Friday, August 24, 2012

Rudder attachment

I fabricated the rudder cassette this week.  For those who are not familiar, the cassette allows the use of a simple rudder foil which is inserted into from the top.  This allows the sailor to raise the rudder in shallower water and still have some steering.  It also makes it easy to remove the rudder foil when pulling the boat onto a trailer.

I fabricated the cassette using the rudder foil as a mold.  The first step was to wrap the finished rudder in 6 mill plastic with a couple of wraps to provide decent clearance between the cassette and the foil.  I then used the same CF sleeving that I used to create the rudder foil for the inside and outside layers of the cassette, with layers of uni-directional carbon fiber in the middle layers.  Once the epoxy set, I then glued on some "stand-offs" to hold some G10 (fiberglass) tubing in front of the leading edge of the rudder cassette.  The tubing has a 3/8" inside diameter and is intended to hold the stainless steel pin.  Once the epoxy was dry, I faired the area around the tube to insure a nice smooth finish and then wrapped 4" wide unidirectional strips of CF around the G10 tube.  One point is that I used a single length of tubing along the leading edge of the cassette so that I didn't have to worry about aligning different sections of tube.  I later cut off the tube sections that I didn't want.  The picture above shows the cassette before I trimmed it to length.  It also shows the "handle" which will attache to the tiller.  The handle was fabricated using a piece of ordinary pink insulating foam from Home Depot.  I turned the foam on a lathe to get the shape that I wanted (a slight taper from back to front).  I then wrapped the foam with release cloth, then layers of CF (sleeves and uni) and then wrapped that in release cloth.  Once everything hardened, I removed most of the foam using a 1" hole spade (flat drill bit).  Using some needle-nosed pliers I took out the inside layer of release cloth, by just grabbing a corner of the cloth and twisting.  After taking off the outside layer of release cloth and then cutting a U-shaped channel in the handle, I then epoxied it onto the cassette.  I did drill a hole from the top of the handle to allow the rudder pin to be inserted from the top.

 The picture to the right shows the cassette mounted to the stern of the boat with the handle attached to four heavy duty gudgeons (the stainless steel straps which hold the rudder pins) from Racelite hardware.
There have been some broken rudders on some of the earlier i550 boats.  Some of these failures were due to the rudder attachment points bending.  With the four gudgeons and a single 3/8" stainless steel pin, I'm confident that these won't be a point of failure (hopefully the cassette or the rudder foil itself are up to the task)

Friday, August 17, 2012

The mast is vertical - or it was earlier today

 I hoisted the mast for the first time today.  The goal today and the big task was to cut the shrouds to the proper length and then connect the sta-lok terminals that I'm using to connect the stays to the boat.  I used 3/8" line as temporary shrouds and head stay to hoist the mast.  I then measured and cut to length the real head stay and each of the shrouds, and then connected them to the Sta-Master calibrated turnbuckles that I'm using.

One of the best tips that I received at one time or another on one of the forums was to use a Dremel tool with a cut-off wheel to cut the shrouds.  This was so much easier than trying to cut these things with a hack-saw.

Like every other task on the boat, I got pretty good at measuring, cutting, and attaching the sta-lok terminals just as I wrapped up the last one.

Here are the Sta-loks connected to the Sta-Masters.  I used Sta-Master turnbuckles because I've had good luck with them for (many years) on our e-scow.

Monday, August 13, 2012

Foils finally finished

Both the rudder foil and the keel are now finished after applying three coats of primer, a bunch a fairing material and four coats of Interlux Perfection paint.

I couldn't be happier with the way these came out.  The only things left to do are:

  • Fasten a stainless steel plate on the top of the keel.  This will be done with the "Ikea" technique of drilling holes horizontally through the keel which will hold a nut and washer and then drilling down from the top for the bolt which holds on the top plate.
  • I'm going to fabricate a handle for the top of the rudder out of cedar and mahogany.  I left a 1-1/2" carbon fiber tab on top of the rudder to hold the handle.
  • I still need to mold the rudder cassette.  Now that the rudder is finished, I can use it as the mold for the cassette. 

Sunday, August 5, 2012

A ton of small projects need to be completed to finish this boat

 In the past few couple of weeks I've been working on several different projects tying to get the boat done.  The three main categories of work have been on 1) the keel and rudder foil, 2) Standing rigging, and 3) deck hardware.  Items 2 and 3 are a bit of a hold-up because I'm still waiting for delivery of many of the parts that I've ordered.   Here are a few of the activities:

I attached the gooseneck fitting to the mast using pop rivets.
The spreader collars were glued onto the mast using West System G-Flex epoxy.  I used the West system Aluminum prep kit prior to gluing the collars.  The spreaders aren't shown in these pictures, but I trimmed the length of the upper spreaders from 36" to 30".  They just didn't look right.

I riveted on backing plates onto the mast for six shrouds.  I'm waiting for the backing plate for the head-stay to come in.

And finally, I've put a lot of work into fairing, priming and sanding the the rudder foil.  The picture below shows the keel with it's first coat of Interlux Perfection paint.