Rudder head construction

Here's the construction sequence for the rudder head.  I had a couple goals I was trying to meet.  I wanted to line the uphaul/downhaul line channels with copper pipe to reduce friction, and wanted to laminate the center section first to make it easy to clean up and finish areas that will be hard to get at later when fully assembled

I fussed around with the layout for the line channels for a while before deciding on the route shown below.  I wanted the openings to exit the front of the rudder head as near the tiller as possible, and I wanted the rear exit to be gentle, so the line would not need to take a right-angle turn there.  Using the flexible copper pipe, here's what I decided on.

Heres' the exit on the front of the rudder head

And here's the back side.  Because of the thickness of my rudder, I added one layer of 4mm ply in the center of the lamination.

 Here's the glue-up of just the center layers of the rudder head

After the epoxy cured it was time to clean up the edges and trim the tubes to length.

A small hacksaw made quick work of the protruding tubes

And a bit of sanding smooths them down nicely.  I will further round the edges before running the uphaul/downhaul lines over them.

I used epoxy/graphite mixture to match what I did on the cheek pieces

And then laminated the complete assembly.

A Hole in the Boat!

It was time to install the fill hole/drain in the water ballast tank, so I took drill in hand, took a deep breath and drilled a hole in the bottom of the boat!

I had cut out the backing plate from 6mm ply, and then put it in the lathe to turn a recess to inset the fitting so it will end up just shy of the outside of the hull.

I drilled pilot holes for the screws, smeared everything up with thickened epoxy and put it all in place.  I installed the three screws through the epoxy blobs and snugged them down.  Then wiped up the excess and and left it to cure overnight.

Here is the result after scraping things smooth with a utility knife blade.

Next I coated the water ballast tank with graphite.  I'm hoping this will provide a slick, durable surface so that the tank is easy to clean out when needed.

I modified the drain plug by drilling a hole through it and inserting a short length of brass rod.  I then flattened the ends of the rod so that it can't slip out.

And here is the final result ready to go.  The rod on the plug makes it easy to install and remove.

Graphite pinholes, centerboard fairing and weights

I had noticed as I had been coating the inside of the centerboard case parts with epoxy thickened with graphite that there were some places that weren't taking the epoxy.  I don't know why that happened.  I thought they would fill on subsequent coats, but they didn't.  

Probably not a big deal, but I wanted a smooth surface in these areas that would be inaccessible once assembled.

I sanded the shine off to make the spots more visible, mixed up some epoxy/microballoon fairing mix, and filled in the little holes.  Hopefully the filler will adhere OK and will give a smooth appearance when I add the next coat.

Tonight I also finished up the fairing work on the centerboard and rudder pieces.  I used a homemade longboard as well as the random orbit sander.  These pieces are now ready to be covered with fiberglass after the halves are glued together.

And to get another step closer to that, I glued the weights in the centerboard.

Rudder weights glued in

Tonight the various pieces I had epoxied last evening were not cured enough to sand.  I did a little hand sanding on one side of the centerboard, but needs to cure further.  Since the fairing work on the rudder halves is about done I decided it was time to epoxy in the weights, so I did that with some thickened epoxy. 

And then I did another coat of epoxy/graphite  on the two pieces that make up the centerboard case.  I coated over what I had done last night without sanding.  I think since the previous coat is not fully cured that I'll get good adhesion.

This is as much as I will have time for before Jan 1.  Happy New Year!

Graphite coating

Since last update it's been more sanding and epoxy work, and there are no compelling photos from that, but here's a shot showing the second coat on the interior surface of three of the hull panels.

I had a little epoxy left over, so I experimented with mixing graphite in, and applied another coat to the inside of the centerboard case side.  I found the mixture rolled on just fine, though I will need at least one more coat to finish filling the weave of the cloth.

I understand that the graphite/epoxy mixture cures to a very hard and abrasion resistant finish. And that's just what is needed on the inside of the centerboard case where the board swings up and may contact the sides of the case.  I'll use this same mixture on the other side of the centerboard case, as well as on the centerboard itself.

For this job I used some vintage graphite a neighbor gave me about 20 years ago.  The text on the container says this is grade 402A, which is 'ground to an impalpable fineness'.