Building a stitch & glue boat in Fiji

Discussion in 'Boatbuilding' started by Saqa, Oct 20, 2013.

  1. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    k, I guess I better get this right and proper and not get lost in terminology and make a critical mistake

    Getting the rubrails out of way, going to use the damanu, its got a nice spring like character and I can bend it and screw/glue it on from the outside

    Sheer clamp is a new terminology for me! My bow cap/deck is shaped like a StarTrek badge and made of two symmetrical halves joined together with a butt plate from underneath almost as wide. All in 9mm ply

    The pointy arms of the that badge will extend to the transom forming flat surfaces to hole out and fit rod holders. The long narrow lengths of 9mm ply fixed to the arms with more butt plates underneath

    My aim was to lift this whole structure into the boat and stitch to the top of the side plates bow to transom and tape the seam with 200 plain. Do I use 450gsm double bias instead on the cap to sheath and overlap to the side plates in the bow cap area?

    Please help with adjusting the gameplan for tomoz so I dont make a mistake at this stage
     
  2. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    And do I need to tape under that seam as well? or will a fillet do?
     
  3. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 114, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    Normally only a fillet..almost impossible to tape over head

    The multi ply plywood layer on the. Outside...the topsides ......will produce a good gluing surface for the deck and something to fasten your rub rail too
     
  4. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 114, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    Common sheer clamp detail for a small ply skiff.



    http://[​IMG]
     
  5. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Gracias Michael

    Some progress today. Ripped the 10x1 damanu plank today into four 26mmx20mmx4.3m strips to use as rub rails and the inside wall of the gunwale. Also ripped a 75mmx26mmx3.5m and then ripped it diagonally for the strakes and a 150mmx26mmx2.5m which will be tapered to a point and fixed under the keel as a protector/pad

    Also ripped up a few 20mmx20mmx1.5m battens to use as under deck supports and cleats and things

    Cut up the 9mm ply that will form the gunwale tops/bow cap thingy. Reinforced it with 200mm wide damanu strip running full width across the inside and out side vee of the bow cap thingy, thats curing now. Planed the edges of that damanu so that it sits flush with the hull panel inside

    Have not fixed anything cut today to the boat as still quite a bit unsure on moving forward. At the moment I think I will cut smallish triangles from the damanu that will fit under the full width of the gunwale ply top and brace and fix to the inside hull wall. A number of these placed a metre apart or so should result in gunwales that can be stood on without worry when entering the boat from the wharf

    Another thing I am wondering is Purbond vs epoxy for attaching all the inside bits. Will fillet with epoxy when it comes to things like the bulkhead frames and stringers. Wondering about the purbond for the gunwale and deck fixtures as well as frame and stringer bottom to hull. Tested the Purbond and it foams and fills gaps nicely
     
  6. upchurchmr
    Joined: Feb 2011
    Posts: 2,865
    Likes: 89, Points: 48, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Saga,

    I don't know anything about Purbond, but a foaming adhesive "probably" will not have as much strength, since there is less material there.

    Make a simple test piece of each and break them. Much more valuable than opinions, unless someone has done the same already.
     
  7. AnthonyW
    Joined: Oct 2012
    Posts: 115
    Likes: 10, Points: 18, Legacy Rep: 19
    Location: Cape Town, South Africa

    AnthonyW Senior Member

    Saqa - sorry for the late reply. I thicken with timing (it gets pretty warm in Cape Town) by applying it very late, and with a bit of flour depending on the spot and if it is structural and will get another patch on top. Apologies if that sounds a bit vague, depends on the area. And I have yet to extensively fair it.

    Wonderful to see your progress. Bizarre flooding localised to my nieghbourhood has interrupted my progress I am afraid. Please keep the pictures coming.
     
  8. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    I have in 19mm MDF sealed cabinet of 60L using ony purbond on the seams and fitted a 15" Earthquake driver that has 75mm of Xmax movement driven with a 1000wrms regulated supply poweramp and it lived a 3 years in a high humidity car boot (fishing gear and life jackets and such in the boot) through Sydney seasons. Thats a lot of shock loading inside the cabinet as it can create 137db. MDF panel surfaces sealed with PVA and carpeted

    Dont know if it can be compared to the loading and conditions found in the boat but the stuff is supposed to be waterproof, more then epoxy even
     
  9. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Hey Anthony, show us some of your build pics too, m keen to see. I hope you not letting it jell too much by waiting to apply. I did that once and it didnt attach to a carbon substrate very well. Just peeled off when cured and rod bent. Some sanding dust or baby powder might be better then letting it jell

    Speaking of flooding, we in Fiji are at the start of our version of the monsoon season and the river outside my flat has climbed halfway already. The following pic is of a past flood beginning of this year
    Lol I might just chuck the boat over the balcony to launch it for some laughs if it gets bad again :D
    [​IMG]
    [​IMG]
    [​IMG]
     
  10. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    I just did a rough sketch in Inkspace trying to put down on paper what I visualize in my head of how the boat will end up looking. I may not be up on the engineering but I have always thot of myself as not too bad on execution and I reckon if I can get the stringers right then I might be ok. Will paint the hull outer bright chartreuse and inside white with the skinny console hinged so I can drop it down jetski style and use the middle seat for rowing. All the pink bits are decks and seats and will have white upholstery over closed cell PE foam. I am going to all this effort so why not aye :) I can see a much bigger motor on the back in the future too!!
    [​IMG]
     
  11. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Just to update, progress has been very slow. I have cut out pretty much all the bits to finish the inside work. I didnt factor in all the framework requirements in my ply purchase and all the local timberyards are out of stock with now eta on new supplies. I have had to cut out all the undersole ribs from the damanu plank. I didnt have enough left after all that to make the stringers the way I envisioned but still managed to cut out a pair of 3x1 that stick out of the transom at the bottom through a pair of notches

    It has taken days of work with the planer to shape all the hardwood ribs and stringers to follow the hull curvature and lol looks like I have developed rsi in the left elbow. Can hardly lift the planer now

    I still managed to have some funky stringers though. Since they stick out of the transom and run along the edge of my boarding steps, I can install a pair of knees behind the transom too to make the inside walls of the steps that brace the transom from the outside too! This means that my transom will not flex in or out. My inside knees are the two partitions dividing my rear casting deck into three sections so they measure 40cm tall and 60cm long. They are fixed to the transom, stringers, deck forward wall/frame and the deck top plate on their four sides. Do you guys think thats adequate?

    My hardwood rubrails are now attached with screws and epoxy. Hopefully tomorrow will have that undersole framework epoxied in and filleted. How do you fellas feel about tape on this? The wood is 26mm thick and will have thick fillets too. Is tape required?

    I have also received some tentative interest in a fella wanting to swap my 8hp for his 25hp. He feels his boat is too small for the engine he received as a gift from his employer and he wants the frugal nature of the small outboard as well
     
  12. AnthonyW
    Joined: Oct 2012
    Posts: 115
    Likes: 10, Points: 18, Legacy Rep: 19
    Location: Cape Town, South Africa

    AnthonyW Senior Member

    Hi Saqa

    Thanks for the update. Will post pics of my boat soon. Working very hard at the moment so don't get much time on the web.

    The pics of the flooding that side are quite something!

    Do keep up the hard work - hope the elbows and arms recover from all the planing! Your boat will be a real labour of love once complete. I work in an office all day, so a few minutes on weekends to make bits of progress on the boat are tremendously therapeutic for me. I hope it is the same for you.

    I know little about engines compared with other members of this forum, but the swap sounds great. Hope it goes ahead.

    Do post some more pics when you get a chance. I will try and look up how to post pics (I have seen this in a few threads) so I can post pics of my progress.

    Thanks again for keeping us posted. Have a great week.

    PS I have put the first light rails on mine using epoxy and clamps - no screws. Seems to have worked very well and formed an incredibly strong bond. I plan to add a bit of cloth over them, but for nothing more than abrasion resistance (I reckon the rails will take the most knocks coming up to the quay) and if the water gets in there from chips and nicks it could be a problem later on. I have owned a wooden boat before that rotted, not keen to repeat the experience.
     
  13. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Yup I am going to glass the rails too with 200gsm tape

    Yesterday a friend gave me a garbage bag full of offcuts about 50cm x 50cm of what appears to be 200gsm stitched fibreglass fabric. It looks to be woven and stitched 90/90

    Hey fellas, touching on something I mentioned previously. All my undersole stringer and lateral frames are made of 1" thick hardwood. Do I need to tape these too or is the 26mm wood contact adequate with just epoxy and fillets?
     
  14. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Finally finished installing all the undersole frames and stringers. Epoxied and filleted. I am not going to tape them as I feel that 26mm glue width with fillets on either side is plenty strong enough

    Tomoz will checkout a foam product a local hardware store has just got in. Its a one part spray type in a large canister. I am only going to use a product here that wont soak water. I dont like the thot of regular foam as always hearing reports of sogged up foam in boats. If this stuff is not suitable then I am going to shape polystyrene foam and encapsulate them with epoxy to fit under the sole
     

  15. Saqa
    Joined: Oct 2013
    Posts: 482
    Likes: 9, Points: 18, Legacy Rep: 75
    Location: Fiji

    Saqa Senior Member

    Today will be a nice milestone for the build. All interior woodwork is be finished and dry fitted then epoxied in.....only thing left to do would be the sole once foam is sorted
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.