Welcome Guest - Sign Up today
Welcome Guest - Sign Up today


No announcement yet.

Epoxy on MC Bravo 1 Transom assembly

  • Filter
  • Time
  • Show
Clear All
new posts

  • Epoxy on MC Bravo 1 Transom assembly

    I learned years ago the hard way that polyester resins will not stick well to metal auto floor boards. It will for a while but will eventually lift. I have some Bravo drive transom assemblies that have some corrosion near the bottom bolts on the inside surface. I may have lost 1/16" of aluminum metal after grinding off old corrosion. Applying a straight edge, I can see light through the crack. I'd like to build this area back up, since I will be torqueing to a flat and new transom. The quickest and cheapest is to thicken epoxy resins with glass and apply like Bondo to fill voids and raise surface, then surface or sand area to be flush with the rest. The most work would be to TIG up layers and then surface (lot more work). But, I don't know if epoxy resins will permanently stick to aluminum on a transom assembly, especially and eventually exposed to salt water. Any experience on this would be appreciated.

  • #2
    Go the TIG... The epoxy will eventually lift, and expose the bare aluminium to sea water. It's a fairly short road to a water leak from there.

    The world takes on a whole new perspective when viewed from 100’ below.
    1972 Bertram ‘Bahia Mar’ 20
    2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
    (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


    • #3
      JB weld works well
      1999 Powerquest 260 legend
      502 mpi


      • #4
        FWIW, bondo is a polyester resin that sticks to metal very well. With that said, the best method is to add more metal to the corroded area to build it up, and then smooth it out.
        1990 Wellcraft Eclipse 196
        Mercruiser Vortec 4.3 0M322285
        Alpha gen 1


        • #5
          If I were going to try a repair like that I would use one of the metal filled super epoxies, like Devcon Titanium putty. Kind of expensive $100/ pound but should be a solid fix.
          87, 4WINNS H 190
          470/Alpha I


          • #6
            weld 'er up
            grind to shape
            paint to match
            Cheesehead boating the Gulf Coast of FLA 27.51° N, 82.53° W

            1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - https://forums.iboats.com/forum/owner...988-rogue-2420

            Past Boats
            1970 Wooster Hellion - Merc 9.8
            2002 SeaRay 190BR - 5.0 - A1G2 - "Cheeseheads in Paradise"
            1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

            What’s behind you doesn’t matter.Enzo Ferrari


            • #7
              Watch this video about epoxies on metal:



              • #8
                All this glue stuff is great for your farm tractor. When it breaks, you walk back to the house. Not so good in a boat offshore.
                Mariah Shabah Z202 5.7L Mercruiser B3
                Jensen Marine 1972 Cal 21 cabin sloop
                Retired EE of 45 years


                • #9
                  Sign up today
                  thanks to all. I will try TIG first!