DIY overflow, coast to coast style!

Discussion in 'DIY' started by sfsuphysics, Jul 27, 2006.

  1. sfsuphysics

    sfsuphysics Supporting Member

    Well ok not really, I'm only going from Sacramento to Philly :)

    After not liking the overflows I made for my 100g long tank, for once too much flow they can't handle and second they kind leak so that in a power outage they really won't work very well. So contemplating what I could do I had to try to figure out what to do with a tank that I just can not empty completely.

    So that leaves very few options.

    I can't really get inside it to glue in an overflow so next best thing, I'll glue it to the outside! I did a exterior overflow on a glass tank (much smaller slot cut) and I like it so much I want to do one on this. Problem you might ask is acrylic isn't cheap! Well actually it is. Taps Plastic, scrap bin, got 2 pieces of acrylic one was .220 inches the other was .25inches thick, and I managed to cut a series of pieces and glue them together and use scrap to brace the seams and VIOLA! 5 feet(edit:not inches) long overflow! The overflow is 4" wide and 4" tall, but that's more than enough.

    Haven't installed it yet waiting for help on that, so that'll get done sometime next week. But the plan is to drain a buttload (unit of measurement) of water, then set up a guide whoop out the rotozip, and cut a series of slots in the back (probably 3 or 4). Then glue the thing on, put all the applicable braces, refill with water to near the top (wait 24 hrs for the stuff to cure) then drill and pipe and I'm ret to go! I don't want to do "teeth" because there's too much effort to have a guide to get nice and straight teeth (which would look way janky if you get them crooked), I can always use egg-crate or something to block it from travellers.

    Now I miscalculated by a fraction of an inch for the end pieces (actually I didn't measure at all, I was just hoping that they were bigger and I could cut them down). So I actually have a little lip (almost like a calfo style overflow! :)). But it's on the back of the tank so big whoop if it's not flawless in look.

    Total cost, scrap pieces $4.50 & $6.25 respectively, weldon #16 $4 (thicker stuff), Weldon #liquid stuff (already had it). Total cost a little over $15.

    I'll follow up after I get it attached.
  2. Thales

    Thales Past President

  3. sfsuphysics

    sfsuphysics Supporting Member

    Ok, I'm finished!

    Now I did something that only those with mad acrylic skills should attempt to do! I did all the modifications to a tank that was mostly full with water! Also doing this sort of thing with a helper is always good, my girlfriend was a good helper I gave her a net and told her to fish out the acrylic shavings that were bound to be in the tank.

    Now while I don't have any step by step photos just the finished product it wasn't terribly hard. I simply put a couple 2x4s along the length of the tank and braced them so that if there was any bowing it'd reduce that. Weld-On #16 is a great product, it has a bit of thickened consistancy so you can do vertical work and also it makes filling it imperfections a snap. Basically chopped out 3 slots, I didn't want to completely butcher the back of the tank I'm sure there is a bit of structural support that the top is providing and I didn't want to completely remove it.

    Used the acrylic cement to mount it, which basically added a brace almost the entire length of the tank, had to use a 2x4 with clamps to make it touch the back of the tank (it was bowing, so I had to unbow it :)). Let it cure for 24 hours, noticed my holes were a tad too large, but I'd rather have too large than too small, so after seeing how much flow the pump was giving I got a smokey colored acrylic (looks more transparent in the pictures) to put a nice line along the back so the water cascades over in a very similar fashion to those edgeless tanks rather than waterfalling over (more violent).

    Anyways enough jibber jabber, here's some pics.

    Here's the left side of the tank, I put in 2-1.5in drains, although only one is needed and currently plumbed, I just capped the other one until I need it (maybe down the road for a surge or just as an extra drain for precautions). I put a piece of xenia in there to see if it'd grow any.. but I doubt it'll do good in the long term since it's not that deep in there.

    Here's the same side just at an elevated angle, this is what I meant by enough room so that you get an effect like the edgeless tanks, water is pouring over and coming straight down the side rather than shooting out the slots.

    Right side.. this side has the drain on it that's plumbed outside.

    From the back, a picture of my lumikearc peaking in :) Since my ocean motion was along the back it no longer fit, so rather than worrying too much about finding a way to make it fit (I know how everyone loved the pipes in the tank). I'm doing with out it until I get time to drain the tank down and drill holes for my bulkheads in the back so I can use loclines and get away from the constant ridicule of my PVC in the tank, then probably just have the sump return be a straight shot into the tank.

    The inside of the overflow, here you can see the smokey glass. Middle section.

    Right side (that's the only pvc left in :p).

    Left side

    Best thing about removing the internal overflows is now I have a crapload more space, and the quick rearrangements made room for more stuff!
  4. GreshamH

    GreshamH Guest

    Hope you glued below the flame polished edges :D Nice though, looks good!!
  5. Elite

    Elite Guest

    Ain't you worry about snail getting in there?
  6. sfsuphysics

    sfsuphysics Supporting Member

    What do you mean? I did glue in little triangle shaped braces under the whole length of it if that's what you mean.

    Not really, snails made it over my last overflow (no teeth) and some wound up in my sump, no big deal really, not to mention the slits really aren't that large a hole to allow much through except water.
  7. GreshamH

    GreshamH Guest

    Is your display tank a production model? If so, 99 out 100, the edges are flame polished. gluing to a flame polished edge, will definitly lead to crazy, and worse ;)
  8. sfsuphysics

    sfsuphysics Supporting Member

    I don't know about the tank, but I didn't glue to the edges of the tank, I glued to the back of the tank (ok there's a very slight edge near the top on either side where 1/4" is glued), the back is black so I doubt they'd flame polish the back, and the acrylic I used is tap plastic scraps so it hasn't been flamed.
  9. bareefers

    bareefers BOD

    I can see you cut horizontal slots. Do you have any funky bowing around that area? Sounds like you are cool with being a little sketchy - is there anything about the cutout that has you a little worried?

    I'm thinking of cutting a slot like yours. I've never had a slotted tank though, so I don't know of any unexpected pitfalls. I would assume however that a big old box glued on the back of the tank would really beef it up.

    What are the dimensions of the cutouts and how much water are you putting through there? How high does it "back up" above the overflow?

    And I always wanted to do major work on a tank that was filled!

  10. sfsuphysics

    sfsuphysics Supporting Member

    Yup horizontal slots, I know the standard is "teeth" for protecting against fish/snails but I really don't care for that look not to mention you about halve your total potential flow due to teeth (more so infact due to frictional effects of water against the teeth). Being as I did all the cutting with the tank still full of water (3/4 full) I was worried about potential bowing and the effectiveness of the "euro bracing" or whatever they call the top piece of acrylic that is called if it's not euro style, which is why I didn't cut one long slot along the entire back because for that I knew there might be issues.

    You're right thought a big ol box glued to the back does beef it up against bowing, you're literally putting a quarter inch thick "i beam" type brace along nearly the entire back, as long as it's glued and secured that thing is not going to bow at all. Although that is something that you should consider, if you do it with an empty tank then it's not a problem you get it all nice and secure and glue and wait until it's cured up etc, having water in the tank though already makes it bow, not to mention I couldn't exactly wait an entire week to cure, luckily the stuff claims to cure within 24 hours, but it's really something that cures beyond that time frame, so I left it without anything for 24 hours and clamped up with 2x4s and monster "quick grips" to hold it from bowing while the glue dried/cured.

    The only issue is I think I screwed up on is the size of the slots vertically, I made them WAY too large. I honestly expected the water to back up a little further than it did, but the problem is I knew I wouldn't have any room to work if the overflow was already in, so I figured I could always glue on some acrylic to make the holes smaller after the fact.

    The pump I'm using as a return is a Rio HF20 which is 1290gph at zero head, but it's at a head height of about 2-3 feet, and has a few turns to go through with my oceans motion oscillation device, but if i had to guess I'd say 1000gph is going through there. The two slots on the sides are about 12" long, and the one in the center is 20" long. The water itself only gets maybe 1/4" above slot's bottom, it's really just distributed all over such that water just hugs the acrylic down into the external box so that it's not spilling over (and hence no splashing either).
  11. Vincerama2

    Vincerama2 Evil Overlord

    I'm not sure if I missed it in a previous post, but how did you go about cutting the slots? My first instinct would be to drill a hole, then use a straight router bit, with an edge guide on the router? Or did you drill holes and use a jig saw, then clean up with a router?

    I'm thinking of doing the same thing. (I saw it on one of Qwiv's tank too). I inherited a 100g acrylic tank that will require a fair amount of buffing, but also has the big braced top (not much open space there at all, might end up as a FO tank!) so putting in interneal overflows are going to be much more work than doing what you did.

    Nicely done!

  12. sfsuphysics

    sfsuphysics Supporting Member

    I just plunged the router bit into the acrylic.. and used a guide to make it straight (for the most part)... I ended up making the hole too tall, so I simply glued in a piece of smokey acrylic inside to shorten the hole slot (I thought the pump was going to push in too much water which I forgot to carry a 1 or something because I way overestimated how much flow would go in :)).

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