Laser Mast step repair

Discussion in 'Sailboats' started by Bigfork, Jul 26, 2016.

  1. Bigfork
    Joined: Dec 2009
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    Location: Montana, USA

    Bigfork Junior Member

    Hi folks.

    I've got an old 74 Laser that's really hammered and showing it's age. That said, it's still a great learner and she still boogies. It was the boat I learned on. She was owned by my neighbors while growing up. We would pack 5 kids on it, get dropped off at the launch on Flathead Lake, and then smash around on it all day with compulsory dumps, flips, and long paddles...

    I want my 1.5 year old to thrash around on this thing in a few years :p.

    The mast step has been failing for a while. 10 years ago I did a sloppy repair but the time is now to do it right. The pictures show the removal of the old repair and all funky glass on the edge of the sleeve.

    So I guess I'm looking for process/repair suggestions. My initial thought was to put a plastic wrapped cup in the socket and then glassing a mini "volcano" of filler and glass to basically raise the deck a 1/2 inch or so. Messy, not pretty, but strong. Now though, I think that seems a bit rash...(?)

    Should I do this:
    1. using West 505, tape off underside of deck-sleeve seam (access through the black hatch), make peanut butter filler and goober a fillet in the hole using the tape beneath as a dam.
    2. Use a small bit of cloth on the deck surface to cover the newly welded seam. You might be able to see in the picture, the sleeve has a couple of cracks that creep 2 inches down the tunnel. I was thinking of taking a dremel and mining out the crack (cleaning it and opening it a little). More goober in the mined out cracks and wrapping the bits of cloth down the hole a couple of inches to reinforce the sleeve, deck seam.

    Does this all sound logical? Should I remove the gel coat on the deck to the same measure of the glass fabric to keep things flush, save room for gel coat (likely some white rattle can)? Should I leave my patch filler "square" or do I feather things into the surface. Right now the opening is square-ed off as seen in the pics.

    I'm a little concerned about how to keep any glass or filler that wraps down the sleeve smooth. If it's a lumpy mess in the sleeve, the mast/sleeve relationship will be's got to stay smooth.

    PS: I can go in through the black port and see my finger in the it's open through.

    Thanks people! (and remember, I'm not after pretty--just strong and functional)

    Attached Files:

  2. tom28571
    Joined: Dec 2001
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    Location: Oriental, NC

    tom28571 Senior Member

    Laser used to offer a repair kit for the many mast steps that failed because of poor construction methods. I had to do one of those myself. Nasty job but necessary. Maybe they still offer it.
  3. bruceb
    Joined: Nov 2008
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    Location: atlanta,ga

    bruceb Senior Member

    base repair

    Definitely try to find a repair kit if at all possible as it includes a whole new tube mated to a piece of deck. Check with a laser dealer or maybe someone at APSLTD that sells laser parts. The mast steps from your vintage used to fail when the bottom of the tube became separated from the hull bottom and then the whole tube cracked out of the deck. They could be saved from cracking if an access port was installed forward of the mast and the tube base properly glassed to the hull bottom, and I usually added some glass around the deck/tube from the inside as well. I think you could do about the same thing with yours if you added one other access port and did all the repairs with epoxy from the inside. Of course you will add several pounds, but it should be fine for your use. If your access ports are correctly located, you can also seal the top of the dagger board trunk to the deck and probably stop the usual leak there.
  4. Bigfork
    Joined: Dec 2009
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    Location: Montana, USA

    Bigfork Junior Member


    I'm aware of the mast step replacement kit. I'd rather not go that route as the general shape of the boat is not worth the labor and money for the replacement kit. The foot of the sleeve is still solid, it's just the wear at the top as the pictures show.

    Can I just fill and glass for a super simple fix that will last a few more years of limited use?
  5. CT249
    Joined: May 2003
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    Location: Sydney Australia

    CT249 Senior Member

    I had a complete mast tube failure that I just fixed by fitting a wooden ring at deck level. Last I heard, the sea scouts were still using that boat years later, so IMHO a simple fill and glass may be fine.

    However, make very, very sure the rake doesn't change. My boat was an old but goodie I got from someone I was coaching, just to keep my hand in. In the first championship race after I rebuilt the mast step, I scored more points (against me) than I had counted in the whole of my previous two championship series. Having the mast too upright by a couple of degrees had an enormous effect on upwind speed.

    I'd put the bottom section in and measure the rake before the repair, then check it after the repair and either fill or grind to make sure the rake was back to the right measurement. I basically blew up a great old warhorse by stuffing up my repair; don't make the same mistake. I miss that boat.
  6. Skyak
    Joined: Jul 2012
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    Skyak Senior Member

    Your plan is generally pretty good. I have an old laser with the mast base repaired and lots of ware at the top too.


    -Read the west epoxy manual -the bible of fg repair.

    -you definitely need to taper the edges of the old to stick to the new and the old gelcoat should be removed where the epoxy is intended to stick. The West manual explains it all. If I recall they recommend a 7 or 8 to 1 taper -which makes a big hole and leaves the problem of forming the part of the boat you ground away. This is where experience and innovation are required. Beginners will try to save the old and make up for lost strength with mounding and grinding new fiberglass. I would suggest you add the inspection port, taper the old properly from the inside of the hull, make a form for the inside of the mast tube with sheet plastic or aluminum, and make the big ugly wrap of fiberglass on the inside of the hull. -Easy large overlap for strength, minimum finish work.

    If you keep the deck flat around the mast you might do what I have been considering (and wanting to ask the board) and bolt on a plastic collar cut out of a HDPE cutting board. The benefits would be a more precise mast position with lower friction that is easy to replace.
  7. tspeer
    Joined: Feb 2002
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    Location: Port Gamble, Washington, USA

    tspeer Senior Member

    Besides the deck/cup junction, another problem area on the Laser is the attachment of the mast cup to the bottom of the boat. I had that junction fail while sailing, and the mast ripped up the deck as it came down and levered the cup. It's a tough joint to assess, because there's no access to it.

    Perhaps it would be worthwhile to drill a hole through the bottom of the cup and hull and insert a bolt, solid rod, or fiberglass bundle that would ensure the shear stress at the bottom of the cup is not entirely reacted by the bond?
  8. tom28571
    Joined: Dec 2001
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    Location: Oriental, NC

    tom28571 Senior Member


    Early Lasers had the mast tube set in a plywood circle bonded to the bottom with resin. While I'm sure they had circle cutters in the shop, some slug used a saber saw or bandsaw to cut the inner hole by cutting through from the outside. Of course, that is where it failed. If it had been built properly, it would likely have never failed. I loved sailing them but Lasers are pretty poorly built boats with a chopper gun and could be punctured fairly easily.
  9. Dave Gentry
    Joined: May 2010
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    Location: Charlottesville, Virginia

    Dave Gentry Junior Member

    IIRC, the tube is somewhat oval at the deck, allowing the mast a bit of both forward and aft rake, depending on the point of sail. It's been a while since I was racing Lasers, though, so you might want to confirm before adding rings or whatnot.

    For what it's worth, I would likely glass the deck-to-step joint heavily from the inside, fill the exterior holes with thickened epoxy, then sand down any roughness and call it good.

    As a point of interest, I've actually been inside a Laser hull, entering through a mast step repair kit hole in the deck, to replace some floatation up front. Exiting was made possible by folks pulling on my feet.
    I was younger then, and a little skinnier.
  10. BobBill
    Joined: Oct 2009
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    Location: Minnesotan wakes up daily, in SE MN, a good start,

    BobBill Senior Member

    Aolthough I am sure you have "fixed," (been lurking here) but I can offer one tardy but decent piece of advice, since the effort appears set...

    "Carbon," applied with care as filler and finish edges and would run a bit of tow around step opening. Should do the trick, unless other issues attend the step.
  11. Bigfork
    Joined: Dec 2009
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    Location: Montana, USA

    Bigfork Junior Member

    Hi folks.

    Haven't posted in a bit but here's my plan. Because this is just a crash-about boat I've decided against big operation-like the mast step repair kit. Since the tube/deck relationship is only about 30% compromised, I got a new plan. Imagine the area of damage is like a "crescent moon" on only one side of the relationship. I've already got it patched and fared.
    I sourced some 1" HDPE plastic. I'm going to cut a "doughnut" shape that perfectly fits the dimension of the sleeve. The hole is elongated as the exit through the deck is not a truly round hole (not sure if this is factory or just years of wear). I've got access to a CNC that's going to cut the elongated profile of the hole. This will then be stainless bolted thru the deck to a piece of doughnut greentreat ply beneath the deck, ringing the sleeve from underneath.
    It's essentially a collar that will help to displace the stress and load at the deck/sleeve joint. The mast will press upon the HDPE with equal pressure just like it does as is leaves the sleeve. Shouldn't change mast rake. The HDPE will sit proud of the deck by it's thickness (1") and basically make the mast sleeve an inch taller.

    So HDPE doughnut, some 3m5200, 5 stainless bolts/nuts, a chunk of marine ply inside, and done...KISS solution that should last years.
  12. Skyak
    Joined: Jul 2012
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    Skyak Senior Member

    That's my suggestion from post #6 so IT"S BRILLIANT! I am not so thrilled about the plywood backer I fear will rot inside the moist hull. Encapsulate it well and glue it against the inside hull.

  13. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    You could grind all around the deck where the mast hole is, wrap the mast in plastic or some other resin barrier, insert it and laminate around it. Probably seal the top of the mast/hole with some clay first to keep the resin from running down inside between the mast and the tube. Start with a bigger circle on the deck and then smaller and smaller until it's built up enough. Pull the mast and then sand the repair smooth, ending up with a smoothly tapered reinforcing ring similar to an ant hill.

    You should wrap the mast with enough stuff above the mast hole to give the same clearance as the original setup has, or give enough clearance to get the mast out and then finish size it by sanding with a tube wrapped in sandpaper.
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