Drilling Holes through gelcoat?

Discussion in 'Boat Yard Basics' started by MariettaMike, Sep 27, 2012.

  1. MariettaMike

    MariettaMike Wish'n I was Fish'n!

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    I need to expand a 3/4" hole up to 1" in order to get the cable for my new depthfinder through the console.

    I have a paddle bit and a hole saw in 1". I am currently planning to drill a 1" hole through a sheet of aluminum and then screw it down over the existing hole to act as an outside pilot.

    The question is which bit is better for drilling through the gelcoat without chipping? Does putting masking tape over the spot help minimize the chipping?

    Any help would be appreciatted.
     
  2. cutrunner

    cutrunner Cert. Yamaha technician

    One inch hole saw and blue masking tape.
     

  3. ASB73

    ASB73 Well-Known Member

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    I have used bits like this for my drill and worked it around the hole to make it bigger
    http://www.toolking.com/dremel-407-1-2-inch-drum-sander-bit?CAWELAID=482610143&cagpspn=pla&gclid=CK2Zjv_m1rICFQcGnQodNX8AmA
     
  4. jms

    jms don't let common sense get in your way

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    stepped bit - or "unibit"

    trying to use the hole saw is asking for trouble...

    fyi:
    blue masking tape is useless to prevent chipping...
    way to drill through gel without chipping is to run the drill in reverse,till you're through the gel,then switch the drill direction - doing this,the gel will never chip...
     
  5. DuckNut

    DuckNut Brandon, FL

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    Once again I agree with kreepa
     
  6. cutrunner

    cutrunner Cert. Yamaha technician

    [/quote]




    fyi:
    blue masking tape is useless to prevent chipping...
    way to drill through gel without chipping is to run the drill in reverse,till you're through the gel,then switch the drill direction - doing this,the gel will never chip...[/quote]
    I didnt know that. Thanks for the tip!

    Yea later i read back and realized what i had wrote about the whole saw.
    It would work, but it would be a real pita and you would have to be very careful.
    Is the surface your drilling thin enough for a step bit to work?
     
  7. MariettaMike

    MariettaMike Wish'n I was Fish'n!

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    Got r' dun!

    Found my 1-1/8" Unibit in the drill case right where I left it. Drilled the 3/4" hole out until the 1" hole saw would get in there and finished it off with that. No tape. Unibits are worth the price. The next hole I drill with it will be 1-1/8" for the Marinco trolling motor receptacle right through the front deck.

    Getting the holes for the mounting bracket screws the right size was actually the hardest part.

    Thanks for the advice.
     
  8. jms

    jms don't let common sense get in your way

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    i do this stuff every day...