Newbie question regarding choosing a core material and type of glass

Discussion in 'Materials' started by Santana35, May 31, 2020.

  1. Santana35
    Joined: May 2020
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    Location: Half Moon Bay California

    Santana35 New Member

    I’ve lurked long enough and decided to venture the query for suggestions I am needing help with

    ______Background first

    Santana 35
    Sailed and lived on it for most of the last 5 years
    Recently gutted the interior front half

    Purchased the boat 10 years ago and the prior keel stiffening completed left several shallow “bilge” areas about 3 inches deep that I intend to fill in and making the floor flat and solid back to the engine compartment.

    I also want to install two watertight bulkheads
    Constructing a chain locker for two anchors in the bow
    And a second bulkhead further back separating the sail storage area from the living area.

    The triangular shaped bulkhead at anchor locker will be less than 4 square feet
    30 inches wide at the underside of the deck and 36 inches at the tallest.
    Obviously taking abuse from chain.

    The second bulkhead dividing the sail storage and living area is approximately 27 square feet
    80 inches wide at the underside of the deck and 72 inches at the tallest


    Questions I have been procrastinating on

    1 What to use to fill in the shallow “bilge” areas. Approximately 24 inches wide and 14 inches across and 3 inches deep.
    Several layups of core material between layers of fabric or low density filler mixture with epoxy and hardener.

    2 Core material and choice of fabric and layup for the watertight bulkheads. I’ve been extremely indecisive regarding core material versus solid glass even.
     
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Welcome to the Forum Santana.
    For those (like me) who are not familiar with the Santana 35, here is some basic background info, including a general arrangement drawing.
    https://sailboatdata.com/sailboat/santana-35

    The drawing shows an anchor locker bulkhead up forward, and another two (non water-tight - they have access through them) bulkheads a bit further back, on the forward and aft side of the heads.
    Are your bulkheads in the same locations? I am guessing that your 'new' aft bulkhead is / will be on the forward side of the heads?

    Re the shallow bilge area, could you post a photo or two showing this area please?
    Do you want to make it 'smooth' so that you do not have small puddles of water collecting in the 3" deep areas?
    Do you have an existing bilge sump where (most of) the water can drain to?
    If not, and you have to sponge dry your bilges, I would be inclined to leave the 3" deep areas alone, unless by filling them in you will be significantly adding useful strength locally.
     
  3. Santana35
    Joined: May 2020
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    Location: Half Moon Bay California

    Santana35 New Member

    Thank you for the swift response

    I am still trying to figure out how to post photos.
    I have many from since I started working on it.

    The most forward bulkhead that defined the anchor locker was a piece of 1/2” plywood with some meager tabbing around the perimeter attaching it to the hull and deck.
    Huge opening thru but NO deck access so I refused to think of it as an anchor locker.
    Can’t see anyone electing to retrieve the anchor chain from the bow, lugging it across deck and after going below taking if back forward and stowing it in the bow

    What I believe you are referring to as the additional forward bulkheads were small hanging closets on both port and starboard that went from the underside of the deck down to the interior fiberglass formed from the male plug. They too were installed with meager tabbing. The second bulkhead, defining the aft side of the head was 3/8” teak plywood. Again, minimal tabbing installed. Two partitions port and starboard with a hinged door for privacy.

    The pockets that remain after the keel reinforcement are far more tedious and nasty to deal with than sponge drying the entire boat.
    There is ample slope bow to stern and the continuous floor will allow collection in the rear bilge area.
    My intent is to have the entire interior including the minimal cabinetry either gel coat or catalyzed paint or fabricated from plastics, and the ability to remove any upholstery/cushions/bedding and hose down the entire interior


    Won’t start the back half of the project until the front half is complete. I am still living aboard with a plastic sheeting partition separating the two.
     

    Attached Files:

  4. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Whomever did the repair forgot to cut limber holes. What do they have as a core? It would be simplest to drill limber holes for the water to flow aft.
     
  5. Santana35
    Joined: May 2020
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    Location: Half Moon Bay California

    Santana35 New Member

    Thank you for joining in the conversation Gonzo.

    There is a single limber hole in one of the ribs. Its useless for the most part.
    Few years ago I faired and coated the inside of each compartment to aid in cleaning but I have decided to move forward with leveling the sole in the forward half of the boat.
    Frustration level was bad enough that on more than one occasion I came close to mixing up a few gallons of resin and filler to a peanut butter consistency and dumping it in.

    I usually prescribe to the KISS attitude but usually in regards to attempting to avoid making things complicated but this is not one of those times. I’m not looking for shortcuts, or a way of getting out of work or expense.
    I know I want a flat sole for the front half of the boat.
    Will create a better sump area at the engine compartment with a better bilge setup for keeping things dry and emergencies.

    I don’t have the experience to feel I would be accurate in determining the material they used.
    Attached are some photos.
    The closeups are the aft “rib” that seperated the largest sump/bilge compartment and the adjacent smaller one.
    It appears to be a resin/hardener and filler mixture like West 403 or 404
    Longitudinally, the “grid” stiffening running fore and aft was mostly hollow and formed into the interior mold and attached to the hull in a disappointing manner. Lots of voids, globs, wood that had moisture in most areas and was rotten.
    I was considering adding more ribs similar to what is there now, before filling in the voids.

    Thanks again for your input.
     

    Attached Files:

  6. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Easiest way to install limbers now is with an oscillating tool. Drilling them is harder.

    Please slow down. Mixing up a big batch of epoxy with fillers might just burn the boat to the ground.

    When you take pictures, you need to take them from further away and explain them a bit better. I, for one, am a bit lost as to what you have planned here.

    The first thing that is required is the removal of all wet components. There may be some pushback here, but you must do it first. There is no reason to leave any rot. The next thing to do is take photos and mark them up on a computer or smartphone and explain the plan a bit better. Many of us here are capable of helping you fix it. Some more than others for structural work. I don't like giving structural advice.
     
  7. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    For a sole, first determine if the bilge is wet or dry. If the bilge is a wet bilge, you must install limbers. If they go through wood, you must isolate the limber from wood. This can be done by overcutting with an oscillating tool, and installing a half pipe of pvc and gluing it in with epoxy and filling over the top and the bottom to encapsulate all wood.

    Then, once the bilge is ready for any possible water, you can install the sole. The sole could be made from just about any core and the spans will determine the thickness. Spans of say 16" can be managed with 12mm cores with thickish skins on each side. For larger spans, you'll want either 20mm core or full inch cores. You would dryfit and then glass the core on the bottom and top. Then you verify the fit and then bond it down with thixo of cabosil and resin with some weights.

    Your bulkhead work is similar. Dryfit bulkheads using 12,20 or 25 mm cores. A 12mm core is plenty. After dryfitting them, you will need to glass them off the boat. The chain locker base could be made from a higher density core. I would glass it with at least 25 ounces of glass on the top and probably the same on the bottom; depends on weights. A good HD core can be purchased and you would want a 26 pound density I'd say. The 12mm foam cores could be cut into edge cleats for the base of the chain locker as well. An edge cleat is a way to support the base. This way, you apply two edge cleats to the sides of the hull and glass tape them in. Then you glue on the base and glass tape the two top sides. Then you install the crash bulkhead as best you can. One problem with your plan is you will not have access to the back side of these bulkheads for taping. That is not an issue except for the chain locker. The chain locker must be taped inside or it will leak. You can use tapes on the accessible side only.

    The sail locker will be similar. The other option will be to cut an access panel into the lockers that you can fit into the do the taping.

    12 mm core would work well..heavier core for the chain base...

    I gotta go sand!!!
     
  8. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    S35

    Your boat was factory built in the racing set up. The factory left a few items off in order to keep it as light as possible.

    The cruising model has a has hole and provisions for an anchor winch.
    Opposite of the hanging locker would have been a head complete with s shower sump separate from the wet bilge. There should be a wood grate over the holes in the sole.

    The pitiful tabbing is typically of production boats.
     
  9. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    If you only need to fill the holes, blue/pink styrofoam with a couple of 10 oz layers of fiberglass cloth should do the trick.
     
  10. Santana35
    Joined: May 2020
    Posts: 4
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    Location: Half Moon Bay California

    Santana35 New Member

    Thank you to all of you for your input. It’s direction and info I sincerely appreciate and needed.

    If any of you have opinions or thoughts they care to throw at me regarding a retractable bowsprit I’m all ears.
    90 percent of my sailing is single handed and I drool over the simplicity of handling A Symmetricals with them.

    Having started all this work, I figure now is the time to do any and all of it.
    I already fabricated an anchor roller setup a few years ago as the boat had nothing before.

    I know some changes I intend to make to it when I build the anchor locker.
    I can divide the locker in two with the bowsprit in the middle under the deck or I can have it on one side or the other. Curious of the opinions from some of you and thanks again.
     
    Last edited: Jun 3, 2020

  11. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    You need to think through the build steps.

    Is the sail locker underneath?

    And why two bulkheads? Is it to protect the sails in a crash?

    Is the anchor locker above the sail locker?

    I think you are not getting a ton of replies because people are just a bit confused about the plan.

    I don't know diddly about a retractable bowsprit, but all you need to know about building I can help with.
     
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