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Cutting Hole In Dash?

Discussion in 'Early CJ5 and CJ6 Tech' started by Buildflycrash, May 9, 2019.

  1. May 9, 2019
    Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

    Gulf Breeze FL...
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    I need to cut a 2 1/16" hole for an additional Temp gauge.
    I really don't want to remove the dash as everything is done and new.
    I have a nice new big variable speed 1/2" Drill. Should I just go at it with a hole saw and go slow? Obviously my worry is having the bit wander and not getting a perfect hole without scratches!
    Whatd'aY'all think?

    [​IMG]
     
  2. May 9, 2019
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Beach66Bum likes this.
  3. May 9, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    They do sell adjustable circle cutters that can be used with more precision.
     
  4. May 9, 2019
    Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

    Gulf Breeze FL...
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    Like this? will cut thru dash? Home Depot is just down the road!
    At under $20 it is $100 less than that SWAG knockout punch!!
    [​IMG]
     
  5. May 9, 2019
    maurywhurt

    maurywhurt Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    tcfeet and Beach66Bum like this.
  6. May 9, 2019
    Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

    Gulf Breeze FL...
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  7. May 9, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    That's it. They work and don't wander. Just takes patience.
     
  8. May 9, 2019
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    Needs a steady hand... I prefer to save these for a drill press.

    The hole saw would be my choice if the rough edge can be concealed.
     
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  9. May 9, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    You have to be steady for sure, but the knife edge works better for cutting and not tearing paint. I've done holes with them successfully, the slower the speed the better.
     
    PeteL likes this.
  10. May 9, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    If using a bimetal hole saw, do yourself a favor and predrill the 1/4" center hole. Get a section of 1/4" round stock from the hardware store and use that in the hole saw as the centering rod. There's nothing worse than the holesaw grabbing, breaking the drill bit, and making a mess of the base metal as it walks 5" before you can stop it. The roundstock will bend a little if it needs to, but it won't break and make a disaster.
     
  11. May 9, 2019
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    If your going to drill the dash, then a bi-metal holesaw. Do you consider an under-dash gauge mount so you don't have to cut the dash?
    Oh, I see you've already got two gauges over on the left, nevermind!
    -Donny
     
  12. May 9, 2019
    Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

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    I did. but I thought it would look better in line with the other gauges. photo above.
     
  13. May 9, 2019
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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  14. May 9, 2019
    Lockman

    Lockman OK.....Now I Get It . 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Silver Hill,...
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    I need to cut a 2 1/16" hole for an additional Temp gauge.
    I really don't want to remove the dash as everything is done and new.
    I have a nice new big variable speed 1/2" Drill. Should I just go at it with a hole saw and go slow? Obviously my worry is having the bit wander and not getting a perfect hole without scratches!
    Whatd'aY'all think?

    Ive been a Locksmith/ Installer and Cj5 Aficionado for many years. I have Bored thousand's of various size trade related holes in steel doors , 90 percent of the time with bi metal hole saws . Always center punch then bore a 3/16 " pilot hole before using a Hole saw in metal. The pilot used in a hole saw mandrel is typically 1/4 " & will always follow the 3/16" hole. The pilot used in a hole saw mandrel is designed mainly for boring into soft materials. I'm fairly certain the thing that home depot sells is a circle cutter , mostly for crafts ; wood & plastics. Depot also sells Bi metal Hole saws and mandrels. Good investment when working on our CJ's. Please take the other very skilled fabricator's advice. ( ITLKSEZ, Keys5a, maurywhurt and the other fellas ).... BTW, I just did the same installation , over a GM tilt steering wheel in my ' 75 CJ5. I had to 'L' head in at a angle ! .....Still ,the center punch & the beginning
    3/16" pilot hole saved me, of course. Please see the pics. Good Luck & Take your Time .
    ------Lockman
    All Done 1.JPG All Done 3.JPG Starting Gauge Install.jpg
     
    Tom_Hartz likes this.
  15. May 9, 2019
    Tom_Hartz

    Tom_Hartz Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    North Carolina
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    I would do a test hole on a piece of scrap first.
     
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  16. May 9, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    +1 - the fly-cutter type needs a stationary axis. Hole saw or punch for cutting such a hole in situ.
     
    Tom_Hartz likes this.
  17. May 9, 2019
    Oldriginal86

    Oldriginal86 Member

    Pasadena, Md.
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    I’ve cut many holes for gauges in metal, fiberglass and wood. Always used a hole saw. Cheapest and easiest way to do it. Mask off the area, drill the pilot hole to 1/4” turn the pilot bit around in the mandrel and have at it. Slow and steady with a nice sharp tool. Good luck and don’t over think it, you’ve got this.
     
  18. May 10, 2019
    Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I live South of...
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    Like ITLKSEZ says, I would use a 2" hole saw, a little under size, because they wander. Then tape the dash in the area over, drill a 1/4" hole first, then I turn the drill in the hole saw up side down so you are using the shank for center, that way it does not have a tendency to wander as much. I have had hole saws jump over and make a mess instead of a nice round hole. It also helps if you tip your drill a little and let it cut the hole slow and a little at a time. Works for me. Good luck
     
  19. May 10, 2019
    65seejayfive

    65seejayfive Blazin’ new trails

    Pennsylvania
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    I am so lucky to have access to a Greenlee hydraulic knockout set at work that has dies from 3/8” holes up to 4” holes. A knockout punch set makes perfect holes. Buildflycrash if you were closer I’d gladly let you use it! But like said before I use a holesaw daily and the best way for a clean cut is always a pre-drilled hole for a guide. The pilot bit on the holesaw arbor will almost always wander a bit, even when new.
     
  20. May 10, 2019
    baldjosh

    baldjosh Member

    pacific north west
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    Just a couple days ago I cut the hole for my speedo (repop dash)...and used this type of cutter. dash was on the work bench with a chunk of wood behind it and using a hand drill... I would highly recommend NOT using this cutter in place...it was a serious pain in the A**...turned out nice but...wow...lotsa sweat and cursing
    If cutting in place I would think a 2x4 as a brace between dash and firewall would be a great help
     
    Buildflycrash likes this.
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