Another Johnsen Rebuild *Questions*

Discussion in 'Boat Yard Basics' started by Eric_Greenstein, Nov 18, 2014.

  1. Eric_Greenstein

    Eric_Greenstein I Love!

    Ok, so ive been looking for a cheap boat to work on during my slow season.  I found a 15 (14'11") with title and trailer for 320 bucks.  Figured the title was worth that much so I grabbed it.  So far ive nearly gutted it and removed all kinds of wet foam and rotten wood.  Blah blah, you see the pic. I would like to keep it as light as possible to help draft.  I would like to add a front and rear deck as well as a slightly raised floor.  Not sure about gunnels yet...

    Question 1
    Please share your honest opinions of this boat.  I plan to use it for backwater creeks and mostly protected areas.  Is the hull slap any worse then say a gheenoe or carolina skiff? 

    Question 2
    I know there are many helpful rebuild threads out there but I can't find any that list the amount of materials used.  I plan on using plywood from lowes because there are no marine plywood suppliers in my area (Daytona).  I need to order my epoxy resin, glass, and fillers. I plan on using MarinePoxy.  Any help with what and how much to order would be greatly appreciated. 

    Thanks in advanced
  2. tomahawk

    tomahawk Well-Known Member

    Take a short ride down to Vero Beach and get the ply from here:

    Order online and check the pickup in person box. Good tech support on their forum as well for their materials.

    If you want it to last and be light don't use ply from Lowes. The cost of the wood will be a small portion of the overall cost of the project and saving a hundred or so on plywood isn't really cost effective in the long run.

  3. cutrunner

    cutrunner Cert. Yamaha technician

    ^ this
    or dont use wood.
    a sheet of nidacore costs the same or less than a sheet of ply and is MUCH lighter
    that boat will weigh a ton if you did wood decks, bulkheads, floor and gunnels
    i know, ive done it. To be fair i did overbuild but my point stil stands
  4. cutrunner

    cutrunner Cert. Yamaha technician

    Also if you go with nidacore you can go to polyester resin and save money over the epoxy
  5. Eric_Greenstein

    Eric_Greenstein I Love!

    Im leaning towards 3.8 or 1/2 marine ply. Everything I have read about nida core is either confusing or bad.
  6. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

    Purchased from Boat Builder Central (Bateau)
    disclaimer I could not find my receipts so these are estimates
    1 sheet of 3/4" marine ply on transom.
    2 sheets of 3/8' for front & rear decks and extended gunnels to avg 10.5 inches.
    40' of 1"x4" cypress for cleats and supports.
    6 gals of marine epoxy included painting 2 boats and 2 canoes with graphite epoxy mix ( 1 pound Graphite)
    5 lbs wood flour to make fillets and fill
    1-1/2 qts Quick Fair
    1 gal Epoxy primer
    5 yards of 10 oz cloth to cover decks, 1 layer on transom and 1 layer on gunnels.
    80 yards of 6" tape to tab and strenthen gunnels
    A couple yards of 1708 for transom and build livewell.
    I did not build a false floor in mine but if I did I would probably use a composite. :)
  7. DuckNut

    DuckNut Brandon, FL

    Leakin hit it spot on - and while you are at Bateau buying your wood, get the rest of your supplies at Raka

    Don't know the city but website will get you there -
  8. Eric_Greenstein

    Eric_Greenstein I Love!

    Thanks for the list Leana. I was hoping to do it with 3-4 sheets of 3/8. Just a few questions.
    1.Did you really use nearly a full sheet of 3/4 on the transom? Seems like a ton of weight?
    2.Could you explain the graphite epoxy mix thing? I was hoping I could do everything you did along with false floor with the 6 gallon marinepoxy kit.
    3.Lastly and most importantly, are you happy with the boats performance now? Any pics?
  9. tomahawk

    tomahawk Well-Known Member

    Raka is in Ft. Pierce, a little south of Vero, FG Supply in north Ft. Pierce sells it for the same price. Its just a couple of miles from BBC.
    I used mostly Marinepoxy from BBC on my build and was really happy with it. I used some Raka UV resistant on my CF grab bar. It was really nice and looks great.
  10. Eric_Greenstein

    Eric_Greenstein I Love!

    Got the wood off the transom today, that was a job!
  11. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

    There are alot of more knowledgeable posters on here and they have helped alot of people. If you want to read up on things before you ask I gave you some links below.
    1. No I did not use the full sheet, two layers of 3/4" plywood epoxy coated and then glued together with epoxy/ wood flour mix.
    2.Graphite epoxy coat
    (This is a real dark black shiney finish, if I was to do it again I might have gone with gelcoat, I camp for several weeks on islands every year, but the graphite/ epoxy mix is just like rolling on an oil base)
    Here is their page on basic boat building techiques
    3. Yes it does well with a 25 Yamaha 2 stroke.  Trim tabs help in chop and keeping down spray. Removing one of the 2 boxes in center of boat really opened it up. It serves well for the flats, shrimping and some gigging.
    P.M. me if you want to see it  :cool:
  12. Backwater

    Backwater Fly Fishing Shaman

    Had the same hull once and can tell you it's a much better ride that a carolina skiff or a gheenoe.  Take a look at a 15ft Dolphin.  Hull has a similar design.

    The 1st time I saw the 1st Hellsbay at a show where Flip was talking it up, I thought, that's a lot of dough for an over -glorified Johnsen skiff.  lol  Also, take a look at the lines of an Arkona Native.  Looks like a 16ft Johnsen with the rear hull extended a ft.   ;)

    I would stay away from making it too heavy. That boat doesn't like to sport too much weight.   If you must use plywood, then use 1/2 fur plywood only and glass both sides.  Fur is lighter and stiffer than marine plywood (and cheaper) and is plenty strong enough when glassed on both sides and properly mounted, supported and tabbed in good.  But I like the idea to use a foam board or nitacore for the decks and mods, then glass top and bottom using 1708 or 1808.

    Transom?   Go with 3 layers of 1/2" fur plywood (about 1 - 4'x8' sheet) and glass in all layers, one at a time.  I would also use at least 1 layer of woven roven (still wet) inside the transom skin before installing the new transom layers.  Make sure it is fully and completely braced with good pressure to the original transom skin to bond properly and reduce air pockets.  The layers can be installed in 1 build-out and braced without the final glass layer on the outside of the last board, so that the braces can be affixed and used.  Once it kicks and cures, then the final layer can be installed, wetted out and rolled.

    I would install at least 2 main stringers (can use foam board and glass it in) and tab those into the transom.  On top of those stringers, I would glass in knees on top of the stringers to the transom. I would take a final glass layer on the transom 2 feet down the inside of both freeboards and 2 feet down the inside bottom before installing the stringers and knees.  I highly recommend glassing in a couple of strips of wide fiberglass tape down the full length of the keel and one each down each chine. Consider adding a full layer of 1708 down the entire bottom of the boat before installing the stringers.  Those boats were built thin.  Remember to grind off all gelcoat to green glass to get a good bond.

    Make sure any hole that is drilled in the transom is drilled oversize and then use epoxy resin to coat the inside of the holes, using several coats.  Then 5200 any and all thu-hull bolts. That's the #1 place where wood rot creep starts.

    Good luck and have fun.

    Btw, for anyone out there who's interested, I might have a hull just like that for about the same price, gutted and ready for a build-up.  I just don't have the time and have a complicated project skiff ahead of it.  So I might be I'm willing to part with it for the right price.

    PM me if interested.
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