Gluing Starboard to transom

Discussion in 'Boats, Motors, Trailers and Towing Rigs Forum' started by Captain PartyMarty, Apr 27, 2020.

  1. Captain PartyMarty

    Captain PartyMarty Well-Known Member

    Hey Guy's

    I would like to know if any of you have had any success gluing starboard to your transom? The purpose would be to avoid drilling holes to mount sonar units? I saw this product but I don't see what they are doing different which warrants there product.

    Looks like marine Tex offers the same epoxy product

    looks like the process would be sand, alcohol clean, flame treat and glue.

    Anybody do this on there boat? if so is it holding?

  2. ExFlyGuy

    ExFlyGuy Well-Known Member

    On my last boat I glued a piece of starboard to the transom with 3m 5200. I used it to screw the transducer to so not as much load/force possibly as your going to have. I never did any prep to the area besides a quick wipe with acetone. It was rock solid 1.5 years later when I sold the boat.
    brutus and abl like this.
  3. pescador

    pescador Well-Known Member

    I tried it with 5200 last year and it got ripped off in the Frasier hitting a small branch. Lost 2 transducers. Don’t do it. Costly mistake and a lotta work to fix. Maybe another adhesive. But not 5200.
  4. Rain City

    Rain City Crew Member

    Properly used 5200 will rip your glass right off to the plywood. I've done it.
    brutus likes this.
  5. littlechucky

    littlechucky Well-Known Member

    I am considering doing the same.

    My understanding was starboard / 5200 would be rock solid if the starboard is treated properly as @Captain PartyMarty laid out.

    I haven’t heard of another simple solution and am open to suggestions.
  6. fishin solo

    fishin solo Well-Known Member

    5200 used properly like RC said the shit will rip everything off down to the wood. Done it too
  7. tubber

    tubber Well-Known Member

    Looks like the sternsaver product has some grooves in several holes to grab the epoxy. Couldn't this be copied with some ingenuity?
    Rain City likes this.
  8. Rain City

    Rain City Crew Member

    Is ingenuity a brand name of sandpaper?
    tubber likes this.
  9. Captain PartyMarty

    Captain PartyMarty Well-Known Member

    I actually think they cut rings inside of the those holes (Kind of like O-ring Grooves) as I bet there epoxy doesn't actually stick that well to the starboard but it does stick well to fiberglass or aluminium. The epoxy has a mechanical connection to the starboard through the groove once it hardens which makes it hold. To buy the Marine Tex epoxy is almost as expensive as buying the stern saver so I might just buy that and try it out
    Sentinel likes this.
  10. tubber

    tubber Well-Known Member

    Sharpened allen key in a drill with a changing number of warshers in the hole to control depth could work. You work on the keeping it centered part.
    Rain City likes this.
  11. brutus

    brutus Well-Known Member

    I have done it and like Rain city said, if done proprely the glass will come off with the plastic still glue to it lol, light sanding and clean with white gas let it dry and glue it on with 5200, ps dont expect to take it off, once its on it stay on
  12. island idiots

    island idiots Active Member

    Would acetone work instead of white gas?
  13. Rayvon

    Rayvon Well-Known Member

    I've done it many times to my boat and others.Cut starboard to desired shape,pencil in or mask around it,sand with 80 grit,wipe with acetone.I cut 1/8 deep table saw cuts in back of 3/4" starboard every inch or so and I use Sikaflex to bond,or 5200. You can use masking tape to hold in place after pressing it against transom,but most often it holds fine without.Never had one come loose .
    brutus and littlechucky like this.
  14. littlechucky

    littlechucky Well-Known Member

    A couple questions:

    - will bottom paint stick to it?

    - is 3/4” thick enough to mount a transducer or is 1” better?

  15. trophywife

    trophywife Crew Member

    manis bond- industrial grade... I put that shit on everything.
    brutus likes this.
  16. beemer

    beemer Well-Known Member

    Starboard was never meant to be glued . Use cutting board material instead. If you already have the starboard here are the instructions from the manufacturer.

    StarBoard can not be glued using standard adhesives. Products like 3M's 5200 work well as a water sealing caulk but will not adhere StarBoard to itself or other materials in a permanent bond.

    It is preferable to mechanically fasten StarBoard but when an adhesive is necessary you can use a product called #7540-AB or 3M's Scotch-Weld DP-8005. We do not represent these products, make any claims about their abilities or accept liability for them. We have however used them with success and had good response from others who have used them.

    How Should StarBoard® Surfaces be Prepared?

    The surfaces to be bonded should be lightly abraded with a medium grit sandpaper before cleaning the surfaces with acetone, Toluene, or alcohol.

    StarBoard should then be flame-treated on the entire surface to be bonded with a propane torch. Pass the flame over the surface at a distance of approximately 1" to 2" so that the blue (oxidizing) portion of the flame is touching the surface of the StarBoard at a rate of approximately 12" per 3 seconds.

    There should be no scorching or visible difference in the surface appearance when properly treated. Ideally, the surface prep should be performed within one hour of the bonding process. Make sure to flame treat in a safe well ventilated area.

    How Should Other Marine Surfaces be Prepared?

    When bonding plywood, insure that the surface is dry and clean. No other surface prep is necessary.

    When bonding aluminum, steel, and FRP, lightly abrade the surface with a medium grit sandpaper. Clean the surface with acetone, mineral spirits or alcohol. For the best results with aluminum, surface oxidation should be removed and an appropriate aluminum primer should be used to prevent further surface oxidation.

    How is the adhesive applied?

    #7540-AB is a complete adhesive system that includes a two part adhesive cartridge, a static mixer attachment for equal blending of the adhesive and a dispensing gun. Adhesive is dispensed by installing the static mixer on to the adhesive cartridge, cutting the tip of the mixer for desired bead size and pumping until the mixing chamber is full.


    Discard the initial amount of adhesive that is not fully mixed to a consistent ivory color. Apply adhesive equally to each surface to be bonded with an even coat of approximately 8-12 mils. The adhesive should then be spread over the surface with a putty knife or metal spatula. Join the two surfaces, securing with a spring clamp or similar "C" clamp for proper pressure (2-4 PSI) for a tight bond. Excessive pressure will squeeze adhesive out of the bonding area. Optimum adhesive thickness is 15-20 mils when cured.

    Working Time: Approximately ten minutes in average temp. of 65-100 degrees Fahrenheit.
    Clamp Time: Approximately six hours with a cure time of 24 hours.
    Coverage: Approximate coverage is one sq. ft. with a 20 mil thickness per 50 ML cartridge.
    Cured Bond Line: Application of adhesive at 8-12 mils per side, curing to a 15-20 mils thickness.

    Download (pdf format):
    Working with King Starboard

    To learn more on Starboard visit

    Sentinel and ericl like this.
  17. Rayvon

    Rayvon Well-Known Member

  18. terrin

    terrin Well-Known Member

    Use the Sternsaver it works great. They have 1" thick product and it holds a big TM260 no problem.
  19. SpringVelocity

    SpringVelocity Well-Known Member

    This is what I would do. Use router and put a simple pocket on other side. Clamp it somehow. Drill two holes opposite/ counter sink other side.

    One hole to fill, and when it come out the other hole its done. You will get hardly any air pockets and get a larger surface area making it stronger. Use what you want sikaflex, Dow corning 995 etc.

    Put a chamfer on edge on backside on simple put a bead around to seal it.

    Last edited: Apr 28, 2020
    Foxsea likes this.
  20. RiverBoy

    RiverBoy Well-Known Member

    Now i don’t want to throw a wrinkle in this discussion, but i’m going to anyway. i was told that the crack between the boat and the piece of starboard will have to be perfect or it will create bubbles or other disturbances that can throw off the transducer. i guess you could fill it using the same5200 you used to bond it to the boat?

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