Naval cadet boats

Construction of Jewell began in May 2014.

Planking cont.

July 28, 2014tony o'connor

With the garboards fitted and glassed, the rest of the planks are fitted in the usual manner.

Plank no.2 fitted, the wooden blocks sticking out from the frames are for the plank to rest on while fitting.

Planking continues with each plank sealed and sanded on the inside and each of the scarfs glassed on the inside also.

Fitting fourth plank, the wooden clamp helps to hold the edges together, small screws are also used.

Monday 28th. 4th planks on both sides fitted. Hopefully if I don't have too many distractions for the rest of the week I will be able to get the final planks on by the end of the month.

Final plank, Thursday 31st.

Side view showing wooden plank clamps and supports for the plank.

Now that the final plank is fitted the next job is to fill screw holes, fair planks, fit outer stem, fllet the plank edges to the adjoining plank and then start to undercoat the hull. The plan is to prime and undercoat the hull , then turn the hull over and do the fitting out, the final coat will be applied when the fitout is complete.

Planking 2, garboards.

July 13, 2014tony o'connor

The garboards have a lot of twist forward, and are substantially wider than all the other planks.

I decided to fit them in stages, fitting the forward panel first, and glueing the middle and aft panel together on the bench to attach later.

Forward panels being fitted, a couple of screws with washers attach the planks to the stem in their correct position, the wooden  blocks on the frames hold the planks in place at an angle to avoid twisting the planks while screwing to the stem. — Forward panels being fitted, a couple of screws with washers attach the planks to the stem in their correct position, the wooden blocks on the frames hold the planks in place at an angle to avoid twisting the planks while screwing to the stem.

Planks fixed down in place without the aft ends attached. I also used some screws in the frames to hold the planks in position.

The sole and garboard are attached stitch and  glue style, this is the froward panel being glued in, I used copper wire from a local electrical shop to hold the panels together as well as the clamps and screws. — The sole and garboard are attached stitch and glue style, this is the froward panel being glued in, I used copper wire from a local electrical shop to hold the panels together as well as the clamps and screws.

I forgot to bevel the forward ends before fitting, here is the middle and aft panels already glued together, being bevelled, It is much easier to bevel on the bench than on the boat.

Dry fitting the forward end to the rest of the plank.

The plans call for the sole-garboard to be glassed after planking is completed, but I decided to glass them at this stage as they are more accessible now, this is why I haven't fitted the side shelves yet too.

After the planks are glued in, the joint between them is glassed with a double bias tape, I also glassed the keel sides at the same time, here we are preparing to glass the bottom, the green tape is on  the areas not to be glassed. — After the planks are glued in, the joint between them is glassed with a double bias tape, I also glassed the keel sides at the same time, here we are preparing to glass the bottom, the green tape is on the areas not to be glassed.

!st layer is a 300gram double bias cloth.

First layer wetted out, now the next layer.

Finally the cloth is covered with peelply and a couple of hours later when the resin is at the "green" stage the cloth is trimmed back to its final size.

Planking the hull 1, keel and sole.

July 05, 2014tony o'connor

It is my goal to have this hull planked by the end of July.

Since the planking is already cut on the cnc machine this shouldn't be too difficult except that before I can plank the hull I have to sheath the sole and garboard with two layers of glass cloth...and before I can do that I have to finish the keel.

Fitting sole

The sole is made from two pieces joined just forward of the centerboard case, the elongated slots forward of the joint are for the keel itself, It slots nicely over the centreboard case, I cut a v-groove all around the cutout to allow plenty of glue… — The sole is made from two pieces joined just forward of the centerboard case, the elongated slots forward of the joint are for the keel itself, It slots nicely over the centreboard case, I cut a v-groove all around the cutout to allow plenty of glue around the joint.

Fitting ply doublers either side of the case, these will increase the width allowing room for required amount of ballast and also beef up the case side where the pivot pin will be.

Next is the keel

The keel sides are clamped to the centreboard case and also located with small mortices into slots cut into the sloe. Each end has a "stem" a bevelled piece of wood that the sides are screwed to. The dimensions are in the plans. This piece is t… — The keel sides are clamped to the centreboard case and also located with small mortices into slots cut into the sloe.
Each end has a "stem" a bevelled piece of wood that the sides are screwed to. The dimensions are in the plans. This piece is the first part of the building process that required any shaping with hand tools.

Glueing the keel in place with a small fillet on both sides, a larger fillet will be made later

View from aft and above showing hollow ends, the aft end is filled with high density foam the forward end with 120 kg of lead.

The keel base is solid timber, a pattern for which is in each kit, I haven't cut the sheets with the pattern  in just yet so I just laid the wood in place and drew around it. The glue line in the picture is because I used some old Jarrah I had … — The keel base is solid timber, a pattern for which is in each kit, I haven't cut the sheets with the pattern in just yet so I just laid the wood in place and drew around it. The glue line in the picture is because I used some old Jarrah I had , If you are goung to use Jarrah on any boat then the keel is the place for it because it is very hard and heavy. I don't mind it being glued from two pieces as it will be well sheathed after.

The outside also has "stems" whose dimensions are provided in the plans and which require hand shaping.

Almost finished. Now the ends and base are removed to fit ballast and foam .

The plans call for 120 kg of lead to be inserted into the forward end of the keel, I have several bars of lead of different sizes which I cut and planed to size.

this piece for the front of the keel box

I used a reciprocating saw to cut blocks, and also an electric planer for final shaping

Lead shavings from the plane, these are used to pack around the ballast later, and any leftovers are melted down into a new bar.

As more lead is fitted I use epoxy with glue powder mixed with lead shavings to fill the gaps

As the keel fills I used clamps to prevent the keel from splaying as I pack the shavings and epoxy in

I also need to finish the keel base.

The cutout for the centreboard was finished with a flush cutter in the router, but this will mean that when I epoxy the base the insides will be a bit thinner than the case and will be prone to wear.Therefore I need to make the cutout a little bigger. First I use a radiusing bit in the router but one which rebates the radius a little,

Slot as it was  after being routed flush with inside of centreboard case. — Slot as it was after being routed flush with inside of centreboard case.

Then the plank is turned over and flush cut again with the bearing resting on the edge of the radius, leaving a slot approximately 1mm larger all round and a radius so I can lay sheathing cloth into the edge.

Centreboard and transom.

July 05, 2014tony o'connor

The transom is made from two pieces of 9mm ply, with mortices for frames cut into the inner sheet, these are slightly different sizes but when glued together with their top edges flush they assume the bevel required for the planking.

Both faces to be glued are sealed first, then thickened epoxy is spread on one face and they are clamped together, I used a few small screws to prevent them sliding around while the glue set, also I glued them in the morning so I could keep an eye on the mortices and make sure to clean out any glue that squeezed into them or else they would have been completely blocked with thickened epoxy,

Sealing the face of the inner layer of the transom, the thin slots are mortices for frames and must be kept clear of thickened glue , also visible are cutouts for the motor, boomkin, sculling notch and tiller

Sanding the boomkin hole.The two layers are slightly different sizes which gives a stepped  outer edge which gives the bevel for planking. — Sanding the boomkin hole.
The two layers are slightly different sizes which gives a stepped outer edge which gives the bevel for planking.

Transom  is fitted by locating fore and aft frames into the mortices in the inner layer, these will be filleted later. — Transom is fitted by locating fore and aft frames into the mortices in the inner layer, these will be filleted later.

Centre board case.

After two layers of glass cloth and covered with peelply

The spacers were also sheathed with two layers of cloth and then fixed to one side, but because they are radiused on two inner corners These corners had to be sheathed in-situ.

When the glass had cured the box was finally glued together, Offcuts from the spacers are used to make sure the box sides are parallel while the glue cures.

Centreboard case finished and ready for sealing and fitting.

Setting up frames

June 21, 2014tony o'connor

With the building Jig set up the boat frames can be attached and the boat begins to take shape.

Battens for furniture as well as some doublers are fixed to the frames before assembly.

The frames are fixed to the supports with bolts, in this picture I am gently tickling the bolt in with my hammer.

With the frames in place we then fit the transom centreboard case and longitudinal frames all of which like the frames have been pre coated with two coats of epoxy and sanded

The longitudinals all slot into the frames which stiffen the structure considerably but also confirm that everything is in its correct place

This picture shows one of the shelves in position but not sealed, I put this in to verify the position of the forward frames and also it helps to stiffen the structure but it is not fitted permanently yet as it makes access to the keel more difficul… — This picture shows one of the shelves in position but not sealed, I put this in to verify the position of the forward frames and also it helps to stiffen the structure but it is not fitted permanently yet as it makes access to the keel more difficult. It will be sealed, sanded and fitted before the upper planking is attached but for the moment i want to be able to fit the keel and more importantly the ballast without having to lean over too much

building frame

June 19, 2014tony o'connor

The plans include not only cnc cut parts for the boat parts and building molds but also the building jig itself so from the start all aspects of the construction are linked which helps prevent any errors in construction.

This accuracy did present problems at the beginning.

The plans called for the building jig to be constructed from 15mm structural ply from sheets 2440mm long, but here in Australia our home made ply is 2400 mm long and so I had to hunt around to find some imported structural ply.

I eventually located ply which was imported from Brazil, but whether because of climatic conditions or inaccurate manufacturing the sheets varied in thickness by almost 1mm.

Since the various components slot together with pre cut notches this meant I had to ease some of the notches.

Using a piece of wood that  just fitted into the slot I used a technique called saw cutting to run a fine bladed  saw down the edge of the wood cutting into the edge of the ply — Using a piece of wood that just fitted into the slot I used a technique called saw cutting to run a fine bladed saw down the edge of the wood cutting into the edge of the ply

I used a small test piece of ply for each slot and where necessary I finished off with a rasp.

The building jig consists of two long panels linked by individually shaped crosspieces which fit into slots at each station, these crosspieces will hold the frames.

In this picture I have only fitted three of the crosspieces, the other pieces can be seen to the left, I have done this to leave the rest of the building frame clear to lay the actual frames on so I can coat them with epoxy.

Frames laid out on building jig ready for sealing

The same frames with two coats of epoxy.

This sanding and sealing took a four days and was a little frustrating since I had all the components in front of me and was keen to start assembling but I wanted them to be fully sealed and sanded so they can be finished off when the boat is assembled without having to try to sand in difficult to reach places.

With the frames sealed and finally sanded I can begin assembly.

First the frame supports can be fitted and levelled

Using a string line to level the frame supports.

In the picture below I have bolted frame 8 to its support, I have omitted support 7 behind it and then used a sharpened stick to check my diagonals against support 6, this is to ensure the building frame is square.

Notice that support 6 has six bumps on its top edge to identify it.

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