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Drilling a tank

Discussion in 'General Discussion' started by Cipher43, Dec 20, 2011.

  1. Cipher43

    Cipher43

    65
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    So with this 75 gallon im getting from AJ I have been thinking about drilling it for my parents.  Has anyone had any problems with drilling a tank?  With breaking it or cracking it or even just some tips?  Also i know alot of people go with the glass holes kits but is that best or could i just as easy use a bulkhead and an elbow with a strainer on it.  Also for a 75 gallon what size hole/bulkhead am i gonna need for it.  Her current 55 uses a hang on back style overflow but i would like to get away from that for them cause she has had some problems with it in the past.  My biggest worry with drilling is i dont want to break the tank after just buying it./DesktopModules/ActiveForums/themes/_default/emoticons/crying.gif
     
  2. iadubber

    iadubber Well-Known ReefKeeper

    376
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    I've never drilled a tank, but if you youtube you will find alot of videos. I am doing my 72 next week.

    I found a tip to get plumbers putty and make a circle of it around the hole you are going to drill and put water in and make a pond. This is after you use the template to start your hole also spraying water as you go. Set drill on slowest speed and if using a cordless set the clutch at it's weakest setting.
     
  3. a12ptbk

    a12ptbk

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    Its easier than you think as long as the glass isn't tempered and go slow anybody can do it. I drilled all my 40 breeders. I put tape on the underneath and a towel below where i am drilling just in case the tape didn't catch the piece that comes out and to soak up the muddy water
     
  4. blackx-runner Administrator Website Team Leadership Team

    Cedar Rapids, IA
    Ratings:
    +738 / 5 / -0
    Definitely check to make sure its not tempered before you attempt to drill. I'm sure someone in the club would be more than willing to lend you a hand drilling the tank. Its not really hard, but the first time is pretty nerve racking.
     
  5. ThyRaven

    ThyRaven Well-Known ReefKeeper

    919
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    +1 / 0 / -0
    +1 on nerve racking and AJ was even the one drilling my tank for me. lol. but yea all the youtube videos and advise mentioned above will get the job done. Or if you're close to North Liberty - Sea of Marvels will do it for cheap - $20ish I think.
     
  6. mcclandy

    mcclandy

    254
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    Agree, i drilled three holes in my 150tall. Did all the homework i could on the tank, manufacturer, and glass type before i drilled it; just to make sure it was not tempered. The first hole took me a long time, the second was a lot faster, and easier. I just remember taking it really easy just before i cut completely through. I just used a spray bottle with water ( and towels) to keep the bit and the glass cool. I think i bought my bit through bulk reef supplies.
     
  7. Cipher43

    Cipher43

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    I believe the 75 is safe to drill. Have to ask AJ to double check but im guessing it will be. I was thinking about testing it out on a 10 gallon i have laying around with one cracked pane anyways. If i break it im out nothing.
    What size should i get for hole saw and also what size/type of overflow should i get. can i just do an elbow and put a screen on it to keep fish from going down?
    also how many should i do. I am guessing a 1-1/2" bulkhead should be good but not for sure. The current plan is to take her 55 gallon tank return which put out 300-500gph after head loss and add my 30 gallon tanks return which puts out 300 ish gph after head loss on the tank. what would you all suggest?
     
  8. AJ

    AJ Inactive User

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    Drilling a tank is not hard.  Let the hole saw do the work.  Exactly like they said with plumbers putty and water.  About the only thing that I would add is to put an old  towel on the inside of the tank to catch any glass dust and the glass that you cut out.  Use the clean part of the towel to wipe the glass dust off of the tank and then throw the towel away.  I also throw the used plumbers putty away because it has that glass dust on it.  The stuff it cheap enough that you don't need to worry about keeping it around for reuse.
    Now, for the overflow box.  Can you use a bulkhead and an elbow? Yes.  Is it best?  No.  Depending on the amount of flow that you plan to have through your overflow, (common for that size is 600 GPH max) that will tell you the size of hole you need to drill and the size of overflow you need.  Go and use Reef Central's Drain/Overflow size calculator here - http://www.reefcentral.com/index.php/drainoverflow-size-calc   At 600 GPH, you'll see that you need a minimum of a 1" drain (I would recommend rounding up) and 9" of linear overflow surface.  Basically what that means is that no matter what shape your overflow is, there should be 9 linear inches from the point where it touches the glass on one side to the other point where it touches the glass.  This is for optimal surface skimming.  Let me know if this doesn't make sense.
    --AJ
     
  9. Bud Loves Bacon Website Team Board of Directors Leadership Team GIRS Member Vendor

    West Des Moines, IA
    Ratings:
    +1,821 / 14 / -0
    I personally do not like the RC calculator. It tells you nothing! What I was hoping for is something that tells me how many teeth at 1/4" width I would need to get X amount of flow. The RC calculator just tells you "you need 17 inches" or something like that. Well thanks a lot, 17 inches of what at what depth?
    The answer is a fluid dynamics problem, and the flow rate through the top of an overflow box depends on the depth and width of the slots and the water height on them. Thankfully, one of the MEs in our firm provided me with a fluid dynamics book that was like 50 years old, and the calculation I worked out was confirmed by James Steele of Envision Acrylics.
    Any overflow box is dependent on the equation:
    Q = 2/3 * H^(1.5) *L * sqrt(2g)
    After some simplification and conversion of units to get Q in GPH and it becomes
    Q = 288 * C * L * H^(1.5)
    Where H=height of water over the lowest point in the notch, L=total linear length of the overflow (either the length of a weir, or the sum of the widths of all the slots), and C is a coefficient of friction / surface tension.
    If you have 1/4" slots, C=0.55. If it's a weir (no slots) then C=1.0.
    So if you have a 9" wide overflow box with 1/4" wide slots every 1/2", you have 4.5" of slots (L), and if those slots are 1" deep (H), then Q = 288 * .55 * 4.5 * 1 = 712.8 GPH
    If the water height is 3/4", then Q = 463 GPH.
    If it's a 9" wide weir (like a 'Calfo' coast-to-coast overflow, no slots, just a fence) then Q = 2592 GPH at 1" (yes), 1680 GPH at 3/4", 916 at 1/2"
    It's not as simple as RC makes it.
     
  10. Bud Loves Bacon Website Team Board of Directors Leadership Team GIRS Member Vendor

    West Des Moines, IA
    Ratings:
    +1,821 / 14 / -0
    Sorry for going all totally geek like that.
     
  11. Nik Experienced Reefkeeper

    Windsor Heights
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    +13 / 0 / -0
    Trying to be like Andy..... LOL
     
  12. Bud Loves Bacon Website Team Board of Directors Leadership Team GIRS Member Vendor

    West Des Moines, IA
    Ratings:
    +1,821 / 14 / -0
    hmmm...is that a compliment? /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif
     
  13. Sponge Expert Reefkeeper Vendor

    Marshalltown, IA
    Ratings:
    +233 / 1 / -0
    Way to go Bud!

    If it was easy, there wouldn't be a calculator and Bud, you'd be even busier! ;=0) lol
     
  14. snowman82

    snowman82 Experienced Reefkeeper

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    i have had the elbow with strainer type of overflow and the glass-holes one and i personally like the glass holes one better.  Granted it cost more, but it looked alot better and did a better job.  I think your money would be well spend there.
     
  15. Cipher43

    Cipher43

    65
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    Thanks AJ and bud. Gotta love all the info everyone has given. That makes me feel better about doing the holes in the tank. Any brand of overflow you all like better. I know the one i hear the most about is glass-holes.com but does anyone have a better one or others i should consider?
     

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