Showing posts with label ballast. Show all posts
Showing posts with label ballast. Show all posts

Wednesday, July 17, 2019

Paint, centerboard and rudder

Once again, nail setting, puttying and sanding was followed by two epoxy coats on the decking. Three coats of white topside enamel later, the boat is gleaming and bright. I used a little paintable caulk to fill the edges of the decking purely for cosmetic reasons (the joints are solidly glued withe epoxy compound so no leaks are possible). I will need to sand the puttied holes and touch up the sheer strake paint on the outside.

For the centerboard and the rudder I calculated I needed about 6 kg (13.2 lbs) of lead weighting. I opted for lead shot which will be sandwiched between the two outer layers of each, placed in voids cut in the middle layer: a square of 30 cm a side for the CB (for 4.5 kg) and a 8.5 cm radius circle for the rudder (for 1.5 kg). The third photo shows the CB void packed with lead. In calculating the sizes I reckoned on a specific gravity of 11 for lead and a packing ratio of 78% for the little spheres (i.e. the voids between the little balls of lead will be about 22% of the space). I was a bit off and I had a little lead left over.

The fourth photo shows the top layer of the CB laid on with nails  and epoxy and weighed down with stones and a bag of cement. Nothing but the latest technology!

The last photo shows the two main parts of the rudder laminated from three layers. One of them is the pivoting bottom with its own lead ballast inside. I will need to put on the jaws and make a tiller. Both rudder and CB will be shaped hydrodynamically and finished with epoxy and varnish. More in the next post,



Sunday, April 22, 2012

All but the running rigging (almost)

In the last few days, I started by filling the ballast box with lead shot, 50 lbs of it.  I used silicone caulk and styrofoam to seal it into its two compartments (see first photo: forward compartment after the styrofoam went on, aft one before).  I will be screwing the middle floor plank on top.  Then I finished assembling the floor.  It was quite tricky because I had to do everything upside-down, since the cross pieces were glued and screwed on the underside.  Of course in a home-designed and hand-built boat nothing is exactly square and even, so I had to do some sanding, trimming and dealing with inevitable small mistakes after assembly to make all three parts of the floor fit properly.  In doing some of that I managed to cut my left thumb with a detail saw that slipped; not deep enough to need stitches but it took some work to stop the bleeding.  It was the first (and hopefully last) mishap I've had that needed as much as a band-aid.  Anyway, a good reminder to always be careful.  I also drilled ten 7/8-inch holes in all in the floor assemblies, two (one port, one starboard) for each space between frames.  The holes are for pumping the bilges dry, extra ventilation and for my fingers so I can pull the floor up as needed.

Then I reinforced the bow from the inside with two strips of 3/8-inch plywood, and drilled the holes for the U-bolt that will hook to the winch. Then I sanded tops and insides and laid on the first coat of varnish, followed by the second.  Then I gave three coats of white paint to the fore- and side-decks.

I also gave the floor assemblies a coat of epoxy.  They will be varnished next week, mixed with some non-skid grit additive to reduce slipping.  This plus a few other things (like touching up the blue hull paint below the rubrails, locker door closures, installing the three inspection ports with white caulk and screws, and screwing on the middle plank) account for the "almost" part in the title.

Then, on Sunday, on the first anniversary of beginning the physical boat building (the planning of course went on a lot longer than that), I and some friends transferred the boat from its cradle to its new trailer.  Thanks, Gregg, Mark and Ralph! (second photo). 

The last two photos are of the (almost) finished boat (minus the running rigging).   Isn't Aerie a beauty?

In the next 2-3 of weeks I hope to have everything ready for launch, barring any unforeseen issues.  So keep checking 176inches.

boatbuilder