Shark bite in bow...help!

Discussion in 'Sunfish Talk' started by dougd, Sep 12, 2016.

Tags:
  1. mixmkr

    mixmkr Active Member

    Likes Received:
    70
    Trophy Points:
    28
    That's the best news. Anybody can do repairs but "life changing" on your own boat is tops!
     
    • Like Like x 2
  2. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    The trim is off. Seam looked OK except for one spot port side up near the bow handle. Looked to be a small split that I could press closed with finger pressure. I also snapped some pictures through the bow hole of the interior. The bow handle backing block looks metal to me. Is that expected?

    IMG_20160914_110344.jpg IMG_20160914_110357.jpg IMG_20160914_110709.jpg IMG_20160914_111010_hdr.jpg IMG_20160914_111019_hdr.jpg IMG_20160914_111027_hdr.jpg IMG_20160914_111215.jpg
     
  3. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    The deck doesn't show any damage to the gelcoat. You're off to a good start. :)

    That's been "the word" here on the later Sunfish. If there's been saltwater use, check it for corrosion, as you could certainly continue to use it. See if the screws back out without breaking off. I'd go up one screw size—in stainless steel of course.

    Over all, the interior looks well constructed! What is that thing that looks like a discarded snake skin? :confused:

    [​IMG]

    That small split could be the start of peeling back the deck. As you have seen, not everyone here is in agreement! :oops: Otherwise, the split is begging for epoxy resin to seal it shut.

    Your original photo showed a crack in the gelcoat (port side) that tells me that the hit was severe enough to consider something other than a "quick fix". The starboard side is somewhat worse. :( From what is shown in this photo—except for the rough condition of the bow handle and aluminum trim—this Sunfish looks like it's worth saving, for sure.

    Around here, the sailing season is shutting down, so a few weeks of decent Autumn weather would allow for a more extensive repair. If you repair from the inside, as suggested, consider a mix of fiberglass weaves. "Roving" is the coarsest—with "mat" used to take up space, as it has no real structure. Don't use mat. :confused: "Cloth" makes for a smooth, strong, finish, and is the only weave that is included in the $30 West Systems repair kit. If this wasn't such a relatively small area, I'd consider locating a "chopper gun" to start a repair of the inside. Cool fiberglass "spray" tool, but became outmoded with rises in oil prices.

    [​IMG]

    Cracked gelcoat—port and starboard:

    [​IMG] [​IMG]
    Anyone else here reminded of the huge, but harmless, Basking Shark of the North Atlantic? An adult Basking Shark is nearly three times the length of a Sunfish!


    [​IMG]

    :eek:
     
  4. Webfoot1

    Webfoot1 Active Member

    Likes Received:
    37
    Trophy Points:
    28
    Yep, the split is the deck/hull seam. Sunfish split apart on their own without any help, a lot! If you are going to seal the split you have to widen/lengthen the split first to get a layer of mat and epoxy in the seam.
    If you are going to open her up, well, you've be given a place to start. Generally we always work with mat under cloth as the mat keeps the cloth from cracking. So, for three layers to about equal the thickness to the hull we go mat/cloth mat/cloth mat/cloth. I think the woven roving used by the factory is so they can lay it in the mold and get the air bubbles out. Not usually used for repairs. Those spider webs in the are a good indication that the underlying fiberglass is compromised farther back than the edge the hole. I'm not seeing a good candidate for a backer patch but other with a wider skill set then me might. Lots of good suggestions on which way to go,
    at this point I this the easiest way to go is to stabilize the damaged area first with three layers of mat cloth laid up behind the damaged area extending past the spider cracks. It will give you a stable base to start grinding back the gel-coat around the damaged area. By making the repair from the inside you've basically completed the structural phase and the rest of the outside work will be cosmetic. The final filler coats should let you reshape the bow back to factory contour. Not uncommon damage for a Sunfish, happens a lot. If your trailer did this get one of those big rubber V bow stopper blocks, I use them on all my trailers.
     
  5. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    Well, we're in it now! I split the deck. Starboard side went great, port side not so much. It started splitting too high, into the deck layer. I had to saw down a bit to correct. Very damp inside. The yellow foam is saturated.

    IMG_20160915_162444.jpg IMG_20160915_162418.jpg IMG_20160915_162409.jpg
     
  6. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    No posts today? :oops:

    We can't have that! :confused:
    ________________________________

    Edit: I see dougd has logged in while I was typing. :confused: :( Not to worry...
    ________________________________


    OK, there wasn't a general approval of my suggestion for a transplant from a "donor" Sunfish so :( how about this?

    Widen the existing seam-split at the deck back about 10-inches. Do both sides, and leave the deck alone for now.

    Take a Sawzall, and, under the deck, cut the bow section completely off. :eek: Trim the damaged bow back to where it's solid again. Repair the piece from the inside as above, using a sandblaster to completely roughen the inside's original (and uneven) roving fiberglass material. Build up layers inside of mat/cloth mat/cloth mat/cloth—as above. Be generous with repairing the keel area of both sections—bow and hull. Replace the bow handle. Foam-in the part of the Styrofoam blocks that can be reached.

    Optional: Bolts (with washers) can be used at this point, with the head epoxied inside. The threads can be measured for an "acorn" nut outside. This, in those cases (like mine) that the Sunfish's weight is carried by the bow handle.

    Remove the snake skin. ;)

    Go find another Sunfish, and sculpt your bow section's outside dimensions to the contours of an original Sunfish bow. Sand inside and outside back about three inches, tapering the margins to paper-thin. Roughen-up the deck's contact areas. Use the batten/stir-stick technique on both sections to align the new bow to the hull. Align deck and "refurbished" bow section, tap into place, borrow extra clamps and epoxy forever. Sand and paint—add gelcoat if you must have it. :rolleyes:

    Woe to befall any dock this repaired Sunfish might hit! ;)
     
    Last edited: Sep 15, 2016
  7. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    You're still logged-in at 5:48. So there is some good news here. Access is easy now!
     
  8. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    It seems like I'll need much more than what comes in the West System repair kit. What's a good place to buy these supplies (epoxy, resin, fiberglass, etc.)? No marine stores nearby.
     
  9. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    I'm presently in rural New Hampshire, so I go to my local True Value hardware $tore.

    Not much left of a $100 bill! :eek:
     
  10. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    I found a local hardware store just down the way that is a West System dealer according to their website. I'll head over tomorrow and see what that have.
     
  11. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    The "snake skin" looks and feels deliberate. Possibly some kind of handle, maybe from the original manufacturing process?
     
  12. Webfoot1

    Webfoot1 Active Member

    Likes Received:
    37
    Trophy Points:
    28
    There was a thread on here a few years back about fixing the same kind of damage. The original poster went with molding a new
    bow piece off his other Sunfish. There are some pics on this site somewhere. Anywho, the first copy you make off the good Sunfish will be the mold
    for the final product. The mold is slightly bigger than what you are copying. You can make the mold out of plaster and use Vaseline
    as the release agent. The plaster mold will be for one-time use. After removing the mold from the good Sunfish you can lay-up fiberglass
    inside the mold. This will result in a original size duplication of the bow. You can use release agent or break the mold apart when you are done. Oh, I forgot to say that if making a mold you have to remove the trim strip from the copy boat so you can mold the flange.

    West Epoxy with 206 Slow Hardener seems to work good. Micro Balloons seem to be a good all purpose
    filler.
     
    Last edited: Sep 15, 2016
  13. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    A Sunfish that is very damp inside? :eek: Never happens! ;)

    Is the yellow foam saturated to the point that it feels like a sponge? "Saturation" takes a long time to happen—and to undo—so what you're seeing may be the result of that one-time bow damage. Open ports, if you have any. Using the highest setting, set a small fan off to one side so the damp air runs a circuit to return the bad air back out the opening.

    Molding the bow with plaster:

    repair ? | SailingForums.com

    A search is MUCH easier if the title includes something that refers to the exact repair. :rolleyes:

    I liked the alternative mentioned of using Great Stuff :)

    If you go the plaster-mold route, press a layer of [galvanized] hardware-cloth into the soft plaster to keep the mold from breaking apart while you're working with it.:confused:

    [​IMG]
     
    Last edited: Sep 16, 2016
  14. andyatos

    andyatos Active Member

    Likes Received:
    116
    Trophy Points:
    43
    That is very interesting. Because when I opened up the deck from the hull at the bow to do some repairs on my Sunfish, I found the exact same "snake skin" loop of glass. I thought it was some kind of half assed job from the previous owner but now I'm thinking otherwise. Anyone know what this loop of glass if for?

    - Andy
     
  15. Webfoot1

    Webfoot1 Active Member

    Likes Received:
    37
    Trophy Points:
    28
    Sure do, the loop is so the factory can pull the hull from the mold.
     
    • Like Like x 1
  16. dougd

    dougd New Member

    Likes Received:
    0
    Trophy Points:
    1
    On the cloth/mat suggestion, I am reading that epoxy doesn't play well with csm on curved surfaces. Should I be using poly resin or a combination of poly and epoxy in different locations? I had sold myself on epoxy because of the reported superior strength and bonding. So, where to find a sunfish to make a bow mold?
     
  17. mixmkr

    mixmkr Active Member

    Likes Received:
    70
    Trophy Points:
    28
    I wouldn't mix poly and epoxy. Use one or the other. As far as a mold for repair...if the front foot or more of the bow was missing, a mold might be helpful. With the size repair you have, I don't see a problem guestimating the original, as you have enough there to still give you a good idea. As mentioned previously, making the strength on the inside, now the boat is open and then extra glass layers on the outside and fair it out smooth.

    On the topic of strength, although epoxy resin has better bonding than polyester, the resin itself is not the "strength" but instead the fiberglass cloth and how it is laid and applied. As I mentioned previously as well, bonding can be more than sufficient with polyester, if the surfaces are correctly repaired.... sanded well and clean. A good mechanical bond will be basically impossible to rip apart.

    I only suggested poly previously, mainly on the basis of seeing too many failures of gelcoat applied over "unprepared" West System finishes. West System creates a "blush" that CANNOT be sanded off completely (unless you remove a lot of product!), but must be scrubbed of sufficiently with soap and water. If you're painting, a good primer and paint, ..the decision is less important which you use.
     
  18. Light and Variable Winds

    Light and Variable Winds Well-Known Member

    Likes Received:
    138
    Trophy Points:
    63
    A nearby city should have a yacht club who should be able to find a cooperative Sunfish owner or three. A half-day rental? A neighbor? A free Sunfish from Craigslist? Advertise for one—"Wanted". Craigslist ads are free, and there's always somebody around who's storing one and would like to have the space. Familiarize yourself with "clones", some of which have identical hulls. (Viking, AMFlite, List).

    Especially as I have two spare Sunfish handy, I would attempt a bow mold. But it sounds like West Systems epoxy + micro balloons would require less effort. (And no mold needed).

    1) Epoxy should be able to do the whole job. The main disadvantage with epoxy is that unless you do many minutes of layering all at once, each layer has to be sanded after curing.

    2) Did the gelcoat of the top of the deck turn out OK? IIRC, Webfoot1 says new gelcoat doesn't work well on epoxy.
     
  19. Webfoot1

    Webfoot1 Active Member

    Likes Received:
    37
    Trophy Points:
    28
    Well that's interesting, can you post a link or location of the article. Molding a bow would in effect be working
    on the same curved surface. If I remember correctly epoxy has a bond strength 20% greater than polyester. I can
    attest that West epoxy does work very well from using it over the years. There is a endless argument that always
    pops up over which is better, poly or epoxy. Personally, I think it comes down to personal preference with one argument
    being that that is what was used to make the boat and another that epoxy has greater bond strength. By "play well" I'm not
    sure they mean bonding to a curved surface or getting the cloth/mat to work its self around the surface. For the inside
    of the bow I know the cloth will deform enough to cover the compound surface without problem. If you can't work it
    flat the use of slow cure hardener gives you more than enough time remove the mat/cloth and go with plan B. The weight
    of the cloth you use is also going to make a difference in how well it forms. I've never heard of anyone using a combination
    of poly and epoxy.

    There is nothing wrong with molding a new bow but I think going this route for the amount of damage you have increases
    the complexity and difficulty of the repair. I have Sunfish I could try and make a fiberglass mold from it you go this route. Basically
    I would be doing on the outside what you would be doing on the inside. I can see where the complex shape might force
    me to go with multiple pieces of fiberglass and then use filler to smooth the inside of the mold. The advantage of working
    inside the bow is it does not have to look pretty, just be a solid repair. You're not laying up into the keel section which would
    greatly complicate the compound curve. What I'm trying to aim for is to give you the simplest method of repair that pretty much
    gives a goof-proof result.

    Hum, I'm thinking you need something for a confidence builder before you tackle this. Do you have anything you could use to
    practice laying up fiberglass that you don't care about, say like a Styrofoam ice chest like the cheep kind they sell at stores. This
    would give you flat surfaces and curves to do some layout on. Sort of get a feel for how well you can bend the mat/cloth before
    it will not lay flat. Craft stores sell Styrofoam shapes like cones, spheres, torus/donut etc.

    I'm going to get hit for this but I really have good luck with West-Epoxy and 206 Hardener. I have a can of poly I've
    never used so maybe I'll have to break it out and give it a try. Get a bag of cloth and a bag of mat and it will last for
    years over many projects. To totally digress, I plugged a hole in a air-tank by coating cloth with J.B. weld to make
    a patch, pretty dumb huh?

    Generally, fiberglass filler covers the epoxy before the gel coat is applied doing repairs. I
    really don't have enough experience to say what happens to gel-coat directly over
    epoxy. My attempt with brushing on gel-coat was not a happy one but then I learned
    that gel-coat has a shelf life of only one year and purchasing it at West-Marine might
    not have been such a good decision.
     
    Last edited: Sep 16, 2016
  20. Sailflow

    Sailflow Member

    Likes Received:
    6
    Trophy Points:
    8
    That was a minor repair, a couple layers of glass, dry time. Some marine tex after the glass. Some sanding with a block and you would have the bow shaped back to original. Splitting just adds another variable.

    No need to mold.
     

Share This Page