No announcement yet.

Mako 236 Inboard

  • Filter
  • Time
  • Show
Clear All
new posts

  • Mako 236 Inboard

    Hey Everybody,

    1980 Mako 236 Inboard
    RWC Mercruiser 350

    So I bought the boat last winter and immediately went to rewiring the whole boat and adding some electronics. After working through some issues with water in the fuel, we used the boat a lot this summer and put a lot of hours on the boat. Well, while I was working through the boat this year I noticed a couple of things that needed attention. First, engine access is horrible. I love inboard boats. I happily trade off the slower speed for the simplicity, looks, and manners that come with an inboard boats. That being said, the access to the engine on this boat makes basic maintenance far more difficult than it should be. Secondly, the engine is mounted to the stringers with steel brackets which the engine mounts bolt to. Well, 40 years in damp bilge took its toll on the brackets. So this winter I decided to address all the major issues with the boat, and maybe do some cosmetic upgrades if time and money allow.

    The following is a list of need to do projects:

    - Replace engine mounting brackets/engine mounts
    - repair soft spots in deck around console.
    - modify console to hinge up from deck to ease engine access.
    - Remove the foam from the rear bilge area.
    - Replace transmission cooler
    - Paint and clean up engine

    The following is a list of items I'd like to do but don't necessarily need to be done:

    - Replace fuel tanks
    - paint topsides and hull
    - Add leaning post
    - add fiberglass T-top

    The basis of this project is mechanical reliability and hopefully, we can squeeze some cosmetic upgrades in as well. I don't want to bite off too much at one time because it makes the project seem much more daunting. The goal is to be back in the water mid to late May. The project started mid-December and is progressing. The console is off, fuel tanks and engine are out, decks are up, and glass and resin will be delivered tomorrow. Some pics below.

  • #2
    I got the console derigged and the console out of the boat. Soon after that, we used the lift at the yacht club to lift the motor out of the boat. The motor mounts came apart as we lifted the engine out of the boat. Scary thought.


    • #3
      Once the console was out of the boat, we went to removing foam from the hull and working to get the gas tanks removed. I used a shovel to remove the foam from under the deck and it was thoroughly waterlogged. To remove the tanks, I used a jack to lift on the tanks from above and cut the foam around the tanks using a long wood saw. It was a bear, but they eventually came out. The tanks have obvious corrosion on them.


      • #4
        Once the tanks were out and the foam was removed, it was time to go about recoring the decks. I will not be replacing the entire deck but rather removing the outer skin, scraping out the rotten inner core, and then laminating the new core in its place. I will be going with nida-core to replace the rotten plywood.

        I have read a bunch of restoration threads and for-sale ads for makos of this vinatge that state "decks are solid". Well, the decks in this boat weren't "SOLID" but they felt pretty good under-foot. Just a heads up.

        I ended up taking core samples of the deck using a hole saw. The plywood core was soaked and completely rotten. I ended up cutting up most of the cockpit sole. Most of the core was so rotten you could just peel it straight out, obviously as evidence of delamination. The console was mounted to the deck with screws into the plywood core which ultimately led to the demise of the deck. A poor original design.

        read a lot about what to use to cut up the deck. A lot of people recommended a roto zip. I don't own a roto-zip, and cant use a jigsaw because I needed to control the depth of the cut, as not to cut through the lower deck skin, so I read somewhere that I should use a fine-tooth circular saw blade. Unfortunately, the fiberglass quickly overheated the fine-tooth blade, so I changed to a regular framing blade, which cut through the fiberglass and core with ease. Here are some pics of the process.


        • #5
          I'm curious...
          Since you had so much of the boat disassembled, why didn't you pull off the top cap instead of cutting up the floor?
          1992 211 w/175 OptiMax
          Glen Campbell, Pa.


          • #6
            I considered pulling the entire cap, but inspecting the deck from the underside, there are a lot of longitudinal runners that stiffen the deck from the underside that are all tied in together. Pulling the cap and replacing the core from the bottom would have required the removal and replacement of these members which I thought was an unnecessary step. Secondly, I'm working outside in a portable garage, so with the cap and hull separated, one would have to sit outside.


            • #7
              That makes sense...thanks!
              1992 211 w/175 OptiMax
              Glen Campbell, Pa.


              • #8
                Nice work Hellbent, i also have a 236, mines a year older than yours and a diesel. will be watching your journey closely - as i'd imagine i'll be doing the same as well. please keep the pictures pouring in.


                • #9
                  So to recore the deck I am going with nidacore. One of the biggest challenges of this rebuild so far is just sourcing all of the materials, at a reasonable cost. I discovered a company call Composites One. They have distribution centers around the county where you can pick up almost anything, saving you a ton of money on freight shipping. If you're in Jersey/the Northeast, ask for Adrian or Heather in Millville, awesome people to work with, and the prices were extremely competitive.

                  Today I drove down to Millville and they had my order waiting for me. To start:

                  - (3) sheets 3" Polyumac Aircomb (nidacore clone)
                  - (2) 5 gallon pails of vinylester resin
                  - (1) roll of 1708 (90 yards)

                  This should get me started. Hoping to lay up the nidacore panels on Saturday and get most of them bedded on Sunday. We shall see.


                  • #10
                    So this past week/weekend, we got all of the rotten core removed. We then made templates for all of the new core and then started glassing the 1708 to stiffen the decks up before bedding in the new core. We're moving along well. Again, the prior owner of this boat used so much injecta-deck that made the core removal process 10x more difficult then it should have been.
                    Attached Files


                    • #11
                      You are making good progress. I love these inboards, although I've never owner one, I've always wanted one. Project is coming along nicely. The only thing I would do is use heat shrink electrical connectors on all connectors. You can get them pretty reasonable from ebay.
                      1978 Mako 25 - Blind Hog[br]1985 Mako 20c - sold[br]Mary Esther, FL[br][br]


                      • #12
                        Thanks, Sailor. Yeah in hindsight, I knew better. I should have used heat-shrink terminals the first time around.


                        • #13
                          Started laying up the main deck panels tonight. They will get a layer of 1708 on either side and then will be bonded and beaded to the deck. Once they're bedded, I'll add 1708 to build back up the the existing thickness.
                          Attached Files


                          • #14
                            Last night I finished layed up the rest of the nidacore deck panels with one layer of 1708 on both sides of the core. Next will be bonding the core panels to the hatches and bedding the core to the deck.

                            Also, this weekend I picked up the newer style console from another 236 which features the metal windshield and grab handle. We've been trying to find one of these to replace the dated plexiglass windshield and flimsy grab handle on our boat. Anybody got any ideas where to source parts? Well need new seals as the windshield will be taken apart, media blasted, painted and reassembled.

                            I also picked up a compressor for $80. I'm starting to look at a rig to spray the hull and topsides and in order to meet the CFM requirements of most guns, you need a 3-5HP 220V compressor. This compressor is 120V and has a CFM rating of 8.2 @ 40 p.s.i. We won't be able to spray continuously, but well give it a try with the primer and see if we can make it work. If not, we'll just have to buy a big compressor. No big deal, either way, I just figured it was worth a shot.
                            Attached Files


                            • #15
                              Well, the nidacore panels now have one layer of 1708 on either side and they are incredibly strong and light.

                              On a separate note, what is everyone seeing for the costs of new engine mounts and fuel tanks?