Announcement

Collapse
No announcement yet.

floor rebuild

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • floor rebuild

    Hi all

    Great website. I have been looking at project pics for a while but have really been waitng for forum and classifieds. Anyway I picked up an old 71 Mako 22 really cheap but it has rotted subfloor that needs to be redone. I havent started yey still gathering info. My first question is can inner liner be removed from hull to expose wood? If not has any one reused skin from floor on such a project by cutting somewhere up on gunnel.

    Thanks again for great website

    Mike
    Mike[br]Milford Ct.[br]

  • #2
    The inner liner is nearly impossible to remove from what I hear. Mako put so much foam in there that its practically glued together by the foam. Not to mention, they probably have some bedding compound in there as well.

    Is the entire floor rotten from the bow to the stern? Or are there just a few soft spots and the rest feels solid? Let me know so I can give you my best input. Replacing a floor isn't that tough, it jst seems that way because it is such a large area and seems like alot.


    Slidell, LA 1993 Mako 261B - Temperance

    Comment


    • #3
      Most of the floor seems to be shot. From the casting platform in the bow to the fish box in stern seems to be very soft. I realize that this not that much floor area once you eliminate fuel tank box but I like the idea of keeping the molded in non skid if possible. If this is entirely impracticle what sort of skin do you reccommend?

      Thanks

      Mike
      Mike[br]Milford Ct.[br]

      Comment


      • #4
        Mako22,

        Most of the floors in the older mako's that feel spongy are suffering from delamination of the core (balsa I think) from the skin. This can be repaired by drilling a network of holes through the top skin and core, but not the bottom skin, and injecting resin. Use a small grid pattern, about 3-4 inches and inject the resin with a syringe. Most marine supply stores sell the west system syringes. after you inject the resin into the holes, use a flat spreader to level any excess poking up out of the holes before the resin sets up. The floor can then be repainted to match. Check out the WEST system book that West Marine and Boat US carry. It is only like $3.00 and gives a good overview of this process. Just a suggestion to aviod cutting out the floor and A TON of extra work.
        Greenwich, NJ[br]1976 22B

        Comment


        • #5
          I'm thinking that this floor is shot though. I'm betting you'll have to recore it from the top, which isn't that bad. You may even be able to salvage the fiberglass skin on the underside.

          What I'm eluding to is that you could scribe a line around the perimeter of the boat about 3-4" inward from the inner liner walls. The set a skil saw at a cutting depth of about 1/8" - 3/16" depending on how thick the top skin is. Cut that top skin off and peel it away revealing all the old nasty core material.

          Scrape and grind all that crap out leaving the bottom skin in-tact. With a grinder, bevel back fiberglass on the topside of the 3-4" section you left around the perimeter of the boat.

          Now you'll have to make templates so you can cut your new core material. I'd use NIDA core or Klegecell since both wil conform to any camber that the floor may have. Cut out the core pieces. Then sand that bottom skin to rough it up.

          You'll want to do this one section at a time. Now lay a piece of 1.5oz mat on it and paint a coat of resin on your new core section. Then place your new core over the freshly wetted out fiberglass. Stack all kinds of stuff equally across the surface of the core section while the resin sets. Once the resin sets pretty good move on to the next section and wet out the 1.5oz mat and glue in another piece of core material.

          Once the core pieces are all glued in you'll fiberglass the entire top side of the new floor with 2 layers of 1808 or something tough like that and a top layer of 6oz cloth for smoothness. You'll lap the glass onto that 3-4" wide section you beveled back to tie it all back together.

          Now I'd break out a good short nap roller and roll gelcoat onto the entire floor. After rolling the first coat you can sprinkle some non-skid onto it while still tacky and then roll another coat of gelcoat. You'll hve a real nice non-skid surface.

          I'd use vinylester resin for the whole thing, that way you can put the gelcoat on while the fiberglass is still green and you'll have a chemical cure.

          Its a little work, but you'll be guaranteed that it'll last. And it will be lighter too. But if you can't salvage the bottom skin you have to go to Plan B....


          Slidell, LA 1993 Mako 261B - Temperance

          Comment


          • #6
            Mako 22-

            If the entire floor seems shot, injecting epoxy will not do a thing. That sort of repair is only good if you have one small area that is bad.

            If your stringers are good, you basicallly need to remove the top layer(s) of glass and the rotten core (leave the bottom layers of glass alone) and replace with new core and reglass on top. If you start at the bow and work backwards and do about 3 foot long sections at a time, you'll can sit/stand on the old sections that you havent replaced yet. Plus, you'll have an existing edge to match up to so that your replacement work matches the original.

            If the stringers are shot, you;ll need to cut out the entire floor to get at the stringers and then after the're are fixed you can then replace the entire floor.

            Hope this helps.

            Ed

            Ed Mancini

            1991 Mako 231

            Tournament Edition

            Comment


            • #7
              Ed is talking about the same thing as I mentioned, but he raises a good point in doing the demolition and rebuilding in sections. I'd have to look at the boat to know how the fuel tank is situated and if that section of the floor/liner would be involved in any way.

              You could indeed redo it in sections and it would work out great.


              Slidell, LA 1993 Mako 261B - Temperance

              Comment


              • #8
                I would have to guess from the wat floor feels that the wood is rotted more than just delaminated. What advantages do the kledgecell and nida core have over plywood, is it just a weight thing or is there more. I understand these materials are very expensive. I will not be starting project for a while as it is cold in Ct. now but am very interested in maintaining this dialogue so that I have a pretty good idea of what I want to do before I start cutting.

                Mike
                Mike[br]Milford Ct.[br]

                Comment


                • #9
                  Mike this will give you a pretty good idea of what to expect.

                  The same would apply to the floor.

                  http://www.classicmako.com/projects/xshark/bw5.htm

                  Comment


                  • #10
                    The klegecell and NIDA have he ability to conform to a curve without being stressed. They only become rigid when there is fiberglass on each side. They are lighter and won't rot. And the price difference isn't that substantial. Your probably looking at $40-50 per sheet of NIDA and marine plywood is $80+ per sheet. So the NIDA is cheaper than the marine plywood. Regular plywood will run $20+ per sheet.

                    You'll need about 5 sheets of whatever you use. Honestly, the price difference is null if you ask me. Whats $150 more in the grand scheme of things for a far superior end result? Hell you'll spend $300 on just resin and nearly that much on fiberglass too. Your looking at $800 in materials... Sure you could save $150, but the NIDA core sure would be easier to work with as well. Did I mention that NIDA is 5X lighter than plywood?


                    Slidell, LA 1993 Mako 261B - Temperance

                    Comment


                    • #11
                      Warthog that is some untertaking you have going there, beautiful. What does the bagging do for you? Is it to insure better wetting out of cloth and to pull excess resin out? How is this process done? Do you put plastic sheet over repair area and evacuate it to apply pressure to repair.

                      Nice work

                      Thanks

                      Mike
                      Mike[br]Milford Ct.[br]

                      Comment


                      • #12
                        Ringleader ok I,m sold on the kledgecell thanks for the great input
                        Mike[br]Milford Ct.[br]

                        Comment


                        • #13
                          Eddie and Ringleader you both mention possibility of leving inner skin intact. I was wondering would I be better off having a lok at the foam? I have heard that the foam used in those days was open celled and am assumeing it is wet and heavy
                          Mike[br]Milford Ct.[br]

                          Comment


                          • #14
                            Correct, vacuum bagging not only gives a void free laminate, but like you mentioned, it wicks the excess resin out of the laminates giving you a nearly perfect resin to glass ratio. That aids in the highest possible strength at the least amount of weight.

                            Foam, I'd start by trying to leave the lower skin and when you have all the old core cleaned out, maybe cut a few holes in that skin with a big hole saw and cut down into the foam to see if its wet or dry. If dry proceed with finishing the floor section you are working on and move to the next and repeat the process. If wet... well make a decision... We'll be here to guide you through it all.


                            Slidell, LA 1993 Mako 261B - Temperance

                            Comment


                            • #15
                              Warthog and the Ed's are correct with thier statement above. My comments refer only to localized delamination. If your core is compromised throughout all or most of the floor, injecting resin will not be sufficient. The core will need to be replaced. It all depends on the extent of the rot once you get a good look at it.
                              Greenwich, NJ[br]1976 22B

                              Comment

                              Working...
                              X