Frames to form the Structure

Now that the first section is complete , we now start making the frames for the next . Jigsaws frames come in three forms , Sheet frames , Bulkhead Frames and Open Solid Timber frames .

This is a Sheet Frame , basically formed from a single 12mm sheet of Plywood with a solid Timber reinforcing structure  made from 25mm thick Kauri  . Strength primarily comes from the plywood , the solid timber stabilises the plywood structure and allows for edge fastening of the longitudinal stringers ( you can't edge screw plywood ) . We use a number of these frames between the first two bulkheads as they also form the sides of Fluid Storage tanks for Sewage , Grey Water , Rain Water and filtered water .

 

 



 

This is a Bulkhead Frame , again it has a solid timber reinforcing structure ( 38mm thick this time) , but  both sides are covered in 18mm Plywood ( one side still to be fitted to this frame ) . These are the primary structual entities in the vessel and link from one hull , across the accommodation levels and back down to the other hull . Jigsaw has five such frames across her width . They also form watertight bulkheads in the hull thus splitting each hull into five  sealed sections . 

 

 

 

 

This is the Open Solid Timber Frame , these get used in the second,third and fourth sections of each Hull , Made from 150 x 38 mm Solid timber these allow for the open storage area's in the hulls . The timber sections are half jointed at the side intersections and will be fitted with plywood reinforcing across the joints ( not yet fitted to this one ) , the bottom intersection is butt jointed with 38mm solid timber on one side and 18mm plywood on the other ( this is also the hull floor level ) . Each Hull has eleven of these frames , Five Bulkhead frames and Five Sheet Frames , ( thats a lot of Frames ! ) .

Better plant some more Tree's .





 

 



The Birthing Process

The Baby takes its first look at the Big Wide World

Bit by Bit it moves further Outside , But things are getting Tight !

Looks like the Clearance to the roller door is OK , but the Outer  Cladding is getting very close

Very Very close , now down to  6mm ( 1/4 inch ) clearance  !!!

If this Baby gets Stuck ! ,there's going to be tears !  (  alas  Mine ! )

Further out now , but still only millimeters to spare

And then all with a Rush , it bursts forth into the World !!

Bit of a Stumpy Baby this one , as is only 1/4 grown

This side looks a little strange as the Dual skin and the fiberglass don't go all the way
to the gunwales , this is because there is more Boat to build on top of this Piece ( Jigsaw 's
Pieces go Horizontal and Vertical, like any Jigsaw ) and this allows an overlap of the Skin from
the other Sections so as not to concentrate all the breaks in the skin at a single point . The other side doesn't have this problem due to the Wingdeck section between the Hulls .

Feel the Conflict within us

I build Jigsaw with an internal conflict , Its a Houseboat , not a show boat or a Gin Palace , not even a Racing or Pretty  Little Sailboat . The Question is ? , just how much time do I want to apply to the attainment of a perfectly smooth finish . I don't want it to be ugly  , but I don't have time to waste .
Its a BL''''DY BIG BOAT .

 After an initial round of fairing and sanding ,we finally got around to the fiberglassing , a single overlapping ( at the chines and keel ) layer of 12 oz ( 400gm ) biaxial cloth and West Epoxy Resin . Used Peelply for the first time during this phase  , interesting stuff , seems a bit of a waste of cloth but worth the result . Where I got the cloth to work correctly , the surface was damn near perfect , almost ready to paint , on other areas it still need a little re-work , but far less than if I hadn't used it at all . So after another round of fairing  we started in on the Paint job , using a 2 pot Epoxy Primer to start the process we applied it with a roller rather than spraying ( Hey , its a Houseboat ) , the fumes are bad enough with just rolling it on , hate to think what its like if you spray it  .
Its almost time for this section to be delivered into the world ( that is , if I can get it out of the garage door ) , it will then be positioned in front of the garage and we can make a start on the next section that will use the first as its joining template . Once the shape and connection of the second section is confirmed , then this initial Bow section will be removed and Rotated to its proper orientation .
Should actually start looking like a boat !!

Bugger !

We have had a little Bad luck  ( Bugger ! )  , Used a 2 pot Epoxy Fairing Mix on the Conical stem and for some reason it refused to set , dunno if I made a mistake , or it was a bad batch or just the weather was too cold , but after waiting for 7 days for it to harden up I gave up and stripped it off . Went back to West Epoxy and the fairing powder , hardened overnight and was finally able to Shape off the Stem .

 

 



 





Have also made a start on the Capping strip , the front section of this is made from 4 laminations of timber over the curve of the forefoot and matches up with the bottom of the conical stem  . The Aft piece will be  solid timber  as there is no significient curve to deal with .
These pictures were taken just before I fitted another 2 layers of fiberglass over the stem and capping strip to finish off the sandwich construction of the Bow . The entire boat will be covered in a layer of fiberglass which will overlap at the keel , chines and stem , with an additional reinforcing strip along the keel and chines thus giving a total of  4 layers of fiberglass over the stem and 3 layers over the keel and chines .
The rest of the Hull is being sanded and faired and no matter how much I tell myself ( I love sanding ) , I don't actually  , so the quicker that this gets done the better .

Gluing , Screwing and Torture

Someone asked me the other day , " What are you up to ,on the Weekend " , I repied with " Gluing , screwing and Torturing ( Pause )  sheets of Plywood . Funny thing  , he gave me the strangest look !
Doesn't Everyone ??

With the Bottom 2 layers complete  and the second skin on the sides progressing from the front , I have also made a start on the conical bow section . Made from strips of 25mm timber narrowed at one end ,layed vertically over some temporary forms to create the shape  . Epoxy glue is forced into the gaps between and when set , the assembly will be removed and fiberglassed on the inside .

Removed the Conical bow and have added the layers  of fiberglass  to the inside of the strip planks , this can now be glued back into place and we can continue with the fairing of this section into the main Hull .
( OH No  , more Sanding !! ) .
 Additional layers of fiberglass will be added on the outside once I'm happy with the shape and we will have created a nice solid timber strip plank sandwich .  ( Tasty Huh )
I'm glad I kept the Conical Bow design  , it makes a real point of difference over the typical plywood boat design .

Best Laid Plans

Well things didn't quite go to plan , pushing the go-Kart managed to Aggravate my Back a bit  , so progress wasn't as much as I would have Liked  , but some has been made .

The first skin on the bottom has been Glued and screwed into place with most of the second layer as well . Have been forced to start on the sides as well as edges need to overlap each other on the rear section due to the Landing area on the solid timber chines . The last part of the bottom section should only be 1 or 2 pieces , as the twist is less in this area so narrow strips are not required . Once the sides are on I will be able to make a start on the conical bow section , that should be a nice little challange ( we shall see ) .  Must start training my brain for the other upcoming major issues ( " I love sanding " , " I love sanding " ) Yeah Right !!

Return of the Mischievous Poltergeist

Its amazing the things that occur during the construction of such a project ,  tools that you put down for a second amazing disappear for long periods at a time , only to be found later ( or sometimes not at all ) in a totally bizarre place . How did they get there !! . Either a Mischievous Poltergeist is playing games with me or looks like i need to tidy up my workspace again ! .

We have started to skin the BEAST ,

This is the first of the two layers of 12mm plywood , the rear section was done in a single sheet , the forward part is done in 150 mm strips due to the twist in this section ( due to a rather deep forefoot ) . This changeover is also marked in the change in the chine as the connection between the sides and the bottom changes from an overlapping joint to a butt joint .  The strips aren't glued into place as yet , just held by a couple of screws , the angular pattern creates a concave shape in the strips so I let them stress relief in the shape for a day before i glue them  , makes the gluing easier . The second layer goes on using a reverse angle creating a convex curve which holds them  nice and tight to the first layer .

Managed to secure a shipment of marine plywood at a good price , so got a test shipment of 25 sheets , stuff looks good so I will attempt to get some more , but am seriously running out of space , there is now even less room between the boat  and the walls of the shed .

Hopefully should make a bit of progress this week as have manged to take a few days off work , between taking my son to the go-carts , and the other maintenance work that needs to be done around the place , here's hoping anyway .

The Curse of the Second Guess

There are times during the construction that you look at your Creation and Wonder ?
Does that look right? , Should that be Straighter , Bendier ,Smaller or Bigger , Does what looked right  on a piece of paper or a Computer Screen really translate when it forges it way , full size in the real 3D world . You just keep going saying quietly to yourself that your sure its supposed to look this way , even though those niggley questions rattle around in the back of the head to annoy you !.

But slowely it grows on you , Your 3d creation starts to fill in , and you feel more at ease .
Framing for this section is almost complete , just a bit more tidy-up planing to get things nice ,true and ready for the 2 skins of plywood to skin the beast . This framing has been slower than expected , mostly due the laminated stringers,chines and gunwales etc ( only had so many G clamps ) , the next 3 sections ( rest of the Port Hull ) should be quicker as these members will be single pieces of solid timber as there is much less bend and twist to deal with .
Three months down , three more to go for this first section , and then hopefully 4 months for each of the sections to follow , Then all again for the Starboard hull  . Connect the pieces then my creation hits the water , and then the Hard work starts , but hopefully that will be full-time construction rather than this part-time stuff .  There must be easier ways to retire !!

To Scarf or not to Scarf

THAT IS THE QUESTION

This is a typical scarf joint !

Its a Pain ! , takes lots of time to make and to be done correctly , needs a reasonable level of accuracy . I need to do lots of them as the length of a piece of wood doesn't always ( most times in fact) match the length required for the job . This is the two piece lamination of one of Jigsaw's Gunwales ( side top edge of Hull ) . Currently I make them by rough planing the angular cut using a power planer , then fit into a jig I created and using a router to finish the cut to a more accurate version . Originally I used a bench saw to make the initial cut and then finished with the router , but typically my bench saw has quit ,the blade started to wobble more that it should and under investigation found that a small bronze bush had become worn and havn't been able to find a replacement . My tools are failing already !!!  .

Jigsaw by Name , Jigsaw by Nature

As mentioned , Jigsaw's hulls are made from multiple sections  , each approx 5 meters in length and over 2 meters in width . These are required to be joined before they hit the water and the process of this joining has gotten more difficult since the decision was made to build in wood rather than steel . The connection points should be seamless , structurally sound and connect quickly  , not an easy proposal .

Skin connection is relatively simple , the inner skin of 12mm ply will butt up directly against its opposing section , the outer layer is held back 200 mm from this edge and a 400mm panel is fitted across this gap as the hulls are joined together , another layer or (butt block) is fitted on the inside of the inner skin across the 850mm distance between the transverse frames .

This gives 3 layers of ply with staggered joints across this section of the hulls , and is likely stronger than the rest of the hull .

Connection of the Chines , Stringers ,Keel and Gunwales is more complex as these are constructed of lamination's of solid timber , but again one of the lamination's is butt jointed to its opposing section ( outer piece this time )  , the inner lamination is scarf jointed with a additional section added and a inner reinforcing layer of fiberglass is added for additional strength in a U section covering the top and sides of each of the longitudinal structures.

The fiberglass U section provides a stronger connection than a third layer of wood as it attaches to a far greater surface area.

Technical Spec's

LOA      19.8  meters
Beam       8.4  meters
Draught   0.95 meters
Displacement   38000 kgs
WingDeck Clearance 1.2 meters

Main Power  2  x   150 hp Inboard Diesel

Hull Construction is Ply ( double skin 12 mm marine ply ) over Frame with an outer Layer of Fiberglass , Framing is longitudinal stringers over transverse frames and watertight Bulkheads .

The Beast Reveals Itself

After 8 weeks of Part-Time work ( Evenings and Weekends ) the shape of the beast is finally revealed , well the first 5 meters of it anyway .  Jigsaw's hulls are created in separate sections to be joined at a later stage , you may notice the rather wide stem , this is the base of the conical bow section  to be constructed using a vertical strip plank process . Originally the houseboat was to be made in steel ,  due to cost constraints we changed to plywood but I still wanted the conical bow that looks so good in steel . The first lamination of the Side Chines , Stringers and Gunwale's has been fitted  ,another is still to go and I have still have the bottom stringers to fit .

THE BEGINNING OF A DREAM

This blog will catalog the Construction of  " Jigsaw " , A 20 meter HouseBoat Catamaran that hopefully I will be able to retire on in my Latter Years . Construction is currently in progress using Fiberglass covered Dual skin Ply over Frame technique for boat construction .
Why " Jigsaw " , how else do you build a 20 m boat in a 6 m garage , Piece by Piece  of Course !!



Although designed as a Houseboat ,this vessel is well capable of Coastal Crusing  ,  1.2 meter wingdeck clearance , multiple watertight compartments and "Hull within a Hull"  Design allows for a greater range than your normal type houseboat and the strength to withstand the varied conditions it may encounter .

The Hulls are tied together with 5 primary bulkheads that transverse across the Main deck and Lock into the watertight structures within the hulls . Primary  accommodation is all above the  main Hulls   , these are only utilised as Storage and engineering area's but still have normal head clearance for good access . Main Deck consists of 2 Large Staterooms forward each with ensuite and 2 smaller staterooms aft of them with shared ammenities , aft of these are open sidedecks for external access and aft of this is a Workshop Area ( ManCave) .

Upper Deck consists of a Lounge area  , Kitchen  and Main Bridge with open areas either side of the Forward section .