Cutting a slot for an overflow in back of glass tank?
 

I just bought an awesome half-cylinder tank called the Marineland Half-Moon 30g. It is 27" long by 14" wide by 28" tall and made out of nice thick glass. I would like to cut a slot approximately 12" long by 1/4" tall to allow water to overflow into a glass sump-like compartment that I would build onto the back of the aquarium.

So what's the best way to go about cutting this slot? And how close to the top of the tank could I reasonably put it? (It's frameless on the top). I have a dremel tool, but would be willing to buy whatever I would need to do this, and have successfully cut several glass holes with diamond tipped bits in the past several years.

I am interested to see if this is even possible.

Pife,

Such things are done prior to any other fabrication being done. That way you only lose raw materials, not a finished product. The best method, for longevity of the glass, is using a Techni. That is not something that folks will have in their garage, nor are they likely to buy one for notching a tank. CNC waterjet @ $100,000 +++. With enough time, it can be done by hand, but the results are dismal at best, and still need professional finishing, to insure stress fracturing is very minimal, or not present at all.

It is best to refer such things to professional glass fabrication shops for assessment as to practicality, particularly when dealing with a finished product.

Take it too a glass shop, and see what they can do for you!

I've wondered about this as well. How deep do you want to make the cut? wherever it is will determine the height of water in your display. I would try a drill press with your diamond hole saw to make the beginning and end of the slot. The corners should be round to reduce stress. As for the center I'm not sure that hand tools will work very well, but slow, careful work with diamond cutting blade on a small angle grinder might work. Post pics if you do it!

I'd do it with a circular saw and a diamond blade with plenty of water. I would drill small relief holes at the beginning and end of the cut. The saw is then left with the depth lock open and is allowed to slowly enter the cut, plunging, then is locked down right at full penetration, so not to wonder or bind. You will have to decide if cutting the trim away is a structural risk worth taking. Another way of doing this is with diamond dremmel type tool: again with plenty of water, working wet and slowly you can etch your way through working the entire cut little by little through the glass.

This is the do it your self section; it seems people have missed that point. Like any do it yourself project things sometimes go wrong. If you are not comfortable working with tools please don't attempt doing things like this. $10k glass cutting tools have not been around as long as glass which people started cutting very thick peices of into intricate shapes long before UNCLE was born. Maybe research how glass was cut in a mid evil or gothic cathedral. I'm sure there are other ways than the ones I described.

The first time I saw a circular saw used was on the late Greg Scheimer's tank. Anyone who remembers Greg's advice about drilling might know how he felt about drilling holes in tanks below where one would be comfortable losing all the water to when it leaks. Greg's tank was moved in 5 peices and reassembled. I believe Peter was using the bottom for the rear overflow and cutting a similar slot as the op; the bottom was tempered! Panels were moved and another new one ordered, but the cut was performed the same way. Peter is a high end trim carpenter and very good with tools.

I might have to buy one of these:


http://www.amazon.com/DEWALT-DWC860W.../dp/B003BVW5NU

if someone does this I REALLY WANT A VIDEO... i just dont see it ending well honestly..

This is cool - was this around Rochester somewhere?

With the right blade, water cooling, and a straight guide, cutting thick glass is simple. That being said, I would do some practice first.

It was in the Hudson Valley. I've done it several times with my slide saw, but that was in fabrication mode with smaller panes.

I had things a wee bit off; the bottom blew when drilling. The cutting is all the same, and starts around page 4-6:
http://hvreef.org/yabb/index.php?topic=11406.80

:lol: I'm with ya! Show me the video.

Instead of something so difficult why not just drill a series of holes to do the same function.

Or would it be possible to install an internal overflow box connected to an external box via a couple bulkheads? That would provide you with something with a higher chance of success and would likely be more structurally sound.

I've cut a 1" wide x 9" long slot on the short side of my 40 Breeder. External box installed with silicone. I'll post a few pics with a OP request.

Awesome build! All of that glass cutting makes my little project look like nothing by comparison.


I had considered one of these, but the lack of ability to control the speed concerns me! Would much rather grind away slowly than at 11k rpm!

I don't see this as having to be any riskier than cutting a hole for an overflow. With all of the successful examples on google, where are you getting the "dismal at best" from?

What do you guys think of one of these attached to my dremel:

http://www.amazon.com/Dremel-EZ545-2...0XHBCPH8JBKCWS

I've used it for my sump and it worked pretty well. Takes time obviously, but it worked. If you want nice pretty cuts you'll need to really take your time.

Why dont you just disassemble the tank, cut the top inch off the back glass and reassemble attaching your external overflow to the back?

+1

It can be done. This is 8" long by 1" deep. One of these on each side of a 48" tank. I did this with a dremel.
http://img.photobucket.com/albums/v1...g?t=1424741681

It can be done. That does not mean you should be doing it by hand. I addressed that in my original post.

Hawk, apparently you SHOULD have used a $100,000 water jet machine.

That's not exactly all Uncle said. He recommended going to a pro. Making the cut is one thing, doing it so it won't fail later is quite another.

It would be bad enough to loose a new tank when cutting but it would be much worse to loose the tank when full of water inside your house!