Wooden External Overflow Box?

[SkyReef]

3 Gaskets Per Bulkhead: Gaskets Have Arrived!

3 Gaskets Per Bulkhead: Gaskets Have Arrived!

STATUS UPDATE: The extra bulkhead gaskets arrived today by priority mail! Glad to be moving forward on this.

Three gaskets will be used per bulkhead:

(1) on the inside of the aquarium, between the nut and the rear aquarium wall;

(2) in between the aquarium and the wooden overflow box; and

(3) on the inside of the overflow box, at the flange.

I still need to add a few more coats of paint on the wooden overflow box, which will happen this weekend when it's warm. I'll take pictures and post them this weekend. Any thoughts, comments, advice welcomed. Thanks.

 

[torino06]

hey it's coming along nicely! i probably missed it, but why 5 holes? more flow or for support?

 

[SkyReef]

hey it's coming along nicely! i probably missed it, but why 5 holes? more flow or for support?

Thanks, Torino. Essentially, it has to do with flow, not support of the box. The support of the external overflow-box will principally come from wooden-supports below the box, not the bulkheads.

The five holes allow proper "communication" of the water from the internal, overflow-box to the external, overflow-box. Credit for the five-hole design here, including its height and placement, is owed to Uncleof6, who explained the importance of assuring that the water can freely flow from the internal overflow-box to the external overflow-box. He stressed that one should ensure that enough holes are drilled to allow the water to properly "communicate" in this regard. See post at http://www.reefcentral.com/forums/showpost.php?p=20915567&postcount=5306. Originally, I designed fewer holes, but Uncleof6 set me straight here: More holes = more flow.

Thanks.

 

[der_wille_zur_macht]

I would probably skip the gasket under the nut. It's not technically required to remain leakfree (water can "get by" that interface via the nut threads anyways) and having THREE gaskets might create an opportunity for the whole arrangement to be too "soft."

 

[coryjones]

Any good glass store would make u a over low that you could simply silicon to your tank.

 

[SkyReef]

I would probably skip the gasket under the nut. It's not technically required to remain leakfree (water can "get by" that interface via the nut threads anyways) and having THREE gaskets might create an opportunity for the whole arrangement to be too "soft."

Thank you for your response, DerWilleZurMacht. It's very helpful.

The issue I face is a reverse-oriented bulkhead. Please recall that the internal, coast-to-coast overflow-box is skinny by design (i.e., narrow from front to back), to reduce its profile and visual obtrusiveness. As a result of how cramped the space is in the internal overflow box, I cannot insert the entire bulkhead into it, so as to lodge it through the hole. The only way that the bulkhead can be lodged into the hole is from the rear, not the front. Lodging it from the rear, i.e., from the external overflow box to the internal overflow box, causes a reverse-oriented bulkhead.

Thus, with this reverse-oriented bulkhead, the flange side sits in the external overflow box, and the nut side sits in the internal overflow box. My concern in not using a gasket in the internal overflow box is leakage. Has it been your observation that the threaded end at the nut does not benefit from a gasket?

Also, I'm trying to understand your point about the fitting assembly becoming too "soft." I gather that you are saying the assembly needs a hard contact somewhere so that the nut can be screwed more tightly, reducing the chance of leakage. Thus, you seem to be saying that using a third flange to reduce the risk of leakage would actually have the opposite effect.

What are your thoughts about the reverse-oriented bulkhead issue I face, and do I understand your points correctly. Thank you.

 

[SkyReef]

Any good glass store would make u a over low that you could simply silicon to your tank.

Hi, Cory. Thanks for your response. I don't doubt the truth of what you say. Yet, I wanted to make the overflow box, myself. I like DIY projects because I spend way too much time in my attorney life working with words and analysis. I want to work with my hands, to balance things out, in my spare time.

Yet, as chronicled ad nauseum in this thread, the glass-external-overflow-box route didn't work out so well for me. I wanted to find another way. I saw the humor in the truth that, if the Pilgrims could cross the Atlantic in a waterproof, wooden boat, I could make an wooden overflow box waterproof.

So here we are with a thread on a wooden overflow box. I admire the ambition and success of those, like DerWilleZurMacht, who have made wooden aquariums waterproof. I was inspired to try it here. Thanks.

 

[coryjones]

I understand i am sorry for the short reply i was on my phone and it did not show the multiple page thread for some reason. But at the same time just trying to pass some info on to anyone thinking about trying it.

 

[der_wille_zur_macht]

Thank you for your response, DerWilleZurMacht. It's very helpful.

The issue I face is a reverse-oriented bulkhead. Please recall that the internal, coast-to-coast overflow-box is skinny by design (i.e., narrow from front to back), to reduce its profile and visual obtrusiveness. As a result of how cramped the space is in the internal overflow box, I cannot insert the entire bulkhead into it, so as to lodge it through the hole. The only way that the bulkhead can be lodged into the hole is from the rear, not the front. Lodging it from the rear, i.e., from the external overflow box to the internal overflow box, causes a reverse-oriented bulkhead.

Gotcha. I would argue that, technically, there is no such thing as a reverse orientation - as long as there is a gasket on the flange side it's "correct" and will be leak-free. Using the bulkheads to seal two holes introduces a bit of complexity but the same logic applies.

Thus, with this reverse-oriented bulkhead, the flange side sits in the external overflow box, and the nut side sits in the internal overflow box. My concern in not using a gasket in the internal overflow box is leakage. Has it been your observation that the threaded end at the nut does not benefit from a gasket?

As long as the flange is gasketed to whichever surface it's touching, and there's a gasket between the box and the tank, it can not leak (assuming those gaskets are sound). Assume you don't put a gasket under the nut - if water gets between the nut and the glass, it has no path to the outside world because the only potential exit points are sealed by the two gaskets mentioned above. Water will potentially get between the shaft of the gasket and the void through which the shaft passes in the holes you made in the box or tank, but it can't get "out" anywhere so it's not a problem.

Secondly, the gasket on the nut will do nothing to prevent leaks from traveling along the threads between the nut and the bulkhead, which are "normal" straight cut threads (not pipe threads) and will likely not form a good seal (this is by design - if the nut was pipe thread, you wouldn't be able to tighten it against a tank wall of arbitrary thickness). So even if you put a gasket under the nut, water can still get in to the same void I described above, which makes the gasket moot.

Also, I'm trying to understand your point about the fitting assembly becoming too "soft." I gather that you are saying the assembly needs a hard contact somewhere so that the nut can be screwed more tightly, reducing the chance of leakage. Thus, you seem to be saying that using a third flange to reduce the risk of leakage would actually have the opposite effect.

Yes, you seem to understand my concern correctly. Even on large bulkheads that only have one gasket, if you torque them correctly, you can still sometimes accidentally cause tiny, temporary leaks thanks to the give in the soft gasket by putting too much force on the plumbing (i.e. turning a stiff valve connected to the plumbing, etc.) I was voicing concern that if you have three soft gaskets, you're going to have more "play" (assuming you don't overtorque the fitting) and hence more likleyhood that an accidental bump to the box could cause enough flex to lead to an issue.

Overall I don't honestly see this as a big problem and you'd probably be fine either way, but I did want to put it out there.

 

[SkyReef]

Gotcha. I would argue that, technically, there is no such thing as a reverse orientation - as long as there is a gasket on the flange side it's "correct" and will be leak-free. Using the bulkheads to seal two holes introduces a bit of complexity but the same logic applies. As long as the flange is gasketed to whichever surface it's touching, and there's a gasket between the box and the tank, it can not leak (assuming those gaskets are sound). Assume you don't put a gasket under the nut - if water gets between the nut and the glass, it has no path to the outside world because the only potential exit points are sealed by the two gaskets mentioned above. Water will potentially get between the shaft of the gasket and the void through which the shaft passes in the holes you made in the box or tank, but it can't get "out" anywhere so it's not a problem. Secondly, the gasket on the nut will do nothing to prevent leaks from traveling along the threads between the nut and the bulkhead, which are "normal" straight cut threads (not pipe threads) and will likely not form a good seal (this is by design - if the nut was pipe thread, you wouldn't be able to tighten it against a tank wall of arbitrary thickness). So even if you put a gasket under the nut, water can still get in to the same void I described above, which makes the gasket moot.

These are excellent points that I had not considered. I had not thought about the water that can escape a gasket on the nut side, by means of the threads. As well, it makes sense that the gasket between the wooden, external overflow-box and the rear, glass wall of the aquarium would block any water propagating along the threads, along the shaft, from inside the aquarium's internal overflow-box. So the gasket at the nut side is really superfluous and can pose additional risks with a soft-assembly setup.

Yes, you seem to understand my concern correctly. Even on large bulkheads that only have one gasket, if you torque them correctly, you can still sometimes accidentally cause tiny, temporary leaks thanks to the give in the soft gasket by putting too much force on the plumbing (i.e. turning a stiff valve connected to the plumbing, etc.) I was voicing concern that if you have three soft gaskets, you're going to have more "play" (assuming you don't overtorque the fitting) and hence more likleyhood that an accidental bump to the box could cause enough flex to lead to an issue. Overall I don't honestly see this as a big problem and you'd probably be fine either way, but I did want to put it out there.

These are also really good points. So the adverse risks posed by the use of soft-assembly outweigh any conceivable benefit. Moreover, any such conceivable benefit is not likely to occur, given that water can travel along the threads past the nut-side gasket. Thanks again, very helpful information!

 

[SkyReef]

STATUS UPDATE: Wooden, External Overflow-Box Painted (Except Bottom)

STATUS UPDATE: Wooden, External Overflow-Box Painted (Except Bottom)

STATUS UPDATE: The wooden, external overflow-box has been water-proof painted with multiple coats of epoxy paint. Only the bottom side remains to be painted, which I expect to do tomorrow. The number of coats on the panels of wood varies, based on the anticipated difference of water pressure at each panel location and exposure to risks of splashing, set forth as follows:

• Outside of Box at Interface with Back Side of Aquarium: 3 coats;
• Outside of Box at Ends and Open Side: 2 coats;
• Inside Floor of Box: 4 coats;
• Inside Walls Above the Bulkhead Holes: 3 coats; and
• Inside Walls Below the Bulkhead Holes: 4 coats.

As always, I welcome your thoughts, suggestions, and advice. Here are some pictures of today's painting:

Pictures 1-3: The Overflow Box Being Sanded Down to Receive Paint Today. Please recall that the box had already received 2 coats of epoxy paint from last weekend. Thus, today, I was adding more coats of paint, before which I had to lightly sand down the surface of the old paint, to scuff off the gloss:

Pictures 4-5: The Overflow Box with a Wet Coat of Paint--a very thick coat.

Picture 6: The Overflow Box with all coats on, except the bottom, after four hours of drying time. The inside floor of the box will still need a few days to dry, given the very thick coats applied there.

On a somewhat related task, while painting the box today, I also painted the outside, back wall of my aquarium, which will interface with the wood, external overflow-box. I applied 7 coats of Krylon Fusion, Mat Black, at 1 hour intervals, per manufacturer's recommendations. Here are some shots:

Picture 7: Rear, Exterior Wall of the 75-Gallon Aquarium Before Being Painted:

Picture 8: Same View after 7 Coats of Krylon Fusion Paint:

Picture 9: Front View, Looking Back at the Painted Glass:

 

[18fisher]

looks great but wow thats alot of work for an overflow box,any updates if it works maybe i can make a monster sump the same way 18fisher

 

[SkyReef]

looks great but wow thats alot of work for an overflow box,any updates if it works maybe i can make a monster sump the same way 18fisher

Thanks for your response, 18fisher. It's a lot of "waiting time" more than it is a lot of painstaking work. For example: waiting for the waterproof paint to arrive can take up to 5 days; waiting for the glue to dry takes a day; and waiting for each coat of paint to dry takes 4 hours with no sanding, or if done on consecutive days, with sanding. If you run out of time easily, like I do (I don't have a lot of free time, due to family and career commitments), then you have to continue the work in consecutive weekends, which is a huge time-kill.

The work of cutting the plywood panels on a table saw went quickly and was fun. Gluing and screwing the wood panels into a box was fun, once I figured out what the hell I was doing. Sanding the box and paint was no big deal. Chipping and sanding the glue goes quickly. Sanding the gloss off the paint is as easy as applying an eraser to a chalk board. I think your point is that such an expenditure of time and effort to produce a "small" result in an overflow box seems silly, whereas the payoff would be much bigger with your monster, wooden sump--or even a very large aquarium. You might be right. Yet we are constantly admonished by our fellow aquarium hobbyists not to "rush" the practice of building and maintaining a successful aquarium. So I'm good with the amount of time and effort spent here.

I know that I spent a lot of time trying to build the box out of glass, which is a most unforgiving material to work with if you make mistakes. I make mistakes. In the end, it may have taken me more time to build the overflow-box out of wood, but it was far less stressful than working with glass. I actually enjoyed working with the wood, where I did not enjoy working with glass. So the time I spent on the wooden overflow box did not seem like "work." Working with glass--including: obtaining it from glass shops; double-checking the quality of their work (by measuring distances and angles) while they stare at you defensively; haggling and returning glass panels not cut or drilled correctly; and waiting to be resupplied with correctly-drilled-and-cut glass panels--was far more stressful than obtaining, cutting, and boring holes in a single sheet of plywood. Those who build aquariums from glass are very skilled, like Uncleof6. Doing so is easy for him. Also very easy is building an internal overflow box, where you are just attaching an "L" to the back and sides of an aquarium. You can rest more easily at night with an internal overflow-box because if a small leak develops, your coast-to-coast will not skim the water properly, but you face less a risk of leakage than with a failed, external overflow-box. Building an external overflow-box bring one's exposure to adverse risks to a whole new level. It is essentially having another aquarium sitting on the back of your aquarium. Two aquariums, twice the risk of leakage, if not constructed properly.

But I get what you are saying: there is economy achieved in larger-scale projects made of wood, as compared to a smaller, overflow-box. I wish you luck on your monster sump! Thanks.

 

[NanoReefWanabe]

i would make sure you have as much epoxy as you can inside the holes of the box to tank side...those holes will always have water standing in them...as username said, the water will seep past the threads and be standing in the glass holes and wooden holes of the junction between tank and box...any pin holes in the epoxy will allow water to get in the wooden box, and then you get swelling and possibly serious issues...

 

[SkyReef]

i would make sure you have as much epoxy as you can inside the holes of the box to tank side...those holes will always have water standing in them...as username said, the water will seep past the threads and be standing in the glass holes and wooden holes of the junction between tank and box...any pin holes in the epoxy will allow water to get in the wooden box, and then you get swelling and possibly serious issues...

Thanks, NanoReefWanabe: It's a great point. I think after I get the bottom painted, I will scrutinize very carefully over the epoxy paint adhering to the cylindrical wall of the horizontal holes. I will overload those holes with as much paint as I can. The only limitation I face is making sure I leave enough space for the bulkheads to fit through.

It seems that the risk of water-seepage and wood-expansion is less pronounced in the vertical holes that accommodate drain lines and a return line because the side facing the water in the box is the flange side, not the threaded-nut side. Is that theory correct?

 

[dryworm]

hi, this is a little off topic but what is the advantage of the external overflow box over the internal bean animal setup?

 

[SkyReef]

hi, this is a little off topic but what is the advantage of the external overflow box over the internal bean animal setup?

Thanks for your question, Dryworm. The only advantage I appreciate here is one of aesthetics. By pushing the BeanAnimal-System components to a compartment behind the tank (i.e., to an external overflow box), I can eliminate the sight of those PVC components inside the tank. Moreover, by not needing to accommodate those PVC components inside the tank, I can make the internal weir (i.e., the internal overflow-box) skinnier from front to back. This is true because nothing but water need fit inside the internal overflow-box, and that water exits the rear of the tank into the hidden, external overflow-box. Thus, in the end, the tank looks cleaner and sleeker.

 

[dryworm]

ah ok, i understand now. how many inches in depth is your weir. and how far down is it. your tank looks great by the way and glad your posting pictures of it for others to see.

 

[NanoReefWanabe]

Thanks, NanoReefWanabe: It's a great point. I think after I get the bottom painted, I will scrutinize very carefully over the epoxy paint adhering to the cylindrical wall of the horizontal holes. I will overload those holes with as much paint as I can. The only limitation I face is making sure I leave enough space for the bulkheads to fit through.

It seems that the risk of water-seepage and wood-expansion is less pronounced in the vertical holes that accommodate drain lines and a return line because the side facing the water in the box is the flange side, not the threaded-nut side. Is that theory correct?

not correct, water will come from the internal box to the external box via the external threads of the bulkhead...as mentioned the rubber gaskets squished between the box and the tank and the flange and the box will prevent any water from escaping the setup, but rest assured, as you have the bulkhead positioned, the outside of the bulkhead will always be wet...in your case it matters not which way you have the bulkhead it will always be wet on the outside...the vertical holes will be of no concern as long as the flange is on the inside of the box...as water cannot pass the rubber gasket and flange...if you install the vertical bulkheads with the flange on the outside?bottom of the box then you will again run into the outside of the bulkhead being wet and the possibility of water penetrating the epoxy and wood, via the edge of the holes...in theory the bottom holes dont need any epoxy in them since there is only water on one side of them and the bulkhead can be installed so that water never gets to them...the horizontal holes however have water on both sides, and there is no way to prevent water from getting to the inner surface of the holes...i reality only the bottom half of the holes will likely get wet, as the water going through the bulkheads will likely be doing so not much higher then half the depth of the bulkheads...if the water flow is restricted enough you can keep the holes full of water though if you wanted...

if you have old bulkheads you can place them in the holes, centre them, and then fill the holes (the gap between the bulkhead and the holes with epoxy) allow it to cure, then remove the bulkheads, and give it a quick sanding to give yourself a little bit of wiggle room for the aligning the box to the tank. that should give you a nice thick layer of solid epoxy inside the holes...

be very careful to make sure the outside surface of the box remains perfectly flat, otherwise the bulkheads may have trouble seating and sealing, and torquing down the nut may put a considerable amount of stress on the bulkheads and tank...if there is a fillet of epoxy around the holes be sure to flatten it out...

personally if it were me i would simply silicone the box to the back of the tank...it could be done essentially the same way you would silicone a valve cover to an engine head, run a bead of silicone around all the holes, i would do a fairly thick 1/2" bead about 1/4" away from the holes, (if you want you can create a second bead just outside of the rings around the holes, you could even go as far as the edges of the box just to give it a little more adhesion to the tank) very carefully place the box on the tank (obviously the tank will need to be sitting on its face), gently put the bulkheads in the holes, being careful not to get too much silicone on them...simply allow the weight of the box to squeeze the silicone...(ie dont install the nuts, just use the bulkheads for alignment, hopefully you have already drawn a line on the tank that indicates level or you have built the box to sit perfectly level with the top of the tank) allow the silicone to cure a day or two, possibly longer as it is fairly thick in there...if you want you can weight the box down a bit with a couple books...(from the inside of the tank you should be able to see how thick the silicone gaskets you are making are, you want the silicone to remain about an 1/8" thick after it squeezes down..) once cured you can install the nuts and torque them down a 1/4 turn past hand tight...this will further squish the nice thick (cured) silicone gasket you have made...essentially you will fasten (silicone) the wooden box to the back of the glass tank, this will help relieve stress and weight applied to the bulkheads and glass from the weight of the full overflow box...as you mentioned wooden legs under the box should be used to further support the weight, and to remove stress on the bulkheads and tank...if the back of the tank is painted black (which it appears to be) you will need to remove the paint where the silicone is going to be (easily done with acetone), then use black silicone (any will work, RTV103 would be my choice)

 

[SkyReef]

...the vertical holes will be of no concern as long as the flange is on the inside of the box...as water cannot pass the rubber gasket and flange...

Thank you for your response, NanoReefWanabe. I think we are saying the same thing. In the horizontal-bulkhead setup, the horizontal holes will always present standing-water issues because, no matter how you position the bulkhead in the horizontal arrangement, one end will always submerge bulkhead threads in water--either in the internal overflow box or the external overflow box. And where one has bulkhead threads in water, that water will travel in the grooves of the thread, past the bulkhead nut, but not past the gasket/seal. Hence, standing water is trapped in the cylindrical hole on the outside of the bulkhead stem. That is why the epoxy there must be solid, with not even the tiniest of pinhole-sized holes. You and UserNameInUse have done a good job of educating me on that issue. Thank you.

My question actually concerned the vertical-bulkhead setup. The vertical bulkhead does not present any threads to water, as they are exposed only to air, beneath the box. This is true because I would not have the threads of the vertically-oriented bulkheads positioned inside the external, overflow-box. The bulkhead would be positioned such that the flange of the bulkhead would be on the inside of the box, while the bulkhead threads would be positioned only outside the box. I was asking, in my last post, whether this theory is correct. If I understand you correctly, we are in agreement on this point.

in reality only the bottom half of the [horizontal] holes will likely get wet, as the water going through the bulkheads will likely be doing so not much higher then half the depth of the bulkheads...if the water flow is restricted enough you can keep the holes full of water though if you wanted...

Great observation. I will pay extra attention to that location. Thank you. Appreciate it.