At the end of June 2011, I published a post about my idea for moveable side seating in cruising dinghies. The idea is that side seats can be used if prefered (although I like to sit down low in the boat with my weight near the windward turn of bilge) and can also be removed at a moments notice. Most importantly, if they are slid into the centre of the boat they make an excellent sleeping platform, well above the bilge water.
The Phoenix III built by Paul Hernes, showing the side seats in the standard location..............
...........and slid together to form a nice sleeping platform............
.....or removed altogether.
You can find my original post at this address
I am continuing to work intermittently on a First Mate in my workshop - she gets attention when glue is curing on other jobs. Last week I installed the rails to carry the removable side-seats/sleeping platform, and Im delighted to say that in First Mate, the seats are more than 26 inches wide at the upper part of the body when slid together. Here are a few pictures of the rails: -
Here is the seat rail glued and screwed onto the aft face of the midships frame. This frame is made from 12mm (1/2") marine plywood, with 38mm x 12mm (1-1/2" x 1/2") behind where the screws go through. The whole thing is very strong, and the seat rail would be fine with just a glue joint. However, the silicon bronze screws make it simple to position when the epoxy is slippery, so they may as well go in! The rails are positioned to carry a side seat which is 31mm (1-1/4") deep - these will most likely be 25mm (1") framing topped with 6mm (1/4") marine plywood.
A close-up of the aft rail, which attaches to the semi-bulkhead at the forward end of the stern seat (i.e. the "stern sheets"). The centre cut-away is just to allow positioning of the screw-in hatch to that particular buoyancy compartment.
Another shot of the aft seat rail with the rowing foot-braces on the floor below. These foot braces do double-duty as structural stiffening elements as well
This seating arrangement will make First Mate (and Phoenix III) very versatile cruising dinghies - my favourite type of boat bar none!
The planking was completed in a total of 320 working hours.
December was mostly spent in fairing (smoothing and shaping) the hull, and cleaning the inside of excess epoxy.
Pencil marks were spread across the hull. As the fairing progressed, removing any high spots, the marks disappeared.
The FestoolRotex was the original tool used. It is an aggressive cutter. It has a 6" disc and is a combo rotary and random orbit sander. It worked best for cutting down the high areas of epoxy, and later for aggressively cleaning up the inside.
The Hutchins Eliminator with its 8" disc, is a rotary sander that blends high and low areas the best.
An inline sander was applied to a "fairing board". It will be used in an attempt to create the "ultimate smooth" for the pre-glass finish.
After smoothing the high spots, any low spots were filled with a mixture of phenolic micro spheres, wood flour and epoxy. The wood flour is for non-sag structure, while the micro spheres make the sanding easier once it has dried.
Richard dons his Tyvek (AKA sperm suit) with his 3M Breathe Easy self contained positive pressure hood for the sanding jobs. Cedar and epoxy dust are a bad combo.
The process involved frequent sweat breaks.
A more tedious job than the planking....
After the highs and lows were smoothed, a mixture of epoxy and wood flour was used to fill all screw holes and other voids.
The inside was cleaned up with the aggressive FestoolRotex. I finally climbed inside to view the job. The pressurized hood was an absolute must for this job.
The laminated frames and bulkheads as structural supports are clear.
This is the view looking up toward the engine compartment and lazarettes.
The holes are baffles between the water storage compartments under the sole. All surfaces, hole interiors, etc will be meticulously glassed and epoxied. No water will be allowed to touch any wood. The center board configuration makes drainage of bilges and water compartments slightly more complicated, as there is no right to left connection or central bilge. Since numerous bilge and water pumps will be necessary, we will look at it as bilge and water pump redundancy...
The centerboard box meets up with the bulkhead to form the back of the galley sink cabinet.
The plan for the bulkheads is to cover them with white painted bead board and trim in mahogany, for a very traditional, light look. Most of the "walls" will be covered by cabinetry.
Between these two rounded bulkheads is the Navigation Table. Note the feet working on the outside of the hull...
This is looking forward from the saloon into the storage and head area.
Here is a good view of the laminated frames that create the open area in the main saloon.
The end of the month was when the boat was made mobile for the first time!
The strong back was detached from the floor, and a series of 8 casters were placed under custom boxes. She can be moved by using a little lever action.
Now that she has her own rigidity from the planking she will be able to be pushed from side to side in the small room she inhabits. This will allow her to be positioned better for the diagonal veneer application. Next step...order the veneer.
The grand total of working hours to date is 1150 hours. That is with 13 "no work" weeks.
Lets see what 2010 will bring! Peace and health to all!
All of the hull panels in First Mate, including the narrow flat bottom panel,are made from 6mm/1/4" marine plywood. Wayne Jorgensen, who helped build the first boat from the design to hit the water, expressed some concern about the stiffness of such a thin bottom panel. I wasnt particularly concerned, as the panel is only 856mm/34" wide at the widest point, and is very well supported by the centreboard case, 6 bulkheads and frames, and most importantly, by a 66mm x 19mm (2-9/16" x 3/4") external keel batten firmly glued to the bottom of the boat. In addition, I sheathed the boat Im building with 200gsm/6oz glass cloth in epoxy.
In a beach-cruiser, light weight is of critical importance for a solo sailor, and I also wanted to economise on plywood, getting the most possible out of standard sheets - it made sense to use a standard thickness for all panels. Having said that, there is nothing to prevent you from using 9mm/3/8" ply for the bottom panel if you wish.
As part of the design, I drew an adjustable set of foot braces to make rowing more efficient, and also to give something against which to lock your heel to prevent sliding across the boat when heeling under sail. These foot braces gave me yet another opportunity to stiffen the bottom panel. Following are a few images of the set Ive just installed in the First Mate which I am (slowly) building: -
An overview showing how the side rails of the braces are glued to the bottom of the boat, and extend forward and aft to teminate against the bulkheads. This is very important, because terminating a stiffner in the middle of a sheet of plywood risks the formation of a crack in the plywood eventually. Note how the side-deck knees in the background are tapered and lead all the way down to terminate on the chine between the bilge panel and the topside panel.
Blocks to locate the foot brace. In this photo the longitudinal rails had been glued into position, but the blocks were just dry-fitted. They were subsequently glued to both the rails and the bottom panel
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Three photos showing the foot brace dropped into the three different locations. The longitudinal rails are rounded down at the forward and aft ends to allow drainage of water - sort of like an open limber.
With these longitudinal foot-brace rails in place, along with the external keel batten on the other side, the maximum un-supported width of the plywood and external glass sheathing is about 210mm/8-1/4"
There are quite a few examples of First Mate on the water now, but except in photographs, I havent had the opportunity to see the boat sailing.
First Mate with the sprit rig option
I designed this boat for my friend, Ian Hamilton, who wanted a Phoenix III but didnt have the confidence to tackle such a building project. However, having previously built a Bolger Cartopper, he felt that a stitch-and-glue version would be within his capability.
As it turned out, Ian never did build the boat, so I came up with a deal where he would pay for materials, sails, trailer etc., and I would build the boat in my own time. This approach saved him a lot of the money normally required, and it allowed me to test the panel developments I had drawn - the most critical element in a stitch-and-glue boat design. A symbiotic process. The problem from Ians point-of-view was that once I had proved the panel developments, there was no pressure on me to finish the job!
The stage at which Ians boat lingered for a long time
Well, Ive gradually got Ians First Mate finished, and weve had three outings to carry out "Builders Trials" - Im absolutely thrilled with the results so far!
The video link below shows First Mate sailing off Manly, which is a bayside suburb on the south-eastern side of Brisbane, the State Capital of Queensland, Australia. Conditions were good, with about 15 knots of wind from the north-east, kicking up a short, steep chop. The rig on this particular boat is the 76 sq.ft. balance lug, but Ian will probably purchase the 104 sq.ft. sprit rig at a later date. Because both rigs use the same mast, in the same location, it is quite feasible to have interchangeable rigs for different styles of operation.
I was the one with the camera, and Im afraid that there was nothing I could do about the camera shake in the choppy conditions. I was in a 12ft boat which has a quick motion, and was handling the camera with one hand. I have no idea why the final scene is in soft focus....but it is still worth watching. Skipper of the boat was one of my sons, David.
As some of you may know, I have a First Mate under construction in my shed. I started her a number of years ago, with the aim of testing the panel developments for the design prior to releasing the plans for sale.
The significance of the need for testing when dealing with developed panel shapes in a stitch-and-glue design is that it is the size and layout of the hull panels which determines the three-dimensional shape of the finished hull rather than relying on an internal skeleton which has been carefully plumbed and shaped, and around which planking is laid.
One is built from the outside-in and the other is built from the inside-out.
Here is a carefully set-up hull on a strongback showing the stem, internal keel (or maybe keelson) and a large number of transverse molds around which the planking will be laid. In this case the internal structure determines the shape that the planking will adopt.
In this photo you can see the bottom panel of First Mate having the bilge panels attached using cable ties. The boat is already taking up a three-dimensional shape without any internal framework to help. This system relies totally on the accurate design, marking and cutting of the panel shapes.
This is the very same hull in a photo taken about ten minutes later. The topside panels have been attached with a small number of cable ties and the final shape of the hull has already been defined.
The fundamental difference between stitch-and-glue and any other sort of construction (with the possible exception of Birch Bark canoe building and some forms of Scandinavian "built by eye" lapstrake (clinker) building) is that it is the shape of the cut hull panels that determine the shape of the assembled hull, rather than the rigid internal skeleton as with a conventional boat.
Im not saying for one moment that one system is any better than another, but rather I am trying to illustrate why it is so critically important that stitch-and-glue hull panels be absolutely correct in their shape.
Hull panels for a scale model of Three Brothers showing how different the flat panel shapes are......
......compared with when the panels are assembled.
Anyway, to get back to the First Mate that Im building, once the panel shapes were proven? to be correct, there was no urgency in finishing the boat. This may have annoyed my friend Ian Hamilton somewhat since the boat was being sort of financed by him. My boys and I have reluctantly agreed that she may end up being his boat (dont panic, Ian, she is yours...), but there were other things on the books which were more urgent, so First Mate sat in the corner of the shed.
Now the project is up and running again and here are a few photos: -
Foredeck glued into position after having been thoroughly epoxy sealed on the underside. There were three full coats of WEST System Brand epoxy used, with each subsequent coat being applied while the preceding layer was still chemically active, so that a proper bond was obtained. The deck was glued into position while the final coat was still tacky.
Centreboard case treated with epoxy.
Support beams for the stern sheets (aft seat) being treated with epoxy. The inside of the buoyancy compartments have already been treated and thoroughly painted with an epoxy primer/undercoat
Floor of outboard motor splash well glued into position, having been thoroughly sealed underneath
Aft deck being dry-fitted using silicon bronze screws. It was subsequently glued into position using the screws and additional silicon bronze ring nails
Aft seat (stern sheets) glued in after having been epoxy sealed. This view shows how much emergency buoyancy is contained in the sern compartments - this is exactly the same layout as in Phoenix III.
The two 12mm (1/2") plywood centreboard halves being laminated together with WEST System Brand epoxy. In the past I would have vacuum bagged such an assembly, but I lost my compressor in the January floods (the compressor drives the vacuum-generating venturi) so I have had to revert to standard methods. Note the large number of screws which help pull the two laminations together, along with clamps and lead weights. Most importantly, the screw holes allow trapped air to escape so as to give a good, solid bond. The screws are removed just as soon as the epoxy has set, which is the stage you can see in this photograph.
Rudder blade halves being marked out. Note how I have drawn the grid at full-size on the plywood.
Home-cut phosphor bronze plate used to spread the loads from the rudder gudgeon nuts. This is the lower gudgeon mounting viewed from inside the aft buoyancy compartment. It is only dry fitted at this stage, and will be set in bedding compound when fitted permanently.
Marking the top of the rudder blade lamination using a compass
Using a spline to mark out the gentle curves
Using french curves to mark the tight curves
Rudder blade halves spread with WEST System Brand epoxy prior to assembly
Rudder blade halves glued together over a strongback. Note the good squeeze-out, and just after this photo was taken there were bleed holes drilled in the centre portions
I dont know whether these step-by-step photo sequences interest people, so if you feel strongly one way or the other, please let me know. Eventually the website photo pages will get these pictures in thumbnail form, which loads up quickly, and allows you to enlarge only those which are of interest.
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