User Tag List

Results 1 to 15 of 284

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Jun 2010
    Location
    Rotorua New Zealand
    Posts
    1,129
    Thanks (Given)
    14
    Thanks (Received)
    6
    Likes (Given)
    157
    Likes (Received)
    40
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Wellcraft Nova undergoes a conversion from Sterndrive to Outboard.





    The Project.
    <O</O



    Inboard/outboard to outboard conversion on 1985 Wellcraft Nova with Indmar Vortec 320hp 5.7 litre V8 engine and Alpha one drive. Replacement engine to be one or two Johnson 4.0 300hp V8 outboard engines.


    <O</O
    The boat arrives. We remove the engine and leg. We then removed all appendages from the transom both inside and out.
    Prior to purchase we could see from photos that there had been some restoration done to the transom. Prior to purchase I had been assured that both the floor and transom were solid and that the boat had recently undergone a $US15k refit on mechanicals and transom etc.
    <O</O
    On Closer Inspection. We foundthe phrase restoration was not correct. It appears as though poor quality repair work had been done on two or three different occasions on the transom. It became very quickly apparent that the whole transom would require removal through to the glass and gellcoat.
    At some point in it’s more recent history heavy Woven Rovings glass had been laid over the transom, engine bearers hull sides etc, it covered everything up to and including the first bulkhead forward of the transom. It had been poorly applied and had not been clearly thought out. Some of the glass we were able to rip off the substrate. Some areas the cloth had not been wetted out properly and had consequently not stuck. Much of the substrate had apparently not been prepared for glassing contributing to the poor adhesion of the glass. Excess resin had been allowed to accumulate at the base of the transom and require considerable grinding to remove. This excess was between ½ and ¾ of an inch thick in places.
    <O</O
    We removed more than one full rubbish bag of grinding residue (dust). The positive was the removal of plenty of excess weight.
    <O</O
    Rebuild preparation. The transom removal was quite straightforward; the removal of the recently added glass cloth was time consuming and tedious in the extreme. I have decided to remove only that which is necessary for our transformation. So complete removal on the transom and parts of the existing engine bearers, which we will need to laminate to. A straight edge showed us the remaining laminate on the transom was fairly straight and would require no rectification.
    <O</O
    The Plan. We plan to build a pod on the transom and incorporate a boarding platform on either side of the engine(s). We have purchased one Johnson 4.0 300hp V8 outboard to power the Wellcraft. However I am not convinced one engine will give me enough speed so the reconstruction has to be strong enough to take the weight of two V8 outboards with minimal alteration. The pod will provide positive buoyancy when the boat is at rest.
    <O</O
    To support the weight and stresses imposed by possibly two V8s we plan to build longitudinal bracing glued and glassed to the existing internal engine bearers and forward to the first bulkhead. These bearers will extend aft through slots in the reconstructed transom and will form part of the pod structure. Internally the braces will also go to the full height of the transom/topsides and will extend forward to tie the transom to the aft topsides giving additional support to the topsides/hull join.
    These braces will be constructed from 1 thickness of ¾ in thick Okoume/HW ply and then glassed using 1 skin of 600grm Double Bias E glass. The inside layer of laminate will consist of a single skin of +/- 45* 600grm Double Bias.
    Reconstruction of the transom will consist of one layer of ¾ in Meranti/HW ply, This layer will consist of 4 separate sections. The internal transom will then be glassed using two layers of 600grm Double Bias E glass with a lighter layer of 100grm ‘boat cloth’ over the top. The boat cloth is only there as a sanding barrier so we do not reduce the structural integrity of preceding laminates. Some areas will receive a second thickness of 3/4 ply with another layer of 600grm DB glass to further support the installation of trim tabs etc.
    <O</O
    Corner joins will either be glue-coved and glass taped over or will have Cedar timber fillets glued into the corners and then glass taped over depending on point loading for that particular join.

    Resins and fillers will be by West Systems.

    <O</O
    The pod will be constructed from Okoume ply with the pod base for the jack plate attachment built using 4 pieces of ¾ in Meranti ply. Each ply join will have two layers of 600grm Double Bias E glass with the second layer extending 1 ¼ past the first. The internal corner will only require one layer of 600grm DB with an overall finished thickness of +/- 3 inches. Again internal corner bracing for the pod will be provided by Cedar timber fillets glued and glass-taped over. Other areas of the pod will be constructed from ½ in Okoume ply.
    <O</O
    Moving on. Today I started to prepare the original engine bearers ready to accept our bearers. Problem. The existing bearers have rot in them and the internal cavity on both sides contained water and all timber was soaking wet.
    <O</O
    So today I spent the day removing the original engine bearers. Yet another day of grinding with probably most of tomorrow on the grinder as well. That hopefully will be all but the end of the grinding preparation.

    Photos will be added soon, now it is off to the shower.

    Last edited by Smoking Joe; 12-11-2011 at 11:03 PM.
    Wellcraft Nova 230 XL, 300hp Johnson.
    Seahawk 45 Sport Fisher, twin 306hp Volvo.
    Steadcraft 28, Yanmar 300hp. Sold.
    Markline 800, Volvo 300hp. Sold.
    Haines Hunter V19, Volvo 170. Sold.
    16ft 6in Figlass Sidewinder, 140 Suzuki. Sold.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Aeromarine Research