Drilling a tank for overflows & returns

[ElijahTurtle]

I just did this last week on my 37 gallon. I used diamond hole saw bits. One is a 45mm hole fit's a 1" slip in bulkhead. & a 40mm fits a 3/4" slip in bulkhead. I still have the loaner bits from the SW forum till the next member calls for them so maybe I'll find a crusty old tank to do some more practice on.
I used a ryobi 18V cordless drill high bit speed & a steady water flow with nearly zero down pressure. Started witgh a slow speed & used some simple plexiglass templates to guide the start of the holes then did the rest free handed at a high bit speed.
I will paint the pvc with krylon fusion to mask it from view. The back of the tank will be painted black as well.

Here's what I've got so far:

The first hole is a little rough, but not a problem, that can't be cured with a little extra silicone.

http://i134.photobucket.com/albums/q83/elijahtturtle/100_1193.jpg

Second hole came out good & clean except for where the template slipped & the bit scratched the glass as I was starting the drill

http://i134.photobucket.com/albums/q83/elijahtturtle/100_1198.jpg

Here's the tank with the bulkheads temporarily set for plumbing refernce while I cut the pvc to fit.

http://i134.photobucket.com/albums/q83/elijahtturtle/100_1203.jpg

Here's the 1" drain with the vent cap set above the rim of the tank.

http://i134.photobucket.com/albums/q83/elijahtturtle/100_1235.jpg
http://i134.photobucket.com/albums/q83/elijahtturtle/100_1234.jpg

In this one you can see the 3/4" return line & the 1" drain.

http://i134.photobucket.com/albums/q83/elijahtturtle/100_1237.jpg

[DiscusD]

I have drilled most all of my tanks any where from 10 to 120 Gallon tanks the larger
thicker glass is much easier since it wont crack as easy. What I do is use plumbers putty and make a ring to fill with water. to make a puddle to keep the glass cool. It's also less of a mess not much water. I mark where I want the hole and start it on that mark at an angle. Once its started then I move the drill so it's straight and drill at a fairly slow speed to keep the heat down. This make sthe daily water changes very easy.

D'Wyatt

[rolloffhill]

Very cool, I don't think I would have tried that...

[ElijahTurtle]

Yeah I tried doing the first hole at a slower speed, gave up on it since it took about 30 minutes to drill the hole. At the rate I had the water running & the amount of pressure I was putting on the drill it never even got close to warm much less hot, and I didn't really get wet either, just my left shoe :confuzeld:. The second hole came out nice and clean, I could see how heat would be a problem on tanks with glass nearing 1/2 thick or more.
I also got less vibration out of the higher speed, maybe with a higher quality drill that is designed with more balance you might not have have that. I had one guy on a SW site recomend using a corded drill which would be more consistent speed wise. Yeah right! Not even with a GFI outlet. I've gotten a handfull of some 110 in the dark before, ain't ever gonna risk that again.:burned:

[DiscusD]

I have used both Kind of drills But with the little puddle of water not that much chance for a shock.
D

[kewlkatdady]

I'd be more scared of shattering the glass than shocking myself.

[AndrewH]

Maybe we should do some looking for broken or really cheap tanks and do a hands on demo for cutting?

OH WAIT... my friend has a chit load of window pains (6" * 9", I think might be 9" x 9"). I'll see about getting some. Hmmm maybe we could do a "silicone" leason too ;)

[ElijahTurtle]

Well I don't have the bits now, I passed them off to the next user in line. But I do believe I wil be buying a set of my own. I enjoyed the whole experience & I have already thought about finding some junk tanks to practice on.

[AndrewH]

How much do the bit go for?

[Vivarium Concepts]

Andrew, the bits from AmeriGlass are pricey, but very good. If you are planning to do more that a couple of holes, I would go with those.

The set from Overstock is cheap (especially with free shipping), but they are only good for 2-3 holes, depending on the glass thickness. It will help to prolong the bit life if you keep it cool, and go slow.
I use an air drill with this drill jig : Amazon.com: Wolfcraft 4525 Drill Guide Attachment for 1/4-Inch or 3/8-Inch Drills: Home Improvement

http://www.shopsmartxpress.com/AmeriGls/AmrDefault.htm?M9a.htm

http://www.overstock.com/Home-Garden/GRIP-5-piece-Diamond-Dust-Hole-Saw-Set/1549352/product.html

[ElijahTurtle]

I'm watching some on eBay that I can get for about $30 shipped to the door.
I want a 45mm, 40mm & a 38mm. These will work for standard 1" & 3/4" bulkheads.

[AndrewH]

45mm = 1.7716535433" = ~1 3/4"
40mm = 1.5748031496" = ~1 9/16"
38mm = 1.4960629921" = ~1 1/2"

That drill guild looks pretty cool. And $30 shipped to the door isn't bad for the bits.

[AndrewH]

Here's (http://www.shopsmartxpress.com/AmeriGls/MAIN.htm) the AmeriGlass prices.

[AndrewH]

I guess the question is, what hole size do you need for each bulkhead size (like 1/2", 3/4", 1", 1 1/4" and 1 1/2")?

[ElijahTurtle]

Depends on the schedule of the bulkhead. I'm not sure what mine are, but schedule 40 PVC fits them I guess they are fairly common.
45mm makes a 1 3/4" hole that fits the 1" bulkhead.
40mm makes a 1 9/16" hole that fits the 3/4" bulkhead (loosely)
I think the 38mm would be just right for the 3/4" bulkhead.

[AndrewH]

So maybe DFWfishbox could get some 38mm and 45mm bits? ($40 and $45 from AmeriGlass)

[ElijahTurtle]

Here's the ones I'm watching on eBay. These are the same bits they have been passing around the DFWMAS for a good while. As for durability, I'm not sure, I don't know how many people have used them, but I know the last guy had them for several weeks & drilled 10-20 holes with them himself.
I think the 60mm is good for a 2" bulkhead.

eBay Dimaond Bits (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320162989576&ssPageName=MERCOSI_VI_ROSI_PR4_PCN_BIX_Stores&refitem=180180052261&itemcount=4&refwidgetloc=closed_view_item&refwidgettype=osi_widget)

[AndrewH]

About $30 shipped, not too bad. (though it seems the AU$10 shipping is to AU, not US)

You buy 'em yet? Doesn't seem like the auction ever ends (at least I don't see the expiration) and they seem to have 98 available.

What brand are they?

[ElijahTurtle]

Yeah I was watching the same auction for the US but it ended. Another one just like it will show up soon. That was the only current one I could find with those 3 bits. I haven't bought them yet. Will wait till I'm "less broke" LOL As if that will ever happen.:hehe:

[AndrewH]

OIC, definitely post a link if you see the American auction pop back up.

[ElijahTurtle]

Yeah I will. I enjoyed it so I plan on drilling the 55 eventually too. So I will need them

[greeneyed]

What are the benefits of drilling a tank as opposed to using an overflow?
I personally would like the tank to be full, so I don't see the lights reflecting off the top of the water.
But I am VERY new to fish keeping, and would like to hear everyones opinions.

[AndrewH]

Drilling = overflow

If the tank isn't drilled you have to have an over the tank overflow box (big, bulky, hard to hide, and also requires a lot of room behind the tank). If you have holes in the tank, you can have a simple box that hides piping and that can be discussed.

Here's a picture of an overflow box hanging on the tank's edge (on the right-hand side)
http://www.aquacrylics.com/75wovinsump.jpg

Here's a picture of a drilled tank's overflow
http://www.wetdryfilter.com/specia4.jpg
and a different version
http://www.wetdryfilter.com/specia9.jpg
and another
http://www.wetdryfilter.com/specia27.jpg

[AndrewH]

I personally would like the tank to be full, so I don't see the lights reflecting off the top of the water.

Basically, if you have a hole in the tank, you can adjust the water level with a few different methods.

1. install an elbow (or a stand pipe if the hole is in the bottom of the tank) to raise the pipe inlet to the top of the tank (allow the tank to be completely full).

2. have the over flow box go all the way to the top and then the cut backs (the "castle top" effect) only go as low as you'd like the water level.

I'm pretty sure there are other methods, but I can't think of them right now.

But if you have the over the tank overflow box, you're limited by the adjustment of that unit. Meaning, there are normally adjustment screws which control how high the interior box sets inside the tank which controls the water level inside the tank. If the unit you have will allow you to adjust the interior box all the way to the top of the tank, then you should be able to have the tank full of water, however if you're unit does not allow the interior box to be adjusted all the way up you'll be limited on the water level to what the unit's adjustment maxs out at. (I hope that make sense).


Also, just so you know you can NOT drill tempered glass :D. The holes have to be cut before the glass is tempered.

[greeneyed]

OK, never had a drilled tank before, so never really thought much about it.
Makes sense now.
Is the overflow box made of acrylic?
Thanks for the explanation.
Knew about tempered glass.

[AndrewH]

OK, never had a drilled tank before, so never really thought much about it.
Makes sense now.

Yeah, I'm having my first drilled tank built right now, so I'm hoping I've done my homework :D.

I had the tank maker cut holes in the back for an overflow and for a return.

My original plan was to setup the tank with a sump, but then I decided to do a canister since I now plan to plant the tank. With both holes, I have lots of options (meaning I can seal off one or both of them if I don't end up using/needing them).

Is the overflow box made of acrylic?

The over the tank's edge ones are made of acrylic (at least I haven't seen any that aren't acrylic), but the in tank overflows can be glass or acrylic. I'm guessing either way would probably cost about the same, or glass a little more expensive.

Thanks for the explanation.
Knew about tempered glass.

You're very welcome.

And that's good, I hope you didn't learn about tempered glass the hard way ;)