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Non hollow, hollow wooden board???

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  • Non hollow, hollow wooden board???

    After the second water intake, this time not due to forgotten valve, but due to a crack, I'm starting to think about a non hollow, hollow wooden surfboard.
    What do I mean with such a strange description?
    If I want to protect the inside of a board against water intake and the risk of moulding, I need to protect the interior surface with something, usually varnish or epoxy (maybe thinned), which is definitely not really ecofriendly.
    If I would build a HWS and fill the hollow inside with a PU foam, it would not be hollow anymore, this is the non hollow hollow wood... It may be not really ecofriendly anymore, but I could save wood and deckstrength and even reduce the outside glassing to a minimum. In total the non-ecofreiendliness could be more or less the same. I would not need a valve anymore, which would make the board even simplier. And due to reduced amount of epoxy and glass, less ribs and thinner wood, the final weight would be in the same region.
    And what is the advantage to a regular eps board? The 3D shape would be easier to create, because its given by the outline of the wooden frame.
    So my idea would be making a frame, make solid rails, glue either deck or bottom and then pour in the PU Foam. It would expand and fill all the gaps, the hollow nside, would not be hollow, the foam itself is waterproof and would not let any water in case of defects. Then the deckfoam would be cut and sanded down to the woodframe and finally the deck would be glued on. (or even glued directly using the foam, but this could be difficult and a mess too) (Another way could be gluing the deck and bottom onto the frame, foam from the sides and finally glue the rails on)
    Shaping and a thin hull of glass and epoxy to follow. Fin Blocks, Valves etc. not necessary anymore...
    Anybody build such a board already? What do you think about the idea. The only critical thing for me regards the ecofriendlyness, but since I always used epoxy in the past, it finally should not be a big difference
    The best surfer is the one with the biggest smile on his face...

  • #2
    Grant Newby has been vac bagging Paulownia onto EPS foam blanks and just oiling it. He has been doing this for years and lots of people do it now. Flama surf in Spain and others follow a similar process.
    Grants blog is a great spot to check out the latest ideas
    http://woodensurfboards.blogspot.fr/
    I have seen people glue foam between wooden frames and shape it, looks OK. I have seen someone try the expanding foam thing. Not a good idea. Very messy and doesn't sand well.

    As far as the holly grail of eco freindly board the Paulownia vac bagged onto EPS and oiled is hard to beat IF you can get localy grown Paulownia and EPS blanks produced near you which Grant can. If you are flying wood or anything from the other side of the world its not so eco anymore. You have to use what is locally availble to you.

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    • #3
      Its quite difficult to get Paulownia here..., just shelf planks for the local hardware store, with sometimes bad areas and glue joints, you have to rip them and put them together new...

      Of coarse the expanding foam can get messy, but the most important question is, whether its closed cell and "waterproof" or open cell and "spongy". If you would glue deck and bottom first and foam through the rail bands on each side, the mess could not be that much, you could just cut it even to the wood and glue the rails bands.

      Finally you could compensate the foam weight by using thinner wood for deck and bottom, which is easier to work with too, can use less ribs and if necessary less glass and epoxy. In the moment I do not build a board, I think, my next boeard could be done like that. If I would get decent paulownia in the meantime, I would think about the oil method too, but I assume I would stick to balsa or, since I could go thinner, try a cheap local wood, maybe larch or pine
      The best surfer is the one with the biggest smile on his face...

      Comment


      • #4
        Although not as satisfying as a proper wooden board it seems like the best compromise to make a board IMHO. Just depends on if you can get the recycled foam from Marco or any other wise ideas you might have. Josh Dowling used to make incredible boards before he had to quit due to epoxy sensitization.
        I really hate epoxy. Sensitive to heat, moisture, dust... melts in the heat. .. it's good to see a method without epoxy.

        Sunover make boards a bit like this. So does Firewire in their Timbertek. Before all this it was called Compsand. That should help you find out a lot more.

        I think 1.5lb EPS would be OK in this build method. I've tried 1.5lb in an epoxy only board and it was far too weak but with the wood it should be OK.

        I wonder how much weaker the boards are without epoxy? One aspect of epoxy I didn't manage to get right yet is the hard edges using a resin dam so bypassing all that would be great.

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        • #5
          I read about compsand already, you need vaccuum equipment, which I do ot want to buy. I think I will try, if I build a new board someday, building a very light frame, glue a thin deck and bottom and the fill it with the lightest PU expanding foam availlable from the openings at the railsides. Thee foam will expand and if I used too much, it will drain out at the rails. This will be cut away, the rails side evened out and the rails glued on. Depending on the wood, I would give it a light glass/epoxy hull, or a natural finish, no vent...
          The best surfer is the one with the biggest smile on his face...

          Comment


          • #6
            Funnily enough, I was thinking about the same thing today and came here to do some searching on expanding foam to see if anyone had done anything similar. The reason I thought of it was due to filling some large open fronted cavities in walls at work with expanding foam that will later be cut flush.

            The over spill 'blobs' are extremely light and the pushing force isn't horrendous if given a route to escape that's not too restrictive.

            The one time I remember seeing someone using expanding foam on a board was a completed board over at tree2sea and the board exploded - probably too much foam at once with too small of an escape hole. I think the idea of having the rail sides open and top and bottom on would work. Do the foam in stages with the board vertical. The excess that spills out the sides will slice off very easily.

            I would probably do it while standing on the tail not quite to the centre then flip it and do the same from the nose up. I think leaving the centre band until last would be the least risky to give it room to expand out.

            Apart from the eco side, what are the negatives?

            Also, would you definitely not need a vent?

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            • #7
              Originally posted by Stew View Post

              Also, would you definitely not need a vent?
              Difficult question, because the air is still in, but trapped within foam bubbles; and this may be comparable to a commercial board. And additionally foam is a good insulator, so even if the board is lying unprotected at a beach and the decks temperature start to rise, the inside temperatures will rise very slowly, the wood is an insulator too, so directly behind the woods the temperature will rise, but there is insulation too, heating up the entire room inside the foam is much more difficult than heating up the inside of a usual hollow board. It should be much more forgiving.

              I would cover it up after each surf, the longer its uncovered, the more dangerous it is. But regular boards usually do stand the heat and even compsands usually do not have any valves. And if the foam is airtight, a valve would not be of any use. Of course there is a risk, but I would like to try...
              And there are some real hollow wooden boards existing, without any valves and any problems at all. (If I remember T2S well...)

              When doing foam with open rails, you could also put some weights on the the board. So the pressure should relief to the rails side openings. Layer by layer working towards the outside...

              Other negative despite eco, I do not see, the foam should add stability, less ribs, wider rib spacing, thinner ribs, decks and bottoms, all should be possible, giving less wood, less weight, which will be compensated by the foams weight, better ding resistence, no water intake passible (if foam is waterproof), and/or thinner glass...

              Guess I will give it a try on my next winter project...
              The best surfer is the one with the biggest smile on his face...

              Comment


              • #8
                I've thought of this too, and have seen a few sites that have "eco friendly" pour foam. My idea was to build a normal fishbone frame board with the usual holes in the ribs to make it light, but make sure one set of holes line up from tail to nose near the stringer. Complete the board and somehow have an opening in either the tail or nose. Lets go with the tail and then drill a hole in the tail blocking the size a pipe, which is the length of the board. Take your pipe, run in down to the nose and then pour or maybe pump in the foam slowly bringing the pipe out. Mix the foam for the correct amount of space you are filling and it shouldn't blow your board out shape. Now after it has cured, put a plug in the tail where the hole was. It's a thought.

                Comment


                • #9
                  The HWS is flawed by the fact that you must make sure the plug is in when in the water, and out when not. My board sits on my closed in screen porch on my shaping stand and the other day my daughter noticed that the plug was not screwed all the way in. Not knowing what she was doing, she tightened it and left. I came home less than an hour later, and looked at the board, somethng wasn't right, it looked bloated, by just a little. It was very hot on the porch and I looked at the plug and freaked. When I loosened it, I swear it sounded like someone stuck a knife into a car tire, it was that loud and lasted 5-10 seconds. The board was Ok but it shows just how easy it is to ruin one in very little time.

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                  • #10
                    I have always used the goretex vented plugs and never had a problem. One of the first SUPs I made is sitting outside as decoration now, in direct sunlight for a lot of the day. It gets hot here in the summer too. It is still fine.
                    If using foam I would do a bit of research and make sure you use the right one. Some foam still gases, they make epoxy expanding foam for the marine industry that is waterproof and doesn't gas. It comes in different densities too. Not cheap though.
                    I saw a build where they built the frames etc as normal then just cut blocks of foam to fit between the frames. They were oversize then he just sanded back too the frames. It was just polystyrene foam from a hardware store. He then stuck the deck and bottom on as normal.

                    Comment


                    • #11
                      Originally posted by tarquin View Post
                      I have always used the goretex vented plugs and never had a problem. One of the first SUPs I made is sitting outside as decoration now, in direct sunlight for a lot of the day. It gets hot here in the summer too. It is still fine.
                      If using foam I would do a bit of research and make sure you use the right one. Some foam still gases, they make epoxy expanding foam for the marine industry that is waterproof and doesn't gas. It comes in different densities too. Not cheap though.
                      I saw a build where they built the frames etc as normal then just cut blocks of foam to fit between the frames. They were oversize then he just sanded back too the frames. It was just polystyrene foam from a hardware store. He then stuck the deck and bottom on as normal.
                      I'm thinking of converting mine. If it works, (I've heard conflicting stories) why does anyone use a normal plug? They are not cheap though...but if it works...

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                      • #12
                        i have recently built a foam core wakesurf board.i used the EPS foam i recycled from a flat screen tv carton. I rough shaped the blank and glued wood skins to the top and bottom. i glued it and set in the rocker jig. after drying it kept the shape perfectly. the skins are from a mix of species including cedar, pine, and maple.
                        EDIT: no vacuum bagging equipment was necessary

                        so far there has been zero need for venting, BUT, i havent ridden it yet, or left it in the sun for a long time, and it is a low volume very small thin board not meant for paddling so i cant say if eps core would be okay unvented on say an 8 footer

                        i have often thought about the gortex vents but it hurts to pay $25 for a 1" plastic bung. all my hollow boards to this date have used a brass 1/4"-20 insert, brass screw and rubber washer. they work perfectly as long as you remember to open them when you leave the water
                        Old enough to know better, young enough to do it anyway.

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