Step-by-Step: Drilling Holes in Your Glass Tank for Bulkheads

[Maeda]

Thanks to the thread starter and those others that attempted this.



6 holes 0 problems.

[Home_Depot]

I want to get rid of my HOB overflow but I do not want to yake down my tank. Can you drill holes with water still in it if you drop the water down a ways???

[BigSkyBart]

Originally posted by Home_Depot
I want to get rid of my HOB overflow but I do not want to yake down my tank. Can you drill holes with water still in it if you drop the water down a ways???

To Reef Central

I think I read somewhere back several pages in this thread that someone did that, didn't sound too difficult, but there is some risk involved. I would practice my glass drilling skills first.
GOOD LUCK!

WOOOOOHOOOO!! I got to give a welcome to a "1" poster

[Home_Depot]

Thanks for the info and the welcome!!

[spmedi]

Ok so I going to give this whole SW thing a try. I have an extra closet below my L-shaped stairs that I and going to use to install a tank into the wall in my foyer. It gives me about a 4x4 area with a little more space below the stairs for other storage. (My ice maker rough-in sit in their as well...do i smell a RO/DI hookup coming?) Anyway the tank had to be 36" to fit so I chose a 40 gallon breeder AGA. I could have went w/ a 65 wide but i need some room to move around.

I have a 20gl long to set below the 40 for a sump/fuge. I plan to just make this a FOWLR for now.

I have about a 25in tall skimmer w/ a 650gph pump. I also have a 850gph pump and was thinking about using it for a closed loop.
I ordered a SCWD about 4 1" bulkheads, 6 3/4" bulkhead, 4 u-tubes. (i like to get extras).

I plan to orger glass for my sump and an overflow. My question is what is the best way to make my overflow and how should I setup the closed loop. Mot much of the engineer type.

Any other suggestions would be greatly appreciated as well.

(I have not order the bits yet until i get my bulkheads in, but i do plan to drill it myself. i got a little 2.5 gallon to practice on)

[Grace's Dad]

Dumb Question?
Is there an attachment for your drill and the hole saw bits?
My 60mm bit is too large to fit in both a Dewalt cordless and Black and Decker corded drill.
My 45mm bit will fit in both but the Dewalt wont grip it tightly and kind of pushes it out, makes it uneven... could be why Superorb on pg 4&5 thought he had untrue bits.

So is there an attachement I can get?
I'd really like to use the Dewalt because it has the slower speed, and I'd like to be able to use my larger bit.

[swedish steel]

All my hole saws came from Lau, in Hong Kong, and even the 85mm fit in my 14 volt DeWalt. Perhaps there is an issue with your chuck or the hole saws you bought have quite a large diameter shaft requiring a 1 inch drill to get a chuck large enough to work.

[Spuds725]

Originally posted by Grace's Dad


So is there an attachement I can get?
I'd really like to use the Dewalt because it has the slower speed, and I'd like to be able to use my larger bit.

This is a keyless chuck adapter.. I didn't look real hard but you should be able to find a keyed chuck adapter...

http://www.toolbarn.com/product/makita/7630977-A/

do you know the shank size of your hole saws??

It might be cheaper to get a new drill

[Grace's Dad]

checked this morning, both drills are 3/8". Lau states both shank sizes to be 10mm, must mean length because the 60 shank is definately thicker than the 45.

[AquaDiva]

This is a great thread...and very timely for me.

Has anybody found a site/thread which details how many and what size hole you can drill before compromising the integrity of the tank?

I am curious how one figures out how many holes and what size and where you can put them for a given size tank. I imagine hole placement would be different for a 29 vs a 55 vs a 210.

[DHyslop]

Originally posted by AquaDiva
This is a great thread...and very timely for me.

Has anybody found a site/thread which details how many and what size hole you can drill before compromising the integrity of the tank?

I think someone would really need to talk to an engineer to get anything definitive like that. There are guidelines that are commonly posted (such as staying one diameter away from the edge of the glass, etc.) but these are just rules of thumb.

I think most systems can be set up without needing enough holes to make it dangerous--unless its a 500 gallon tank, do you really need ten bulkheads for a closed loop?

Dan

[phallock]

Originally posted by poopsko24
I want to take off my hang on overflow box and drill the back top of my tank. I will drill for two 1 1/2" bulkheads, how far aprat from one another do I have to be on these ? And from that I woul like to make up the smallest possible glass overflow box, i will silicone it to the inside, but what size should i be if i plan on roughly 1200 gph going through ? I would like to do something like 12" L x 4" or 5" W and I'm not too sure at all if the height of it will matter ? I was thinking just enough to cover the bulkheads, is there a certain height I need to be? thanx all.

Was just reading through this thread and thought I'd respond to this with some observations from personal experience with a horizontal overflow:

1) If you're going to do a Durso style, with 90 elbows in your overflow box, I'd recommend a slip bulkhead on the flange side and slip/street 90's. Mine are threaded and I need extra space to seat the 90 before I twist it in.

2) You want #1 because the wider your box sticks out, the more it ptentially affects your lighting. I'm finding this out the hard way. I made mine 4" wide, and now will have difficulty fitting a 6 light T5 retro in the space between the front of the tank and the overflow.

If I had to do over again (and I just might) I'd look at how much clearance I'd need for a slip bulkhead (flange side) and elbow, then make the box just wide enough to accommodate that. 90's are a pain to thread in an overflow box anyway. Right now I could get way with a 3/4" narrower box, maybe even more with slip fittings.

All that being said, I have 40" of scum-busting skimming "surface" and when you look at the tank from a few feet away, you hardly notice the overflow. It's a great alternative - to me even preferable - for brick owners.

[Conesus_Kid]

Originally posted by phallock
Was just reading through this thread and thought I'd respond to this with some observations from personal experience with a horizontal overflow:

1) If you're going to do a Durso style, with 90 elbows in your overflow box, I'd recommend a slip bulkhead on the flange side and slip/street 90's. Mine are threaded and I need extra space to seat the 90 before I twist it in.

2) You want #1 because the wider your box sticks out, the more it ptentially affects your lighting. I'm finding this out the hard way. I made mine 4" wide, and now will have difficulty fitting a 6 light T5 retro in the space between the front of the tank and the overflow.

If I had to do over again (and I just might) I'd look at how much clearance I'd need for a slip bulkhead (flange side) and elbow, then make the box just wide enough to accommodate that. 90's are a pain to thread in an overflow box anyway. Right now I could get way with a 3/4" narrower box, maybe even more with slip fittings.

All that being said, I have 40" of scum-busting skimming "surface" and when you look at the tank from a few feet away, you hardly notice the overflow. It's a great alternative - to me even preferable - for brick owners.

Is there an advantage to these elbows within the box? Do they cut down on noise? I just picked up a 75 that I'm going to do a similar overflow to yours and was just planning on having the open bulkheads draining to the sump. (I was going to put gutter guard over the top of the overflow to keep out the critters.)

Thanks.

[jman77]

I'm going to put 2 1" bulkheads on my 58 . I've had it with the HOB overflow. I'm going to make two small / narrow overflow boxes and silicone them to the tank where the bulkheads are.

You don't have to make the boxes that wide if you don't plan on putting 90 elbows in the box. The 26 bowfront that i setup like this had a small corner overflow box that was about 1 " & 1/2 and it hangled a good mount of water flow. The inside boxes for the 58 are going to be around 1" wide and 6 inches long.

[aurorahokie]

Just wanted to say "thanks" for this thread! I followed the directions and was successful drilling my 90(3 - 45mm holes for closed loop).

Thanks!
Chip

[jman77]

Auro ...did you use a drill guide ? I'm not sure if i should use one when i drill my tank.... The 45mm hole bit is for what sized bulkhead ?

[phallock]

45mm equates to 1 3/4" - usually the size hole you need for a 1" bulkhead. I didn't use a press, just a cordless 18V drill. Don't try to drill head on at first; tilt the bit to get a groove started before you go to vertical.

As to the 90's on my overflow - I don't have what will be my main return pump yet (probably an Eheim 1262 or Mag 9.5) and I haven't finished the plumbing. When I do, then I'll see if I need the elbows. At present, my main noise problem is the PVC in back, which I'm changing to spa-flex. The overflows have been pretty quiet both ways, but I'm not sure what kind of throughput I have right now with the old Rio 2500 I'm using to test the system. General consensus that I've received is that the 90's will be needed to cut down on noise.

[GoldStripe]

jman77 you may want to use a piece of plywood clamped to your tank to guide the diamond bit. that is what I did on all my holes. I'd never think of doing freehand

[GoldStripe]

Better yet, here's a picture of how I set it up.



Finished product (holes anyway)

[poopsko24]

Originally posted by phallock
Was just reading through this thread and thought I'd respond to this with some observations from personal experience with a horizontal overflow:

1) If you're going to do a Durso style, with 90 elbows in your overflow box, I'd recommend a slip bulkhead on the flange side and slip/street 90's. Mine are threaded and I need extra space to seat the 90 before I twist it in.

2) You want #1 because the wider your box sticks out, the more it ptentially affects your lighting. I'm finding this out the hard way. I made mine 4" wide, and now will have difficulty fitting a 6 light T5 retro in the space between the front of the tank and the overflow.

If I had to do over again (and I just might) I'd look at how much clearance I'd need for a slip bulkhead (flange side) and elbow, then make the box just wide enough to accommodate that. 90's are a pain to thread in an overflow box anyway. Right now I could get way with a 3/4" narrower box, maybe even more with slip fittings.

All that being said, I have 40" of scum-busting skimming "surface" and when you look at the tank from a few feet away, you hardly notice the overflow. It's a great alternative - to me even preferable - for brick owners.

great pics, thanx . Do you need the elbows on the bulkheads ? I was thinking to just put a drain tee on the outside of the tank with a vent on top, then draining to the sump. Iwill silicone my overflow box up today. What should I use to hold up the box when siliconing it to the tank ? I'm not taking the tank off the stand so all my work will be done with the tank on the stand.

[dtaranath]

when I did my overflow, i used two or three 2x4's to hold up the overflow. make sure everything's level when you do it.

and you don't need elbows on the bulkheads, but it will certainly reduce noise.

[poopsko24]

that should work, what about something pushing into it ?

[dtaranath]

Originally posted by poopsko24
that should work, what about something pushing into it ?

I put the two pieces of the calfo together prior to attaching it to the tank. I rested one piece along a wall, and the other on the floor. after the silicone dried, then I rested the completed overflow on the 2x4's in the tank and rested it right up against the back of the tank. I first siliconed the inside, and once that dried, I removed the wood and siliconed the underside.

like everything else in this hobby, patience required.

[GoldStripe]

Just to give a different method, I siliconed the shelf or horizantal piece in the tank and let it dry. I used 2x6's with the bottom corner notched out to keep it off the silicone on the bottom of the tank. I set a piece of plywood across the tops of the 2x6's and then shimmed to get it perfectly level. Then I cut blocks of wood to act as standoffs and to keep it square for the vertical piece. I siliconed from the inside only but I made sure that got on the edge of the glass making contact with the tank. Whichever way you like will work fine. There's more than one way to skin a cat but like Dan said it takes some patience cause silicone is tough to work with.

[tcottle]

Thanks - because of this thread I have sucessfully drilled my first tank. It was scary how easy it was!