Trim tabs for Aluminium boats

Discussion in 'Materials' started by Mat-C, Mar 9, 2011.

  1. Mat-C
    Joined: May 2007
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    Mat-C Senior Member

    Is it ok to use stainless steel trim tabs on an aluminium boat that will spend much of its time in the water?
    If not... any suggestions? I looked at the QL interceptors, but by all accounts they would better suit a higher speed boat - this one operates at quite low planing speeds
  2. Dean Smith

    Dean Smith Previous Member

    yes pretty much all aluminium boats use them
    do not forget that your anode is your protection against the electrolytic action
    You could achieve a total mech isolation with bushes and gaskets but really there will be no trouble
  3. IMP-ish
    Joined: Jan 2011
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    IMP-ish powerboater

    Maybe not the right shape, but the Bennett sport tabs have a black finish. I painted mine 5 years ago to match the same black/shine of my drives. But the black base coating from their factory has not come off at all in 10 years. The "ram" cylinders are plastic.
  4. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Aluminum tabs would be a much more logical choice.
    One could argue that the boat becomes a giant sacrificial electrode for the stainless tabs, but the difference in surface area will probably reduce the effects.
  5. Hägar

    Hägar Previous Member


    pretty much NO producer of the standard flavour uses them. So, how did you collect your information?

    As CDK said, AL is the more logical solution.

    Hä Hä Hägar
  6. tabman
    Joined: Aug 2008
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    tabman Junior Member

    The black powder coating on the Sport Tabs acts as insulation between the stainless Trim Tabs and the aluminum.

    Stainless Steel Trim Tabs are indeed used on many aluminum boats. We supply many aluminum boat builders with Trim Tabs to be installed at the factory as well as many aftermarket owner installations.

    Insulating the Trim Tabs from the boat with non-conductive materiel, taking care to insulated the fasteners and installing zinc anodes on the Trim Tabs will prevent electrolysis from damaging the boat or the Trim Tabs.

    Since the application is on a lower speed boat make sure to select Trim Tabs that are on the larger size of the manufacturer's guidelines.

    Tom McGow
    Bennett Marine
    Last edited: Mar 13, 2011

  7. Mat-C
    Joined: May 2007
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    Mat-C Senior Member

    Thanks everyone. Clearly, I'd choose to use aluminium or composite tabs if they were readily available (why aren't they???). By the sounds of it, I'm down to just isolating and coating the stainless ones to the best of my ability...
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