan the location and size the various panels that would be sewn together to make the reef patches.

Reef plan
 I did this by taking off the dimensions from the existing patches.

Reef patch dimensions
At this point I was ready to cut the panels.  My reading indicated that scissors aren't the best for cutting dacron sail material because the cut is more likely to fray under heavy use.  A hot knife is the preferred method, but I wasn't going to fork out $400 for an industrial hot knife.  I settled for attaching a rope cutting blade to my soldering iron (with a little modification).  The edges were a little rough, but it was good enough.

Cutting out dacron panels
I had to redo all of the cringle patches because I got the weave orientation wrong (see "Sailmaker's Apprentice").  Each reef cringle patch is 4" square.  There are two patches for each reef patch and the fabric weave should match the weave of the sail at the point of attachment.

I used basting tape to assemble the clew, tack and cringle patches and then put them aside.

Now I was ready to start sewing, but before I could do that, I needed to freshen up on my sewing skills and make sure the needle, thread and machine were going to be able to go through seven layers of dacron.  This probably took more time than any other part of of the project.  My sewing machine is a Janome 7330, which is a "home decor" machine.  It comes with a two kinds of zig-zag stitches, has a pretty good motor and a fairly strong feeder.  I discovered that this machine with a #90 needle will do a zigzag seam on five layers of 4oz dacron, but not on seven layers.  It works fine with a #110 needle but but I was worried that the holes in the fabric were a little too large.  After talking it over with a few people, I decided to go with the #110 needle and larger holes.  I've been happy with the results.

Janome 7330, basted reef patches, practice patch.
Now I was ready to sew!  This part of the operation went relatively quickly.  First, I cut loose the luff tape (seam along the luff of the sail) and pinned the pre-assembled reef patch to the sail.  Then I rolled up the excess material and started sewing.

First seams going together.
Once the tack and clew patches were sewn on, I pinned and sewed each reef patch.

Reef cringle patch
Now that all patches were on the sail, the last step was to install grommets.  The reef grommets were the easiest.  Simply, cut the hole with a 3/8" hole punch and install the #2 grommet with the two part die set.

Reef cringle patch and tools
Installing the sailrite jiffy grommets on the clew and tack were a bit trickier.  A jiffy grommet is comprised of two washers that are attached to the sail using six aluminum rivets.  The kit came with no instructions and there is very little on the web about the best way to do it, but I'm pleased with the results.  

Third reef  - project complete
Now the third reef is finished - I can hardly wait to try it out in heavy weather.