Saturday, July 21, 2012

Rebuilding the Second Beam

The 2 by 3 timber that I used to build the second beam were curved and I was not aware of the "proper" way to uncurve the wood.Instead of opposing the curves of the wood I followed the curvature of the timber. The problem comes when I had to place the next two pieces of 2 by 3 timber on top. It was an almost impossible task so I had to consult my good friend Ah Ying who is a master carpenter.


His solution was simple..Tear off the 9 mm  ply on both sides. After tearing off the 9 mm ply I prepared the surface by grinding off the epoxy and planning the 2 by 3 timber again...no not to plane it straight but to plane it so that there is no more epoxy.

Meanwhile I was cutting the stainless 3/8 inch bolts to the correct size. It came in a long rod 7 ft long and I only require 7 inches per bolt.


Ah Ying came today and he helped me to rebuild the beam. I should  have done it this way from the start. Build one "box" first and then join together the second box.Here the first "box" is completed and we were in the process of joining the second box


The trick is to use 1 inch stainless steel nails to "force" straighten the old piece of structure

. .
After that it was drilling holes about 30 inches apart to put in the stainless steel bolts and nuts. This combined with the epoxy will make a super strong beam.


Now both the beams are ready...well almost as some trimming will be required later

Monday, July 9, 2012

Building the Main Beams for my Gypsy catamaran

A catamaran has two identical hulls which are built separately. When the hulls are completed they have to be joined together. To do this two main beams have to be built. The plan calls for using "best quality hardwood" 2 inch by 3 inch to be used. For this special hardwood I was recommended a tropical hardwood BALAU HITAM . This species was recommended to me by a hasher friend and he had been kind enough to select a  matured  tree to saw the timber for me.

The wood is then planned so that the boding with epoxy is better. This is tough work with a hand planner.


The 2 by 3 are laminated with 9 mm ply on the outside and 6 mm ply on the inside.The width of the marine ply is 220 mm. There must be sufficient clamps to get the job done and in boat building there is never sufficient clamps!
Since I do not have sufficient clamps I build the beam in sections of 8 ft. The plywood are joined with a 200 mm ply.
I was hoping that I could save some time by building both the beams together.The first beam on the left came out as predicted with no surprises.

The plan calls for 4 inch screws to be screwed in place at 100 mm apart. I did not like the idea and I propose to use a stainless steel bolt to be bolted through the 2 by 3 s at lesser intervals. This was accepted by the designer Richard Woods.
Now, there is a "little" problem with the second beam on the right. Because of some warping in the timber it became almost impossible to place the other 2 by 3 timber on top.without tearing the plywood. Now, rebuilding the second beam will be another interesting story.


Tuesday, July 3, 2012

My hulls are perfect!


Normally the hulls are covered with cheap canvas that I purchase from the hardware shop. However about 4 ft of both the hulls protrudes outside my canvas shed. This year has has been an exceptionally wet year and when there is a heavy rain with strong wind water leaks into the forward two compartments.

On a bad day water may even flow to the other compartments. I use this to check if my hulls are completely waterproof without any leaks. Both the hulls passed with flying colours!

Then comes the back breaking task of bailing out the water. Too little to set up a pump and too many squats and back bending to scoop out the water!

And when it is almost dry I will have to use a sponge to take the last drops away. The last few drops I usually leave it to the sun to dry it out. If I had left the hulls uncovered when I go flying and it rains, I will have to repeat the  exercise again! Thank god the dry weather period is here again!