Floor repair on Larson 186 SEi

Discussion in 'Powerboats' started by JR17, Mar 27, 2006.

  1. JR17
    Joined: Mar 2006
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Atlanta, GA

    JR17 jr17

    I need help. I bought a 1999 Larson 186SEi 2 or 3 years ago and keep it covered - and in covered storage.

    Sad to say but my 7 year old boat has a rotten floor. What started as a simple carpet replacement has now become a floor replacement.

    My questions are..

    1) What flooring should I use (in place now seems to be 1/2")? Seems thin for captains chair but I figure I can build it up as the chair base with fiberglass. I've read people use MDO (medium density overlay?), marine grade plywood, pressure treated plywood. I will probably use 1/2" marine grade assuming someone can tell me where to get it. Is 1/2" normal?

    2) Is is normal to just cut 3 to 4" from the side all the way around (at least in areas needing replacement)? Can I then just use filler (Bondo) to fill in the seams?

    3) How do I seal the wood? Do you then just laminate floor with resin (epoxy or polyester?). I read last night 3 coats epoxy resin with 1 layer of glass mat.

    4) Do I have to laminate both sides of the wood?

    5) I had carpeting but wonder if that was 1/2 my problem. Carpet does nothing but hold water. I heard about a product called Nautolex; it's a marine grade vinyl floor covering with non skid properties. Any one know if it is good stuff? Cost is the same as carpet but allows you to hose and scrub easier.

    6) My plywood cutting blade had a hard time with the fiberglass. Any recommendations?

    Thanks for any advice.

  2. KCook
    Joined: Jan 2003
    Posts: 171
    Likes: 2, Points: 0, Legacy Rep: 13
    Location: Arizona

    KCook Senior Member

    There are a number of boaters with projects such as this on the forums over on www.iboats.com

    Kelly Cook
  3. Martell_Florida
    Joined: Oct 2005
    Posts: 14
    Likes: 1, Points: 0, Legacy Rep: 14
    Location: Florida

    Martell_Florida Junior Member

    I just did virtualy the same project. It was my first time, and I had no idea what I was doing, but I did a lot of research and it turned out very good. First off, call Fiberglass Coatings Inc. (www.fcgi.com) in St Petersburg Florida for material and advice. Great group of guys who know their stuff. I am new to this, so keep in mind this is a matter of opinion.
    1. Make sure to use Marine grade plywood (or at least hardwood plywood). Resin will not stick to pressure treated or pine.
    2. When you cut out the old floor, cut on a 45 degree angle so your new flood (also cut on a 45) will have something to joint to. Sand everything, wipe clean, use tack cloth.
    3. (Encapsulation) Wet out both sides, and all edges with a thinned out coat of resin. I used polyester resin with 10% styrine. (as advised by fcgi). Make sure to wet out the exposed old floor as well.
    3. Use a structural fiberglass, stiched bi-axle works well. Cut to fit leaving at least 3" of overlap. Wet out fiberglass, then put to floor and roll out with a metal roller. roll, roll roll. Make sure you get out ALL air bubbles, or you will get to know your sander all too well.
    4. After it cures, put a second coat of resin down to "level".
    5. Sand and paint (or Gelcoat).
    I have been advised that the carpet can trap moisture and lead to the problem that you are having, so I sanded and painted my floor and it looks like a factory finish. Make sure when you are installing your captains chairs, you predrill and put resin in all of the holes to avoid water. I'm sure I missed a few steps, so ask around a bit...
    Good Luck!
    1 person likes this.

  4. marshmat
    Joined: Apr 2005
    Posts: 4,127
    Likes: 146, Points: 0, Legacy Rep: 2043
    Location: Ontario

    marshmat Senior Member

    If you intend to keep the boat a while, you might also consider a synthetic (polymer) board for the sole. While many marine plys are very good and, with fibreglass, quite watertight, polyboard materials are virtually invincible- rot proof and very tough.
    If you decide you still want a carpet, have it made as a snap-in instead of a glue-in. The snap-in variety can be taken out for cleaning and to dry, and the whole unit will last many times longer. I'm not familiar with Nautolex, but it seems like if you go that route it should be snap-in too, as vinyl can also trap water under it if the adhesive lifts a bit.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.