Soft spot in the flooring of Fiber Glass Boats

Discussion in 'Boat Repair Help' started by AwShucks, Feb 18, 2006.

  1. AwShucks

    AwShucks New Member

    Guthrie, Oklaho
    Many times when reading advertisements for the sale of a fiberglass boat, you will see "floor has several soft spots" or "weak flooring". Is this a serious condition? Must you replace the floor or can you simply drill a hole in the floor (making sure you don't drill through the hull) and pump a can or several cans of foam into the floor cavity? How concerned should a person get?
  2. Mark J

    Mark J New Member

    Four Oaks, NC
    It is a pretty major fix if you arent fix it savvy.
    If you are handy with tools it is a time consuming project and several hundred dollars to fix.
    Dont bother if you arent going to fix the problem. A patch job isnt going to work in this case. Those cans of foam would have bought a yard or two of good fiberglass for the repair.

    Assuming this boat is a 16-18 feet in length I would rate this project from 1-5 as a

    5- technical ability. If it is a 2 piece hull you'll need to remove the outboard and disconnect the wiring harnesses in most cases, along with the steering and throttle. Almost any and eveything attached to the top piece of a 2 piece hull has to be removed. Be able to seperate the hull and get it back to together.

    3- for the repair itself. There is a learning curve using epoxy and glass but a
    beginner that can read and comprehend that curve is small.

    2- for the cost. The only way to fix anything is the right way.
    Epoxy , fiberglass, and the proper plywood arent cheap by most people's standards but put into perspective it's cheap enough to FIX the problem.

  3. fwmud

    fwmud New Member

    Wilson's Mills,nc
    What Mark should have told was "Just ask keith" . I had a "soft spot".
    It turned out to be a rotten poor patch over a already rotten, water sogged floor, patched/repaired incorrectly.
  4. Bubbakat

    Bubbakat New Member

    Most of the time by the time you floor gets soft the older boats were bad about this. The open cell foam they used was already saturated and the stringers were rotten.
    I have gotton a few good deals from boats that had soft floors.
    I always go in and redo the stringers and floor. I always install new foam and don't cut corners either because it will come back to haunt you.

    There are some good books out on restoring glass boats and they will help.

    I have an old 1974 Delta bass boat now I total restored and it looks good and rids sound.
  5. metalman

    metalman Well-Known Member

    Everything said above is true. If you buy a boat known to have a soft floor you should expect to spend a good deal of time and money to fix it. It took me about 3-4 months to replace the floor on the boat I bought. I knew it was soft going in but it was a really good price; the engine alone was worth more than I paid. I did it at weekends and in the evenings and you MUST have somewhere indoors to do the work.
    My original plan was to cut out the soft parts and put in patches but I found that the soft spot was just the tip of the iceberg and I ended up completely gutting the entire inside of the boat to a bare shell as the stringers were rotted.
    DO NOT be tempted to use polyester resin because of cost, epoxy is a must. DO NOT be tempted to skip on the amount of epoxy used because of cost, every piece of wood you use must be covered with epoxy. Do NOT be tempted to use cheap lumber, use marine grade ply wood for the floor and either the same ply wood or Douglas Fir for the stringers. DO NOT skimp on the amount of fiberglass you use, every stringer joint must be glassed and use at least 3 layers over the floor with the glass running a few inches up the sides of the hull so there is no way that topside water can penetrate.
    Any fasteners should be stainless and finish off with a couple of coats of white epoxy paint with either non-slip additive or self adhesive non-slip patches at key places on the floor. Done this way you can hose it out after fishing and it will look great. To give you an idea of price, just five gallons of epoxy and a gallon of hardner will cost you about $350 so this is not a cheap project but it is a way to have a solid boat without spending thousands. Obviously, if you do not plan on keeping the boat then this kind of expenditure is not a good idea but done properly the floor will easily outlast the rest of the boat. West Systems (not West Marine) has some excellent tutorials and literature on how to do this job and on epoxy techniques in general. Good luck...W
  6. AwShucks

    AwShucks New Member

    Guthrie, Oklaho
    Mark, OK, I get the picture for a two piece hull. What about a single piece hull? Do you like just take your skill saw (or other cutting implement) and cut out the floor, withour going through the exterior hull. Then remove the rotted stringers, replace the stringers and fiberglass over them? Then my next problem would be to find marine grade plywood in Oklahoma. So, can you use an exterior grade plywood and cover it with a maring spar varnish? Then apply fiberglass over that? I'm not a rocket scientist, but I do work some with tools, think I could do that. And I have done some fiberglass repairs on items other than boats. Imagine it is the same principle.
  7. bigflathunter

    bigflathunter New Member

    Lawrence, KS
    I too have a boat that had a "soft spot" in the floor. Turned out the entire floor was rotten, the stringers were rotten, the transom was rotten, etc. I ended up ripping out the entire floor, stringers, the inside skin of the transom, to where I had an empty hull and rebuilt the entire thing. It is not hard work, just very meticulous and time consuming. You have to be willing to read everything you can get your hands on and spend all the necessary cash to get good materials, and then take the time so everything comes out as near perfect as you can get it.

    Check out my photo section here at the BOC to see most of my rebuild process.

    I spent $800 on the 14' boat and I've got probably $500 worth of materials in it so far, including stringer wood, plywood, epoxy, glass, fillers, various nickel and dime crap like mixing cups, squeegies, gloves, etc., and I still need to order another gallon and a half of epoxy. That also includes stuff like like under sole plumbing, wiring, new lights, etc. Depending on the age of the boat you're looking at, it may not worth the money (mine is not). I'll never get the money back out of mine. I did it for the experience. That and if I have any gripes about the layout of my boat, it's my fault. For the money I've spent, I couldn't have found a boat set up exactly how I want it, anywhere, period.