External herbie overflow.. glass thickness?

[JDigital]

I'm looking to add an External Herbie overflow box to my tank after some discussions with a few people regarding sumps (which I had originally planned on omitting from my build)

How thick does the glass need to be?

I have some left over glass that originally came with the tank for a glass top... but it is prolly only 5-6mm thick. Would this be thick enough or will I have to look else where for thicker glass? (and how thick?)

TIA
Josh

[NanoReefWanabe]

how big an overflow?

6mm glass is fairly thick...should be good or most...also depneds on how many holes your going to drill in it..

[JDigital]

I'm looking at about 9" tall (half my tank height), 16-18" wide, and 6" deep.

Two 1 or 1.5" holes in the bottom for the drain lines.

[BeanAnimal]

The overflow does not need to be that deep.

I would also suggest that you look at my silent overflow build. It is similar to the herbie overflow but adds significant fail-safe functionality and is much more stable with regard to adjustment bandwidth.

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

Here is the link to the RC thread on the subject. http://www.reefcentral.com/forums/showthread.php?threadid=1310585

The wider the overflow box, the better it will surface skim. You should maximize the width if you can.

[paulyl61]

My overflow is a DIY Herbie about the same size as you are planning and I love it, VERY easy to adjust, and COMPLETLY silent. 1/4 inch glass should be fine with your dimensions. Good luck

[JDigital]

<a href=showthread.php?s=&postid=12710209#post12710209 target=_blank>Originally posted</a> by BeanAnimal
The overflow does not need to be that deep.

I would also suggest that you look at my silent overflow build. It is similar to the herbie overflow but adds significant fail-safe functionality and is much more stable with regard to adjustment bandwidth.

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

Here is the link to the RC thread on the subject. http://www.reefcentral.com/forums/showthread.php?threadid=1310585

The wider the overflow box, the better it will surface skim. You should maximize the width if you can.

Hmm i like that idea/design too.. would rather have the overflow inside the tank rather than externally (to save on space mostly), plus I would be able to use acrylic and get teeth cut into it, correct?

[NanoReefWanabe]

<a href=showthread.php?s=&postid=12712643#post12712643 target=_blank>Originally posted</a> by JDigital
Hmm i like that idea/design too.. would rather have the overflow inside the tank rather than externally (to save on space mostly), plus I would be able to use acrylic and get teeth cut into it, correct?

mostly a preference thing...there is no need for teeth...it will drain as effectively if not more so without teeth...plus you dont have to clean the teeth out..

i prefer external for many reasons...
1: leaves more room in tank for fish and corals.
2: dosent block any light in you tank, nor does it limit bulb configuration.
3:those who cant drill the bottom of their tanks can drill the
bottom of the overflow= less elbows etc. therefore less restrictions
4: you cant see it
5: i see no advantage to using acrylic over glass...short of cutting teeth which you dont need.

[BeanAnimal]

JDigital, the principle will work on an internal or external overflow.

Teeth greatly reduce surface skimming.

I also much prefer an external overflow. The next tank will have one.

[NanoReefWanabe]

<a href=showthread.php?s=&postid=12712643#post12712643 target=_blank>Originally posted</a> by JDigital
Hmm i like that idea/design too.. would rather have the overflow inside the tank rather than externally (to save on space mostly),

not sure how much space it would really save...

you will likely have to go through the back of the tank with a bulk head and an elbow, so i guess you might save and inch or two...it would really depend on how deep (front to back) you made your external overflow..my 1.5" bulkhead and elbow sit about 3.5" out from the back of my tank, i would like to think you could easily get away with and external overflow in the neighbourhood of 4" and still drill for 1.5" bulkheads..the weight and pressure on the overflow box is far less then that of a hole in the back of a full tank, so you can drill closer to the edge.

IF you can drill the bottom of the tank then yes it would save space OUTSIDE the tank

currently have internal overflow myself...i cant wait for the next tank to have an external..

[alpine]

Off topic but who is Herbie?I seriously dont remember anyone named Herbie coming up with the idea of external overflows.

[Kewlworm]

I had just built a external overflow a little longer than yours 23"x9"x4" and I used 3/8" thick glass. I think it's overkill, but I had the glass laying around so. I would suggest 1/4" for your size.

[NanoReefWanabe]

<a href=showthread.php?s=&postid=12718063#post12718063 target=_blank>Originally posted</a> by alpine
Off topic but who is Herbie?I seriously dont remember anyone named Herbie coming up with the idea of external overflows.

i believe he is referring to the standpipe design and not the overflow box itself...

[JDigital]

I still have the opportunity to make it external. I picked up a sheet of acrylic last night and cut the pieces for my overflow.

http://img.photobucket.com/albums/v314/JDigital/54G%20Reef%20Tank/4pc.jpg

It is 6"Tx4"Dx24"L

I am a bit confused though now.... Doesn't an internal overflow provide alot more surface skimming (not going with teeth anymore) compared to 2-3 bulkheads drilled for the external??

:confused:

[NanoReefWanabe]

you dont drill hoes for external...you cut in a weir...(large slot across the back)

you CANT make an external acrylic overflow on a glass tank...will not hold on to the backof the tank...

[JDigital]

<a href=showthread.php?s=&postid=12719620#post12719620 target=_blank>Originally posted</a> by NanoReefWanabe
you dont drill hoes for external...you cut in a weir...(large slot across the back)

you CANT make an external acrylic overflow on a glass tank...will not hold on to the backof the tank...

:eek: ... So i guess that makes my choice pretty easy... Internal it is... Or does that not work either?:confused:

[Megalodon]

I'm doing an external overflow box with glass the same thickness as the tank.

I'm drilling the tank, not using a weir, to get the water into the overflow box. It will be using upturned 90-degree elbows in order to surface skim.

I'd prefer a weir but I'm not advanced enough to attempt it.

[Kewlworm]

Hey, Maga, do it man! I thought it was hard too, but after reading alot of it...I went for it and I gotta say I am very happy with the result. Cut the weir and the drain holes...would never go back to drilling again.

[NanoReefWanabe]

acrylic should be fine for internal overflow in a glass tank...the water pressure would keep it from falling off..mine is acrylic.

as for a weir...it is fairly easy...

drill two holes on the same level...take your dremel and cut the lines to thetop edge of the tank...then with a glass cutter score the line between the bottom of the two holes..snap it off..sand it down and your pretty much done...

[Kewlworm]

Hey, Nano, I was gonna do that, but I was afraid it might crack because the glass was 1/4" and didn't want to risk it. I would def. do that on my 20g L next tho. :)

[X men]

<a href=showthread.php?s=&postid=12716141#post12716141 target=_blank>Originally posted</a> by BeanAnimal
JDigital, the principle will work on an internal or external overflow.

Teeth greatly reduce surface skimming.

I also much prefer an external overflow. The next tank will have one.


External ? :-) Yes !!! I surely hope that you will make an as beautifull sketchup on this design, as on your internal overflow system. Will this be something for the next few weeks, or is it a long term project ?

[Megalodon]

<a href=showthread.php?s=&postid=12721384#post12721384 target=_blank>Originally posted</a> by Kewlworm
Hey, Maga, do it man! I thought it was hard too, but after reading alot of it...I went for it and I gotta say I am very happy with the result. Cut the weir and the drain holes...would never go back to drilling again. Doesn't the weir cut into the black tank rim? This is what I'm most concerned about.

[BeanAnimal]

<a href=showthread.php?s=&postid=12726923#post12726923 target=_blank>Originally posted</a> by X men
External ? :-) Yes !!! I surely hope that you will make an as beautifull sketchup on this design, as on your internal overflow system. Will this be something for the next few weeks, or is it a long term project ?

No plans to upgrade anytime soon. I have too many other porjects to complete.

FWIW, I can't stand sketchup, it is one of the worst programs I have ever played with. It does not use any standard CAD or Drawing conventions and the 3d tools (solids manipulation) are almost unusable. It just takes way too much effort to create cut holes in faces or solids, join faces or solids and otherwise create anything usebale. I use Autocad for my drawing, but there are plenty of good cheap CAD and 3D drawing programs out there.