Plywood designs as foam core and fiberglass

Discussion in 'Boat Design' started by LazyFox, Jul 14, 2021.

  1. Scuff
    Joined: Nov 2016
    Posts: 145
    Likes: 20, Points: 18, Legacy Rep: 10
    Location: Richmond VA

    Scuff Senior Member

    I am going to use foam. You need to check your ama patterns (frames 1 and 2 on mine) if your doing the plumb bow. My 27-9 were not updated and I found someone else who indicated that their plans for the 24' boat weren't updated either. Very cool your building one too I think it's a very good cruising design I did stretch mine by 1' because my shop would accommodate it. Are you building the XR version?
     
  2. rberrey
    Joined: Oct 2010
    Posts: 456
    Likes: 20, Points: 18, Legacy Rep: 112
    Location: AL gulf coast

    rberrey Senior Member

    Scuff , the weight savings is about where I was at , I bought 17 oz biax and 18 oz uni for the outside hull , 12ox biax and 18 0z uni inside . I planned on more lay ups below the water line and bought 6 oz S glass for the outside finished layer , still would have been weight savings and epoxy savings with no mat to suck it up . He had me go with 5/8 H 80 instead of the 1/2 on the study plans . Nice picture , I'm a little jealous . I bought 2 Anderson #10 standard winches , then bought 6 #10,s with handles from a guy who was going to build an ice boat . When you get to the point you are shopping for winches and want one or two #10,s let me know , I will give yo a 1/2 price deal , I might let one hatch go as well .
     
  3. rberrey
    Joined: Oct 2010
    Posts: 456
    Likes: 20, Points: 18, Legacy Rep: 112
    Location: AL gulf coast

    rberrey Senior Member

    Scuff , I'm not building the 31 anymore , will find another boat to build later .
     
  4. LazyFox
    Joined: Jul 2021
    Posts: 6
    Likes: 1, Points: 3
    Location: Texas

    LazyFox Junior Member

    Thanks guys, I really appreciate the responses. I didn't know where to start looking when it came to material swaps, and you've given me a lot to work with. All I managed to find was a bunch of people basically saying that if it's done wrong I would regret it, and the boat would be trash. Like @fallguy said, I'm probably just going to suck it up and bite the bullet when it comes to the plywood costs. I was hoping I would find a way to trade material costs for labor, but it doesn't look like that's going to be the case. I Live in west Texas so sourcing marine grade plywood locally is practically impossible. Does anyone recommend an online supplier they have personally dealt with?
     
  5. rberrey
    Joined: Oct 2010
    Posts: 456
    Likes: 20, Points: 18, Legacy Rep: 112
    Location: AL gulf coast

    rberrey Senior Member

    Replacing ply with foam is not a big deal . Boat Builder Central ( Bateau ) sells marine ply , if you buy your material from them they will help you with advice . Fiberglass Supply in Wa. ( Water Tank Rd. ) has good service and you can price your boat material out . They have case price on foam and did better than case price for me . Keep in mind that if you need 45 sheets of foam or wood you will always need one more , furniture ect.
    1/2" 5/8" 3/4 "
    Okoume ply per sheet 9 9 11
    " " " weight 37 lb 44lb 52lb
    Merranti ply per sheet 9 11 13
    " " " weight 45 60 70
    Russian Birch ply per 9 11 13 has the same water proof glue as marine , heaver and bullet proof
    "' " weight 82 lbs
    Ask Fiberglass Supply if they can source Douglas Fir ply , but if you can't drive to pick up your ply shipping will eat you up . Find a building supply company that orders concrete form ply , their supplier should be able to source marine ply as well , buy an extra sheet or two . I would price out the foam for the hull and deck if I were you .
     
  6. fallguy
    Joined: Dec 2016
    Posts: 4,628
    Likes: 821, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Jeff or Reid at BBC in Florida.

    west Texas where?
     
  7. LazyFox
    Joined: Jul 2021
    Posts: 6
    Likes: 1, Points: 3
    Location: Texas

    LazyFox Junior Member

    The Lubbock area unfortunately, and as the foreman of an on-call crew I can't exactly just take off to go get materials either.
     
  8. LazyFox
    Joined: Jul 2021
    Posts: 6
    Likes: 1, Points: 3
    Location: Texas

    LazyFox Junior Member

    According to the materials list I'm looking at 18 sheets of 9mm, 29 sheets of 6mm, and 7 sheets of 4mm.
     
  9. bajansailor
    Joined: Oct 2007
    Posts: 2,049
    Likes: 675, Points: 113, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    I am just wondering what you find particularly appealing about the Wharram Tiki 30, in comparison to plans for other 30' catamarans that are also available?
    Here is a link to her -
    Tiki 30 | James Wharram Designs https://www.wharram.com/gallery/tiki-designs/tiki30

    Richard Woods' 30' catamaran Windsong is similar in some ways to the Tiki 30 (I think that Richard originally worked for Wharram, before setting up on his own), and it is possible to buy plans for building her with fibreglass flat panels instead of plywood.
    Sailing Catamarans - Windsong - 9m deep V hull ocean cruiser https://sailingcatamarans.com/index.php/designs-2/3-25ft-to-30ft-catamarans-designs/174-windsong

    There is also the 32' Woods Eclipse, designed for foam sandwich construction - this would be my favourite by far if I was comparing her to the Tiki 30.
    Sailing Catamarans - Eclipse - 9.9m performance cruiser https://sailingcatamarans.com/index.php/designs-2/5-catamarans-over-40ft/184-eclipse
     
    fallguy likes this.
  10. LazyFox
    Joined: Jul 2021
    Posts: 6
    Likes: 1, Points: 3
    Location: Texas

    LazyFox Junior Member

    Basically build cost, final weight, and the fact that the tiki can be broken down and put on a trailer. Being 500 miles from the coast, transportation of the final build will be something I have to take into consideration. Being able to tow the boat with the vehicle I already have makes the choice easier to make in favor of the Tiki.
     
    bajansailor likes this.
  11. gonzo
    Joined: Aug 2002
    Posts: 15,250
    Likes: 951, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Would you be willing to give him a written guarantee that your foam replacement laminate will work?
     
  12. fallguy
    Joined: Dec 2016
    Posts: 4,628
    Likes: 821, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    But you also built in a female jig. This is important to note that foam if built over a male must be flipped with jig still in and then bulkheads are added while jog sections are moved one at a time.

    Also, meaning like mine..
     
  13. Scuff
    Joined: Nov 2016
    Posts: 145
    Likes: 20, Points: 18, Legacy Rep: 10
    Location: Richmond VA

    Scuff Senior Member

    No built on a male mold .. you did flat panel on a table and then assembled I thought? I used my car lift to pick the hull up off of the mold.
    1. Add stringers at sheer and stretchers. 2. Lift hull off of mold and disassemble mold stringers as you lift it. 3. Once high enough remove remaining stringers and frames. 4. Lower hull to floor. 5. Use one side of the lift with preventers and struts to roll the hull over. 6. Once upright and on the cradles do the last of the prep and then glass it.
     
    Last edited: Jul 16, 2021
  14. rberrey
    Joined: Oct 2010
    Posts: 456
    Likes: 20, Points: 18, Legacy Rep: 112
    Location: AL gulf coast

    rberrey Senior Member

    Gonzo , I'm not giving him a replacement laminate , he can do the math for himself , the information to do that is all over the web . No matter what material used on a boat build or any other construction project , it has to meet the requirements of the designer . If a designer has 1/2" ply listed then 3/4" foam will meet the same specs core wise with the proper laminate . You can find build treads with much faster and exotic catamarans being built with triax or x numbers of biax , it is no big deal to back check the laminate schedule you come up with to those of comparable boats . And as Fallguy can tell you if you buy your material from BBC they they will be more than willing to help him .
     

  15. fallguy
    Joined: Dec 2016
    Posts: 4,628
    Likes: 821, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Honestly, you oversimplified. Even a foam laminate requires higher density inserts at hardware locations.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.