Windshield change and soft top to hard top change anlysis

Discussion in 'Boat Design' started by Nidza, Apr 21, 2023.

  1. Nidza
    Joined: Nov 2016
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    Location: Belgrade, Serbia

    Nidza Senior Member

    Hi all, I think I am in the right topic category (design), please, correct me if not. It is about functionality and estetics of the above water design rather than hydrodynamics (but in case of hard top, weight can be added affecting hydrodynamics).

    In short, I am thinking of either
    • changing/redesigning only the windshield and keeping the canvas (cheaper path), with some small improvements to canvas (canvas and/or canvas holding pipes and/or windshiled) or
    • changing/redesigning the windshiled and adding hard top instead of canvas (more expensive and more complicated path).

    The root cause of the windshiled change came from the following list of issues (random order):
    • No local company which could build curved glass as required, only plexiglass possible
    • Plexiglass loses clarity in ~2-3 years and then action is required or you have to bare with the bad visibility
    • It scratches easily, so no windshiled wiper possible, rarely required, but if captured by rain storm, it is a limitation to some degree, depending of the rain intensity (or even waves spray, but I had that experience only once with "ugly" waves)
    • No perfect sealing between the windshield frame and hull (the shape of brass windshiled frame is made for rubber seal from 1960s, not easy to find high quality proper shape rubber seal which lasts and shape not perfect for using silicone/acrylic adhesives)
    • Mid section cannot be open for better ventilation on hot days
    • Assembly/disassembly of windshiled to parts/glass panes is complicated
    The root cause of the canvas to hard top change came from the following list of issues (random order):
    • Current canvas is reaching the end of the lifetime soon (canvas material Sattler Yachtmaster 354)
    • It can be very hot under the canvas, which is especially unpleasant for the "driver" since he seats higher i.e. his head is closer to the hot canvas (very very unpleasant!)
    • There is always some small leak somewhere, some more tolerable, some less
    • It must be remade in ~8-12 years (smaller fixes ~ year 5-6, e.g. some threads must be fixed), again some segments can last longer, while some shorter, depending of the exposure to elements and usage
    • Top canvas is almost never removed, only sides are removed when boat in use
    • Boat is outside 24/7/365

    So, I will list photos and options I am considering with my own conclusions and then I would like to hear your opinions/recommendations.

    So here is the boat as it looks now (when stored and when in use):
    010a.JPG 010b.jpg 001a.jpg 001b.jpg

    So, let's now list the options and I would appreciate if you could leave your suggestions for each of the options, as well as which option do you prefer and why (I will try to list now from the cheapest to the most expensive):

    1. Change nothing, except try to find better sealing option between windshield frame and hull. Live with curved plexiglass. Improve canvas with new canvas slight changes and slight cahnges to canvas and/or canvas holding pipes and maybe some other smaller sections.
    2. Change only the windshiled, but keeping the same canvas, e.g. making the same/similar looking windshield frame of fiberglass (integrated to the hull), so that there are no leaks between the windshiled frame and hull. Windows (all glass) would be either mounted by rubber seals or glued (adhesive or double sided tape) to the windshiled (what is better?). Now, here is a small catch since I want to avoid curved glass and I can do it in two ways: a) Make the same shape of windshiled as is to preserve the curved design of 1960s-70s, but in a way that I move the frame veertical section divider exactly where the curve is leaving me with flat glass panes on the side and on the front, but the price to pay for this is to lose some visibility area; b) to make sharp egde between side and front, completely avoid the curves in design. To ilustrate the visibility loss, below are some improvised photos of those curves uncovered and covered with fender :). What do you think of these options? Of course, some corrections could be made to canvas for improvement (canvas/pipes/fiberglass details). Now, in case of this option, I also can consider the following for the improvement of ventilation. The less complicated route is to make an opening section on the canvas in the middle above the windshiled frame. The more complicated is to make middle window of the windshield which can be opened. As you can see, this option 2 has many different variants, and I am trying to find the best combination. To be honest, I think this option in some variation seems to me the most viable as compromise between the cost and effectivness. But, please, comment. 002.jpg 004.jpg 003.jpg 005.jpg
    3. Make a hard top, but now here are also many variations (inluding rounded or sharp edge of windshield between side and front, as discussed in previous option, as well as opening of the mid front window). The first question is should I make it only between the windshiled and "radar arch", or all the way to the stern (e.g. because of weight; because the most critical parts to be protected are between windshiled and radar arch; because it will be less hot than with canvas (due to R-value and thickness of materials)). Then the shape of the sides between hard top, windshield and radar arch, e.g. windows could be extended all the way to the radar arch (much nicer, but heavier, better visibility, maybe less ventilation) or to be just extended in height and shortened (less nice, lighter, less visibility (especially with side canvas), more ventilation). So, here are some photos below of same boat with hard top and windshield with explained 2 options regarding side windows. But, mind that I prefer thin top (like the one with shorter side windows on the photo) than "fat" one with more curves due to reducing added weight. On the other side, I prefer extended side windows because it seems much more estetically pleasent to me. Also it comes a question, should I make flat top all the way from windshiled to stern, or tilted, as the canvas looks now when viewed from radar arch to bow and to stern. In case it should be flat, should I reduce the height of the radar arch so that the height of windshiled stays the same as now, or extend the height of the windshiled. I made a radar arch height, so that I can stand below it without hitting it with my head when standing (my height is 1.9m). How about removing radar arch (currently it basically holds cockpit lights, anchorage light and 2 loudspeakers)? To be honest, loudspeakers are the least important since I am mostly enjoying sounds of nature, but cockpit lights come very useful as well as anchorage lights. I see as less work if I keep the radar acrh and it is required holding point of the roof away from the windshield. Maybe it is too much backward located compared to the boat on the below photo. So, please, comment. 011.jpg 012.jpg
    And that is it. I appreciate all the comments/suggestions/recommendations/critics that you will be able to provide me with. Thanks in advance!
     
  2. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Antique!

    If anyone tells you to go to flat panel glass; you won't.

    improve the seals

    find a vendor who can make replacements; they need to use the old ones for templating
     
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    It is my understanding that the brine of the ocean is what leads to early degradation of these plastics. I set my boat up with plastic, but I could get it done in flat tempered glass using the polycarbonate (softer still) for a pattern.
     
  5. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    The yellowing is from UV degradation. Polycarbonates are much softer than acrylics. Acrylics, like Plexiglass can be sanded and polished to remove scratches. The dried salt is abrasive and scratches the material.
     
  6. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Yup.
     
  7. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    I’ve made a couple of solid windshield/hardtops by building in place a melamine mold.
    Get the lines how you want them, and then reinforce it stoutly on the outside before removing and inverting for layup. Don’t forget flanges to fasten the new piece to the existing, inside turned flanges look better.
    You could also probably seal up the existing. I suspect that leakage around the frames is due to flexing, needs to be reinforced from inside.
    Polish the windows and redo the canvas with Hypalon or similar durable fabric for far less $$.
     

  8. Nidza
    Joined: Nov 2016
    Posts: 107
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    Location: Belgrade, Serbia

    Nidza Senior Member

    Thanks for answers.

    Yes, you are right, I made a mistake, it is not Plexiglass brand, it is actually acrylic by local manufacturer, but we locally most often call it plexiglass for obvious reasons. It is now close to 10 years and yes, it is yellowing and paling a bit (due to UV most probably). Scracthes are limited, but wiper would be a no go. In my case, it is not salt rather river sand, soil partilces and probably some soot since I am on river, but I have probably confused you a bit with wave spray. It really can be pretty wavy sometimes due to wind from Carpatian mountains and, in addition, wind is not constant rather blows with some repetiotion rate, similar to Bora wind on Adriatic sea, making waves with high amplitude, low wavelength and diferent heading of almost each wave. If you are unlucky, or a bit crazy to go out at that occasion, it is really tiring process of correcting direction for almost each wave. Also rotating for 180 degree (to go back) is the safest when you reach area sheltered from wind.

    Regarding "Antique", I respect it, but you know, I prefer that Antique serves me and not the other way around. Unless you are talking about the selling value as the key point?

    I can see that most of you are voting for keeping stuff as is, just fixing sealing.

    I found very interesting proposal of using canvas made of Hypalon instead current one made by Sattler. I know the properties of Hypalon, but it did not occure to me to use it for that prupose. I know of the truck trailers tent, but not sure if it is Hypalon or some sort of PVC (some sort which is a bit more UV durable). Many use that one, too. I am aware that Hypalon has much better mechanical and insulation properties, but how important is lacking of that breathability?

    And last, but not least, maybe I did not explain well in the first post. What is your opinion, would the visibility loss be too large in case I make the whole curved areas on both sides of fiberglass (non-transparent), and then only flat windows are left. In that case, I would make all windows of tempered glass, because I am very satisfied with those that I have. The visibility loss is greater since it is curved area, it is tilted and it is wider than current vertical glass separators in the windshield on that place (I tried to simulate that with those photos above with and without fenders in the curved corners of the glass). And the "antique" shape would be kept. I mean, if you would draw it in 2D/3D, blocked viewing angle is wider and in addition it is shifting/moving from bottom to top.

    Thanks for explanation regarding molding process in case of going towards the fiberglass replacement route.
     
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