Common Knowledge Questions and Introduction

Discussion in 'Boatbuilding' started by snowbirder, Jan 1, 2015.

  1. snowbirder

    snowbirder Previous Member

    Hi Everyone.

    I have a new to me catamaran hull, professionally built, but completely empty and bare fiberglass.

    The boat is epoxy, glass and corecell. It's also a performance cruiser.

    I have a lot of basic questions regarding the fit out I'm doing on this hull.

    We have it half primed with primer and mostly all faired on all exterior parts.

    From this forum, I hope to ask a lot of basic fit out questions and get common, off the shelf answers and solutions. Time is of the esence. Trying to launch by May/June and transport the boat 1000 miles to continue fiddling with the interior.

    I am not looking for time consuming rube Goldberg solutions. Simple, standard practice solutions with common, off the shelf products is the idea, even if not marine grade for interior items. These can be replaced when they degrade. Also, the interior of the boat will be bone dry. No dripping leaks, no water ingress. I live aboard and keep things in top shape and drip mark is dealt with immediately. Inside is climate controlled. Air conditioned. Heated. Dehumidifiers as well.

    I'm lacking a lot of common knowledge, basic stuff. I don't know how to make a door on hinges for example. So, there will be a lot of stupid little questions here on these types of things. Here goes!

    Head liner and Wall liner materials:

    I need a extremely light weight, semi rigid headliner and wall liner material. Plastic. White. Have been looking at Coroplast with no ridges.

    In some instances, the liner will start on the ceiling and curve around a radius then down the wall. The sheete only bend in the 4' direction, not in the 8' direction, which will leave a seam. How do I deal with this seam, or what other white, plastic, lightweight liner material can I use?

    Note, the ceiling liner will have lighting recessed into it and wires behind it. Also, money is always a concern, as is gluing it in place. I have been using a HiPurFormer hot melt polyurethane glue gun to do the galley wood work. Amazing tool, great bond. I'd like to glue up the liner in a similar way.

    Need to have a very, very modern, seamless look to everything. No or minimal moldings or edge treatments.

  2. AndySGray
    Joined: Jun 2014
    Posts: 296
    Likes: 13, Points: 18, Legacy Rep: 91
    Location: Cayman

    AndySGray Senior Member

    How do you propose creating the void behind for the light fittings, wiring and of course insulation ?

    I think what you're envisaging is going to be tricky to achieve as a post factory fit out. The large areas of clean smooth and seamless glossy surfaces, curving in multiple different directions, which echo the outside of a GRP boat are made and fitted as a liner at the factory.

    You 'could' create a mould for it but that route is neither cheap, easy or lightweight though it would be strong and durable.

    The issue is that the larger the sheet, the more obvious and displeasing the joins are.

    Some plastics can be 'welded' which can flattened and ground smooth, you can use a soldering iron with a special patterned sheet to melt a texture into the surface to blend the seam with the rest of the surface texture but again the more minimalist the finish the more jarring any imperfections are.

    The common solution is not to try to seamlessly join panels, but to add or use features which the seams can finish at. Accent strips, rails, shelves, maybe an offset U shape channel between the curve of the ceiling and the wall that would allow LED strip light to uplight into the ceiling curve, (now you can use your sheet along the long axis with no vertical seam) if something is clearly íntentional it becomes less obvious - that is the art of the designer. Sometimes things cannot be easily hidden so rather than try to blend in, use high quality materials and turn it into a feature.
    You mention the wood in the galley - bring that same wood into the rest of the boat to tie everyhing together. If done well the wood could 'belong' in a way a seam would not.

    Visit as many boat shows as possible and 'be inspired by' the expensive yachts and the way they are fitted out.
  3. snowbirder

    snowbirder Previous Member

    Thanks, Andy.

    Very good advice, overall.

    Answering your question, I plan to use longitudinal battens to creat a 1/2" or cm size space behind whatever semi rigid panels I use. I'll hot melt polyurethane bond them, possibly adding some epoxy for ultimate strength. This process has worked very well in the galley and for other furniture type indoor items. The hot melt is marine grade, waterproof.

    The plan is to build all of the cabinetry out, then only have smalker sections of area to have to make look pretty, leaving everything inside cabinets unfinished.

    The main salon (bridgedeck) ceiling is huge. This will probably be the most difficult part. Nearly 20' x 16'.

    I have seen white plastic edging that looks like a suspended ceiling aluminum T channel. Maybe that?

    Certainly trying to keep wood and trim to a bare minimum. The wood in the galley is cabinetry only. It won't be visibly wood once sprayed with high build and topcoat.

    I will try to see what I can turn into a fearure...
  4. AndySGray
    Joined: Jun 2014
    Posts: 296
    Likes: 13, Points: 18, Legacy Rep: 91
    Location: Cayman

    AndySGray Senior Member

    That's a really big area to do well, my gut feeling is that if you try to do with 10x (8 by 4) sheets, it could look like a patchwork quilt.

    Ideally need material able to cover the whole span in a single piece, and you may have hit it with the mention of suspended ceiling.

    If you suspend Ally T (inverted) section at 18 inch centers running front to back, you could fill the gaps with the plastic coated aluminium flashing that comes on a roll so no seam, just a straight run front to back. That stuff is very thin (19 thou) but tough and exterior grade, I did a quick calc and got the entire 20' x 16' ceiling coming in around 80 pounds. The tramline effect of the T supports running from front to back should give a pleasing impression of extra length and it would be easier to wire all the lights in a straight line on single pieces, plus no fastenings visible and clean with minimal seams .

    There may be a similar plastic version ?

    Will probably need the void behind (above) to be foam filled for sound and thermal...

    Just my 2 cents but it might inspire another suggestion...
  5. PAR
    Joined: Nov 2003
    Posts: 19,133
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The best common knowledge I can provide is that "money can't make you happy, though it can permit a level of misery you can afford" . . .
  6. snowbirder

    snowbirder Previous Member

    Andy, the boat does have an R value of 8 already just from the inch thick foam it's made of. I don't plan to insulate further. But ok... ill start Googling this one.
  7. AndySGray
    Joined: Jun 2014
    Posts: 296
    Likes: 13, Points: 18, Legacy Rep: 91
    Location: Cayman

    AndySGray Senior Member

    The other question is how 'fair' is the ceiling - if you're painting the wood, could you put a scrape of low density filler, sand with a 'long block' and paint the heck out of it?

    just another thought...

  8. snowbirder

    snowbirder Previous Member

    The ceiling is fiberglass with epoxy and microballoons over it. Partially fair, but looking to save time over full fairing and painting. Plus, a ceiling panel makes for a simple light instasll.

    Wood down in galley is cabinetry. There is no wood anywhere else. It's all foam/glass.

    Using liners, etc to attempt to speed up the build.
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