Repairing a crack in the mast step

Discussion in 'Sunfish Talk' started by paddywagon, Sep 7, 2016.

  1. paddywagon

    paddywagon New Member

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    Hi all,
    Over the last year I've been fixing up the beautiful old sunfish that I bought(best guess I have is 1970 from the serial number 80853 and lack of an expanded cockpit). I just got around to doing a leak test and have determined the water I keep finding in the boat is coming from the mast step, which has a crack running vertically for about 4 inches. It looks like some pieces of the fiberglass has fallen away too. My question is, can I do the repair without opening another inspection port? And what should I use? I was thinking of using Marine Rx, but thought adding fiberglass might be better.

    Does anyone have thoughts/experience? I'd greatly appreciate it.


    I attached a photo of the damage, although it was hard to take a good picture of. Plus a shot of her in action, just 'cause.
     

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  2. Webfoot1

    Webfoot1 Active Member

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    Not sure where you inspection ports are. You can work through an 8 inch port behind the splash rail but it will not be easy to lay-up fiberglass around the tube. If I were doing it that way I'd stick to trying to use strips of fiberglass wrapped like bands. A smaller port next to the mast tube would be easier, or, if your boat is starting to acquire a Swiss-Cheese look you
    can pop the front deck from the hull. This allows best access to the tube and easy repair but you will need to remove and reattach the center front foam block. Sort of a trade off on best repair vs. what you feel your skill level is. In this case wrapping 2x2 layers of mat and
    cloth around the outside of the tube should do the trick. As a disclaimer, yes you can
    crack the deck trying to get it apart. As in all things, if it don't go don't force it.

     
    Last edited: Sep 8, 2016
  3. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    My mast is a loose fit in the step, so it may be possible to fix without cutting holes. (But my mast step "holds water"). ;)

    In your case, if there's enough room, I'd try a three- or four-inch strip of cloth tape and patch only where the split is—use slow-set epoxy with colloidal additives. Sand before starting, and after adding any additional strips. If you can begin the repair with two strips of cloth tape, overlap the two at the crack.

    If possible, add the mixture, then tilt the Sunfish so the mixture has a chance to penetrate the damaged area. Invent some way to press the cloth against the crack, and still be able to remove that agent—whatever it is. Pipe/Mast/wood dowel with multiple turns of masking tape—or some other "release agent"—Great Stuff foam, tailpipe scrap, tailpipe-expander, whatever.

    Epoxy is so strong, that old mast step would be imperiled anywhere-else the "fix" didn't go. :cool:
     
  4. paddywagon

    paddywagon New Member

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    Yeah, a fix where I don't have to cut holes or remove anything is preferable. There's definitely some play in my mast step, so I think I could patch it from the inside. L&V, when you say cloth tape, do you mean fiberglass cloth? I haven't heard of that, bit then again, I'm still new to a lot of this. Can you link to a product you like?
     
  5. JohnCT

    JohnCT Active Member

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    Lay up a couple of cloth strips with a little thickener mixed with the epoxy.
    Something like a 2" and 4", lay them out on a piece of Saran Wrap, wet out the cloth, take the whole mess and line it up over the crack. Get one of those sausage shaped kids party balloons and stick it in the hole and blow it up, you now have a perfect form fitting clamp, and when dry, peal the plastic off and you have a glass smooth finish
     
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  6. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Fiberglass "tape" can be found in most hardware stores, boating stores, or West Marine stores. If you don't have any epoxy, "flux" brushes, gloves, or hardener, buy a West Systems kit. For less than $40, there should be enough materials to fix the mast step as I've described above. Cloth is included, but not the "tape" that makes this repair a "slam-dunk".

    *Edit:

    John CT replied as I was writing. He's got the answer for a repair without tape, and where the kit would definitely fill the bill.
     
    Last edited: Sep 8, 2016
  7. Webfoot1

    Webfoot1 Active Member

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    If you try to fix from the inside of the tube be careful, If you get a bump in your repair that
    will not let you insert the mast, you are not going to be able to get at the repair to grind the
    area flat. How about this, coat the mast with mold release, lay up 2X2 mat and cloth over
    the mast to make a tube. When dry, remove the new tube and insert insert/epoxy into the mast hole.
    Reapply mold release to mast and insert in mast hole to assure mast is fits in
    new tube liner once installed.
     
  8. Light and Variable Winds

    Light and Variable Winds Well-Known Member

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    Although "over-strengthening" the mast step isn't a bad idea, JohnCT's method allows some desirable "slop". :cool:

    To allow the mast to rotate against the mast's black (plastic) cap, the mast step's original bottom should remain the same—or smoother. It seems extreme for a Sunfish :oops: but a Teflon "button" has been long available for catamarans for that very purpose.

    Fiberglass cloth "tape", if you go that route: :)
    [​IMG]
     
  9. paddywagon

    paddywagon New Member

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    Thanks everyone for your options and opinions. I'm hoping to tackle this tomorrow. I have everything to do the repair using fiberglass from a previous project patching a pretty serious crack in the hull. I'll let you know how it went!
     
  10. windwardde

    windwardde New Member

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    New to this forum, and had mast step issue with my sunfish. This forum and topic has been very helpful.
    Mine had cracked at upper 1" of the step, and lost some fiberglass and gelcoat. This lead to a leak in the upper portion of step.
    I tried to find balloons of the right diameter, but my local party store's balloons were too small in diameter.
    Found a length of 2" pvc pipe that was just larger in diam. than a sunfish mast.
    Ground out the upper area with wire brush on drill. Laid in a couple of 2" strips of wetted fiberglass mat around the diameter, using colloidal silica as thickening agent. Stuffed the area behind the strips with fiberglass mat and epoxy. Made sure the diam. stayed bigger than the pvc pipe. Let it harden. Scuffed it up and laid down another strip that also came up over the deck a half inch (notched cuts for relief). Placed the pvc pipe in the step, all the way in, after I had taped wax paper around it. Stuffed more thickened epoxy into the area between pvc and step, where gaps. This left a small raised area of fiberglass and epoxy above the deck height that I now need to sand down. Created a pvc grommet that I will 3m5200 and screw to the deck. The area is strong, smooth, looks good and I could pull a vacuum in the hull, so no leaks.
     
  11. Eddie_E

    Eddie_E Member

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    Another tip I found when I did this on my Sunfish was to use a 1" wide artist paint brush to wet the inside of the mast hole. I also used a desk lamp with a flexible neck to shine down into the hole. I used a can of brake cleaner followed by acetone and then a very light sanding with sandpaper wrapped around a 2" PVC tube. West Systems 205/206 is holding really well, even after sailing in 20+ knot winds several days. I also did the dagger board slot. Now I have the only 100% dry Sunfish hull in our club.
     
  12. Dickhogg

    Dickhogg New Member

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    Where I sail a lot of the Laser sailors put a plastic disc in the bottom of the mast step to protect it from wear and help the mast rotate. Apparently a pringles lid works well.
     
  13. Whitecap

    Whitecap Member

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    PaddyWagon,
    Here is a website that will help you find the date. Scroll down on the left to find the corresponding dates.
    Sunfish model year table

    Looks like a 1971.

    Hope this helps,
    Whitecap
     
  14. windwardde

    windwardde New Member

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    As a followup. Sanded it down, marked out the holes for the PVC grommet and glued and screwed it down with the 3M 5200. Rock solid and waterproof. With some help from another forum member, got the strips for the mast and a base plastic for mast and this is now better than new and looks professional.
     

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