DIY 60 gallon stand - Do I need a center brace?

[eugreef]

http://www.sdreefs.com/forums/imagehosting/63404b523c9979d6d.bmp

Does this stand need a center brace?

The top brace is 2X6, everything else is 2X3.

Ive read that the maximum deflection that silicon, in a tank, can take is 1/8" before it starts to fall apart. I think it is reasonable to assume that the best case scenario is zero deflection. The total weight of the tank, water, live rock, canopy, lights + for my setup is about 700 lbs. Since there are two horizontal beams each beam will support 700/2 = 350 lbs loaded uniformly. For calculations lets assume its uniform loading.

deflection for:
(2X4) Horizontal top struts - .038"
(2X6) Horizontal top struts - .01"

I see a lot of stands on reefcentral that have no center brace with longer spans between the vertical end struts. If failure occurs at 1/8" deflection (2x4)'s provide a 3x factor of safety while (2x6) provide a 12x FOS. I dont think at all its over engineering to use (2x6)'s. I feel uneasy that the horizontal members will constantly be deflected due to the weight of the tank. With constant deflection the silicone seams will also be in a constantly loaded/unnatural state. This may not be too bad, because the enormous pressure of water will load the silicon seams. But too much is no good. My question is not how much is too much, but is designing a stand knowing that it will deflect smart? I would really like to not have a center brace so I can have a deeper sump/refugium. Any input??

[nahtanoj]

you don't need a center brace. if you really want to feel safe go with 2x6's. a plywood top will also help spread the weight of the tank and minimize any deflection.
i have a 60g stand in my garage with no center brace, and basically is supported with plywood. you will have no problems.

[tom619]

i have the same EXACT design for my standard 60 and no, it does not need a center brace, though it would help. i had the same dilemma too: trying to maximize the sump.
my suggestion is to sit that skeleton stand apart from the wall, but make the skin deeper to cover the space between the stand and the wall. that way, you can scoot the sump all the way in.

i would have a front center brace b/c it would help to split the doors too if you're planning to make doors.

whenever you make a diy stand, dont forget where the drilled hole is coming down. i almost covered it b/c i didnt pay attention.

[eugreef]

http://www.sdreefs.com/forums/imagehosting/63404b52943f03354.bmp

Thanks for the input guys. This is the stand with the 1/2" skin. The front panel will have a built in center brace but the back will be open. The front panel will help minimize deflection in the front but now im worried about off balance deflection from front to back, since the back have no skin.

[tom619]

yup thats exactly how i would do it.

[tom619]

if you're not gonna have a center brace in the back, may i suggest this?:
just another ledge under the original one for support. ..it will be out of your sump's way. I'm just afraid it would curve over time.
that's how i would do it differently, given another chance.

tip: all my skin pieces are magnetic click-on. that way, i can pull them off should i need to reconfigure the wiring or anything out of reach.


http://i730.photobucket.com/albums/ww308/Tom619/63404b523c9979d6dx.jpg

[ManTis]

No, u dont need a center brace. Here is a stand that I made but it is only 32 inches high.

http://i244.photobucket.com/albums/gg34/m-nguyen/equipments/IMG_7049.jpg
http://i244.photobucket.com/albums/gg34/m-nguyen/equipments/IMG_7050.jpg
http://i244.photobucket.com/albums/gg34/m-nguyen/equipments/IMG_7051.jpg
http://i244.photobucket.com/albums/gg34/m-nguyen/equipments/IMG_7052.jpg

[Bio-Nut]

No center brace is needed the runners ran as a strong back (as you have them designed) is safice for holding a lot more wait than that! And firmly attaching the ply skin you will give it plenty of shear stength. Just try to use a sold piece on the front so that you can aquire the stability you need from this!

Need any help or a way to get material cheep! let me know!

[nahtanoj]

http://i95.photobucket.com/albums/l127/francis1123/IMG_9468.jpg

even more proof, that is a 115g with no center bracing on the stand.

[eugreef]

Thanks for all the great input! This is only my second DIY stand so all your guys experience will really help.

Is there any way I can attach the vertical struts to the top horizontal brace without using nailers?

Also, Does anyone know of a place where I can pay a flat day rate and use woodworking tools? Im gonna need a table saw, jig saw and other woodworking tools.

[Fishlvr619]

I have all the tools you need and are looking to borrow and if you want you can come over one weekend and I can help you build it and you can use my table saw compound miter router or whatever you need.I just built my frame for my 120 and I going to finish the skinning tomorrow.I also am going to put molding and columns on the corners.Kinda like Tanner's Stand.Just let me know. I enjoy working with wood and would like to help another reefer build his own stand.I think it is a great accomplishment to build your own stuff.My name is Beau and my # is 619-504-3808..Good luck

[SoCalBoo]

I have a 120 (4x2x2) with no center front brace, and it has no visible deflection. I did put a center brace at rear, though. It is all 2x4. I ended up putting a 2x3 in the middle front so the doors had something to close against, but it has 2 screws on top and bottom to remove if necessary (such as changing out the sump). I purposefully cut it about 1/16" short to see if there would be any load on it, and there isn't.

If you are nervous, you could do 2x6s, but it isn't necessary. 2x4s should be more than enough. It has been about 20 years since my structural engineering classes at UCSD, but I recall 2x4s laid on their sides can handle a serious load, especially with thick plywood on top disbursing. I dare say your are barely taxing them... Keep in mind that there are thousands of homes in San Diego with 2x8s, 16oc, that make up the floor supports on 2nd and 3rd stories, spanning lengths over 15 feet, with no appreciable give.

Whomever said magnetic sides - that is genius. Gonna have to borrow that one soon.

[johnc]

You will be fine, the weight will go to the legs and straight down

[eugreef]

I have all the tools you need and are looking to borrow and if you want you can come over one weekend and I can help you build it and you can use my table saw compound miter router or whatever you need.I just built my frame for my 120 and I going to finish the skinning tomorrow.I also am going to put molding and columns on the corners.Kinda like Tanner's Stand.Just let me know. I enjoy working with wood and would like to help another reefer build his own stand.I think it is a great accomplishment to build your own stuff.My name is Beau and my # is 619-504-3808..Good luck

Hey Beau. Thank you I really appreciate the offer. I am still getting the complete design figured out (moulding and all). I might take you up on your offer!

[Fishlvr619]

Hey you are welcome.I just finished my stand and it looks pretty decent.I also forgot to mention that my tank is a 120 and I have no center brace either. I just used (2) 2 X 4's doubled up like a header for a weight bearing load.Screw them together and you have more than enough strength.I will post a picture tommorrow if you would like.Or I can email it to you.I also have 3 cross pieces for the bottom of the tank including one cross piece on each end.good luck..

[eugreef]

Hey you are welcome.I just finished my stand and it looks pretty decent.I also forgot to mention that my tank is a 120 and I have no center brace either. I just used (2) 2 X 4's doubled up like a header for a weight bearing load.Screw them together and you have more than enough strength.I will post a picture tommorrow if you would like.Or I can email it to you.I also have 3 cross pieces for the bottom of the tank including one cross piece on each end.good luck..

So you just doubled up the across 2x4's side by side? Or did you put one 2x4 on top of the other? A picture would be great!

I am starting to think that 2x6's for the horizontal top struts are overkill.

[eugreef]

even more proof, that is a 115g with no center bracing on the stand.

Hey, what do you have as a top bracing for your frame? 2x4's or 2x6's?

[Fishlvr619]

I have the (2)2 X 4 's doubled up so if you are looking directly at the front of the stand the widest part of the 2X4 is facing you.

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Hope this helps...