Interior Joinery Continued

The salon is finished in the shell - basically. The rest are painters and parquet recliner, but not this year.

Interior Joinery

Meanwhile it is to cold for working with epoxy outside the hull. Therefore I will focus on interior joinery until spring. Due to a tarp over the hull, it is possible to warm up the interior about 10 °C above ambient temperature with 1 kW heating power.
Two weeks ago I started the work on the V-berths in the bow section.

To capture the irregular hull contour I tinkered first a template out of cardboard.

Then I transferred the template on the plywood.

After a few minor adaptation work the bench locker cover fits.

Scoop Edge Planed and Sanded

	Polished cut image of the scoop edge. In the middle of the Picture one can see the upper tangent stringer with the plywood doubler in-between the softwood filling.

Polished cut image of the scoop edge.
In the middle of the Picture one can see the upper tangent stringer with the plywood doubler in-between the softwood filling.

Scoop Completed

I filled the space between the stringers with various softwood residues.

Then the surface was sanded ... 

 ... and coated by plywood afterwards.

  

Working time been invested: 1291 hours 

Keel Fillet

The Dudlex Dix design requires to reinforce the 12 mm thick backbone with 300 g/m² fibreglass fabric over an epoxy fillet on the inside of the hull.
I decided to make my TRÄHOLM  more robust. The thickness of TRÄHOLM's backbone is 20 mm and the fillet is covered with two layers 187 g/m² fibreglass fabric.

 

 

Keel Construction Detail

The hull has been coated with biaxial fibreglass of 600 g/m² weight. Steerboard and portside  coating overlap the keel by about 10 cm. Additionally the keel has been coated with one layer 187 g/m² fabric of 150 mm width and an additional layer 187 g/m² fabric of 75 mm width. Inside of the hull the keel-backbone has been reinforced with an high density epoxy fillet and two layers 187 g/m² fabric.

Satellite View of my Boat

Obviously, the "Google Satellite" flew over my greenhouse ships-yard shortly after turning the hull and has documented the new situation.

Keel Foil Slot

I covered the keel foil slot for the sake of simplicity during glass coating of the hull. Now I reopened it. For this task it was quite convenient that the hull can easily be tilt.

Water In The Boat

Not the boat but the greenhouse roof is leaking. I have scooped about an half liter of water and stretched a tarp over the boat until the roof is repaired.

Successfully Turned Hull

The somewhat expensive preparation has paid off. The turning of the hull was done in 10 minutes and no one came up a sweat. 

Preparations For Turning Over The Hull Finished

I was doing some remaining work on the hull turning device. This Friday it will show whether the device is strong and stiff enough for the task.

Preparations For Turning Over The Hull

Today I finished the aft-side turning wheel. The bow-side wheel is already in progress and will be finished this weekend (hopefully).

Glass Coating

As already mentioned the hull is coated by stitched biaxial fibreglass of 600 g/m² weight.

These non-crimp fabric combine two layers of unidirectional fibres ±45° which are stitched together using a light thread. The result is an engineered biaxial fabric with predictable, repeatable properties.

The pre-cut fabric is spread on the surface prewetted with epoxy. One must be very careful to avoid fiber breakage.



After the fabric is laid-out, it is impregnated with epoxy. About 0.7 kg/m² epoxy is required.

The epoxy is spread by using a "Fliesengummi" (Tilers use it for grouting their tiles)



Finally comes a layer peel-ply (Release Fabric) on the fresh FRP layer. Peel-ply, is a tough, finely woven nylon fabric treated with a release agent.  It is  used to protect the lay-up from contamination. Another advantage: It is no sanding for next layer required.

Right: naked epoxidized fibreglass
Left: epoxidized fibreglass covered by peel-ply

Preparing Glass Coating

The epoxy impregnation of the hull has been finished and I already started sanding the surface to prepare the glass coating.

 

The hull is coated by stitched biaxial fibreglass +/-45°, 600 g/m².
The designer Dudley Dix requires just 450 g/m² at mast step area as shown in sketch bellow. But I think a stiffer hull and harder surface is worth the higher effort.

Preparation For Turning The Hull

 

Turning over the hull I want to accomplish by using two large rings built around the hull.

 

 

 

Each ring is built from three segments of plywood. The ring segments are cold molded from three layer of 6mm plywood strips with 150 mm width.

The Planking Of The Hull Has Been Finished

A first part of the hull has already been impregnated by epoxy.
About 175 g/m² is required for this task. For the hull area of 26 m² I will need about 5 kg epoxi.

 

 

Working time been invested: 1103 hours 

2nd Radius Layer On Starbord Side In Progress

Planking The 2nd Radius Layer

12 Steps for Planking A Radius Segment

Planking the radius segments is more difficult than expected. I thought the bow radius segments should be the most difficult ones because of their small radii. But it turned out that the midships segments were the most challenging. But by use of sufficient force and plenty of screws I have been mastered the task.

Reasons for my trouble:

1. I wanted planking the radius segments between two bulkheads with a single sheet of ply.
2. I wanted scarfing the segment joints.

Most other self builders make it easier. They planking the radius segments with narrow ply strips of about 30 cm width and do it without scarfed joints.

But now in retrospect I would do it my way again if I would build another ship.

  




Bulkhead and Stringers are prepared for planking.

The radius section to be planked is covered by a piece of plywood of sufficient area and temporary fixed by 3x16 mm screws. Then the positions of bulkheads and stringers are marked from inside the hull to the ply.

After the piece of plywood has been removed again, the surplus for the scarfing joint, the overlap for the tangent stringers and the drilling holes for the screws are marked.

the prepared piece of plywood is flow-coated with epoxi




The hull-side scarfing joint is prepared. First roughly by using a hand-plane ...

... followed by using a belt sander

Stringers and bulkheads are coated with epoxy. First thin with a paint roller, ...

... then thick with a notched trowel.

Small metal latches are temporarily bolted to the hull to hold the radius segment in position until it is screwed in place



The radius segment is positioned ... 

... and then screwed in place

Done. The latches can be removed again. The screws are removed, before the second radius layer is applied.

1000 Hours Working Time Completed

Working time been invested: 

1000 hours!

Video: Planking A Hull Segment

Planking Hull Segment From Bulkhead G To I

12 steps for planking of a hull segment

1. Mark areas to be planed by a straightedge and a piece of chalk.
2. Fairing stringers by a plane. For fairing the bulkheads it is more recommend to use a belt sander.
3. Clamp a suitable piece of plywood board to the hull.
4. Mark the boundaries of stringers and bulkheads on the inner side of the plywood board.
5. Remove the plywood board from the hull, cutting-out the outer shape (don't forget the surplus for the scarfing joint) and drill the screw holes.
6. Put the plywood board again to the hull and fix it by some screws.
7. Mill the joint for the radius segment. I use a motor plane. Works better than a router.
8. Remove the plywood board again for milling the scarfing joint.
9. Flow-coat the inner side with epoxy.
10. Coat stringers and bulkheads with epoxy. First thin with a paint roller, then thick with a notched trowel.
11. Put the panel back to the hull and screw it tight.
12. Remove out-swelling epoxy.

  

Planking Of The Hull Continued



This weekend I have toiled hard and made good progress. I spent 15 houres by planking the midships sections at port and starboard side. Furthermore I faired the stringers and bulkheads by using plane and belt sander at portside aft section from bulkhead G to stern. 

Fixation of the planking scarf

Planking scarf after fairing

Working time been invested: 955 hours

Planking Of Hull Segment From Bulkhead C To G Prepared

Today I faired the stringers from bulkhead C to bulkhead G. The ship's side is just slight curved in this section, so this task was more easy than the same task between stem and bulkhead C.

Stringers and bulkheads after fairing

Prepared hull segment

Stem Timber Attached

Last weekend I have prepared the stem timber from a 30 mm thick sapeli plank. Afterwards I screwed and glued it to the bow. Today I spent half an hour to fair it.

 

Working time been invested: 936 hours