Calfo Style Overflow boxes

Doesn't the actual bulkhead need to be able to fit in the internal overflow box? Aren't they long.

Secondly, i wasn't planning on using elbows in the box. Are they strongly recommended?
 
^ Would an elbow be neeccesary in a low flow box with an external durso? Im trying to minimize the space taken up in the dsplay, and only need a little flow through the sump.
 
You want an inch from the top of the water for the water to drop into the box.....

the depth of the box IMO you want as absolutely shallow as possible while still being able to accomplish what is needed inside the box. I.E. silencing and the water still dropping just enough to be surface skimming
 
Well, if you roundover the top edge of the overflow, the water will actually flow very quietly down the side of the overflow box as long as you're not trying to force way too much water over the edge. I'm flowing about 900gph over 3 feet of overflow, and it drops a good 7" into the overflow box and it's totally silent. One reason to make the box slightly deeper is that it gives you the abillity to enclose the overflow box. With dursos and a very shallow box it might be hard to keep everything enclosed.
 
I see, thanks guys. Should I leave some space in the width of the box to allow elbows if needed. I would rather have a box that is 2.5" wide rather than 4" obviously but I would hate to regret not having the extra room in the long run.
 
You want to be able to reach into it relatively easily, but other than that I don't see any need to have it wider than a couple inches. Oh, except the very outside flange of your bulkheads. I used the sch80 Haywards on mine and they've got a pretty bulky (a good thing) flange. They definitely took up more width than I expected, I just barely had enough room.

That's one of the nice things about a long overflow box though, any elbows for dursos or anything like that can easily be turned sideways minimizing the box depth and utilizing it's length.
 
Also, to answer a question about the roundover I mentioned that helps quiet water flow:

First of all my tank's back wall is 1/2" acrylic. I cut a normal notch out for the basic outline of the overflow. To create the roundover I used a 45 degree chamfer bit with a bearing guide on either side of this notch (as in, both sides of the sheet of acrylic). On each side I just went about 1/3 of the way through the material, this way the original notch provided the guide for the bearing of the chamfer bit. To make the transition smoother, I was pretty aggressive with the micromesh while polishing this particular edge. So, it's not a true roundover, but it left me with a very straight, very level overflow.

If it weren't for the fact that I wanted material touching the crossbrace, and material touching the eurobrace at either end of the back wall, it would have been much easier to just toss the sheet of acrylic onto a big router table and use a 1/2" roundover bit to get a level edge on the overflow. However, after cutting the initial notch I was able to use the chamfer bit and a smaller router to handshape the ends of the overflows (where they contact the tank's top). It just seemed easier to me than trying to control the whole sheet of acrylic on the router table, especially for touchy finish work.
 
<a href=showthread.php?s=&postid=10791713#post10791713 target=_blank>Originally posted</a> by xtm
I like your concept.. maybe you should patent it ;) I am strongly considering it for my eurobraced acrylic tank where a 'traditional' overflow box is not going to work.

My tank has eurobracing all around the rim and if I put the regular overflow box, then I cannot adjust the durso anymore since the eurobrace is blocking it. This is where the Flyyyguy Overflow comes in. I will stretch out a 1" diameter PVC across the 4-FT tank, a cut will be made on top, make some teeth and that will be my overflow! No bulky overflow boxes, no cutting acrylic, and it's less obstrusive and above all - adjustable! :D It's also easier to clean.

My biggest concern about the Flyyyguy Overflow is the sloshing effect, since this is very similar to a standpipe. I've used a standpipe before and even with airline tubing it's still difficult to achieve zero noise. It would slosh every hour or so..

I will test one out and let you guys know.
Click to expand...

I really like this concept too and was thinking of doing it myself but need more input on it. So have you tested it yet? Is there another way to cut the pipe besides using the table saw? thanks

mike
 
Well this thread convinced me to do a calfo overflow as well I just got the glass siliconed in on friday and trimmed it up a bit today! here are some pics of it installed but not trimmed up! Thankx

Eric

<a href="http://s238.photobucket.com/albums/ff120/ebrabender/?action=view&current=100_0008.jpg" target="_blank"><img src="http://i238.photobucket.com/albums/ff120/ebrabender/100_0008.jpg" border="0" alt="Photobucket"></a>

<a href="http://s238.photobucket.com/albums/ff120/ebrabender/?action=view&current=100_0002-1.jpg" target="_blank"><img src="http://i238.photobucket.com/albums/ff120/ebrabender/100_0002-1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s238.photobucket.com/albums/ff120/ebrabender/?action=view&current=100_0005.jpg" target="_blank"><img src="http://i238.photobucket.com/albums/ff120/ebrabender/100_0005.jpg" border="0" alt="Photobucket"></a>
 
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