Aluminum boat rebuilding project - The Vonda Lynn

Discussion in 'Metal Boat Building' started by cthippo, Jun 22, 2020.

  1. brendan gardam
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    Location: east gippsland australia

    brendan gardam Senior Member

    have you used a trolling motor, because they do exactly what you say they can't do. you can even get them with gps spotlock to hold position against the current. my 54 lb watersnake has 5 forward and 3 reverse speeds. the foot control is for manoevering and holding position with your foot while you are fishing.
     
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  2. brendan gardam
    Joined: Feb 2020
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    Location: east gippsland australia

    brendan gardam Senior Member

  3. brendan gardam
    Joined: Feb 2020
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    Location: east gippsland australia

    brendan gardam Senior Member

    may i ask why it is so high. it will be ugly and act like a sail.
     
  4. cthippo
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    cthippo Senior Member

    Mostly just so I can stand up and move around at least in the center.
     
  5. brendan gardam
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    Location: east gippsland australia

    brendan gardam Senior Member

    fair enough.
     
  6. brendan gardam
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    Location: east gippsland australia

    brendan gardam Senior Member

    i did something very similar on a 17 ft hull. it was comfortable except it was like a big sail if there was any wind.
     
  7. cthippo
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    cthippo Senior Member

    Alright, update time...

    I finally managed to evict the really rotten transom while doing a minimal amount of damage. I don't know if they used marine plywood when it was last replaced, but whatever they did use did not stand up. I got a sheet of 3/4" marine and once I get the right hardener, I can laminate the two thicknesses together and cut it to shape, then seal the whole thing with yet more epoxy. I may run a line of fiberglass tape around the edge to further seal it, but I am afraid that if I get too carried away it will not go back into the metal frame that it lives in.

    The last of the parts to rebuild the 90hp Johnson should be here around Christmas and I have a friend coming over the weekend after to help me. We got the motor running on ether, so it should be super happy once overhauled.

    I also picked up 240 feet of 1 1/4 6061-T6 aluminum tube for the frame of the cabin. It's going to be assembled with pop rivets and gusset plates, and then skinned in sheet aluminum. I also got 25 feet of 1" angle stock to hold the windshield in. The hope is to come back in the future and weld in the gusset plates, but right now I have neither the tool nor the skill to do so. Work with what you have...
     
  8. cthippo
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    cthippo Senior Member

    https://www.boatdesign.net/attachme...6/?temp_hash=d86517f0eefba14415ff60a726217b5b

    Transom boards laminated together and drying.

    I knew I had half a bottle of epoxy in the shop from the last rebuild of the Raptor, but couldn't remember which part. Turns out it was resin. Cool, went and bought hardener. Unfortunately I got regular hardener and needed the Silvertip. Cost difference was negligible, but the hour spent driving to to town and back was >[/URL]:(
     
  9. cthippo
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    cthippo Senior Member

    Small update: The motor got overhauled today with new plugs, new fuel and water pumps and a carb overhaul. The carbs were in remarkably good shape for how long it has been sitting and it's age. Motor is a Johnson 88 SPL 90 HP V4 2 stroke that came with the boat. The builders plate says the hull will take a maximumHP of 75 or 80, and judging by the cracks in the splash shield the previous owner liked to drive it wide open. I would like to replace this motor with a 35-ish HP 4 stroke in a year or two for better fuel economy and slow speed operation.

    Next up is to fit the transom board for marking, then cut it and coat it with epoxy before installing it permanently. Hopefully I will get started cutting metal for the superstructure next week as well.
     
  10. fallguy
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    fallguy Senior Member

    This project is going to have some unexpected issues. I am sorry I disengaged, but the Starcraft 16 is a boat I am familiar with. It will not do well with all the high weight and windage and could even roll over on you underway. Surprised noone spoke up.

    The boat will be more difficult to get on plane and will likely plow.

    And the Starcraft 16 will have difficulty planing at 35hp.

    As for my comments about electric trolling motors, I have not upgraded my trolling motor for 14 years and mine would never perform with this boat. With all the weight forward; it will act like a bobber and tend to move in circles. But mine is a 12v and I realize they are making them with much more power now.

    The Starcraft 16 could have been used with a canvas softtop for the Seattle weather, so the hardtop confuses me.

    I realize this is a post where I might come off as an a.s, but we have seen others here asking why their boat feels so tippy and they post pictures of high wheelhouses on vee hulls never intended for such.

    Most likely, the OP will need to find out for himself, but the boat looks like it may well end up dangerous and I am bold enough and callous enough to say so.

    I will see if I can find the tippy boat thread.
     
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  11. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Fallguy has spoken out, and I will second his thoughts - I have had concerns about what you are proposing, and I should have voiced them earlier.

    In addition, from information subsequently obtained from your other posts, even if it is just the two of you on the boat, that will be 700 lbs of added weight with a centre of gravity much higher than the boat's centre of gravity - and the height of this will already have been increased with the addition of the superstructure that you are building.
    When you throw in the windage of the superstructure as well, then I would agree with Fallguy that you may well end up with a dangerous situation unfolding.
     
  12. fallguy
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    fallguy Senior Member

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  13. fallguy
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    fallguy Senior Member

    It should be noted, I well understand the bow of the SC-16 and it is not at all full enough to perform here. The boat in the linked thread is a much larger vessel and a similar sized house in proportion.

    I honestly would not even consider an ultralight house on the Starcraft.
     
  14. cthippo
    Joined: Sep 2010
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    cthippo Senior Member

    I can live with that. I'm starting with the 90 hp because it is what came with the boat. If something smaller only gives me 8-10 knots at a reasonable fuel burn, i am fine with that. The primary use for this will be slow speed work mowing the lawn with the side scan and hovering over wrecks, not zipping around.



    My experience with soft tops is that they are heavy, ungainly, damp, drafty, and always cold. I want to be able to be comfortable using this on rainy, but otherwise calm days when everyone else is home by the fire watching the game.

    Fundamentally, this is not the right hull for this project. The right hull for this project is $120,000 worth of Hewsecraft, which I will never be able to afford. This is the boat I have, which is better than the boat I don't have and will never have. I realize that there is a possibility it will roll over and sink the first time it hits the water, and that it will never be as good as something built from the ground up for this purpose. This is what is possible for me and so I would rather go for it and choose not to have a boat at all. If you can suggest a better hull available for free of cheap then I am all ears. What I am not willing to do is not work on a boat because i can't do it right.

    In all the years I have been on this site, I don't think I've ever heard anyone be supportive of a home builder's project. I know there are a lot of people on here who feel that only professionals should design and build boats, but I reject that. To quote someone's signature, don't tell me not to do it, tell me how it can be done".
     

  15. cthippo
    Joined: Sep 2010
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    cthippo Senior Member

    Finally started chewing up some aluminum! These two assemblies are the rear of the cabin and the space between them will be the cabin door. I'm happy with the strength to weight ratio and rigidity of the gusseted aluminum construction. I intentionally overbuilt these a little as they will be right at deck level and so I'm adding some extra rigidity down low where the weight is a positive. Granted, it's only a couple of ounces, but still...

    Getting this far took about 100 rivets, so I ordered a box of 1000 and will pick up another hundred to get by until the box arrives next week. It's actually going considerably faster than i expected!
     

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