DIY Stands Template and Calculator

[110galreef]

The whole point of using 2x8's instead of 2x6's for the horizontal pieces is so that you won't need an additional vertical "center support", but it can't hurt, and it will reduce the <1/8" deflection to almost zero. But don't buy any extra wood for it (like a 2x6) just use a piece of 2x4 or whatever you have laying around.

Using two 2x8's on one side is unnecessary, and complicates the design, a single 2x8 is more than sufficient.
I wouldn't go thinner than 3/4" plywood


If you must double up the 2x8's, I like the design on the right better. The design on the left is making a 2x4 do double duty, as both a leg, and as a screw strip. If the two legs aren't exactly the same length, or the floor under them isn't exactly flat, then there will be sheer stress on the screws. If you use pocket screws you don't need a screw strip, but a screw strip is better because it provides some protection against wracking (folding) that pocket screws do not. If you use pocket screws, you'll need to skin the sides, or at least use triangles in all the corners (I'd do that even if I used screw strips). I suspect that sheet rock (dry wall?) is a sufficient skin. Even a medium sized earthquake can move a couple inches side to side, and without more support those corners could fold with that much weight on top trying to NOT move side to side.

There will only be about 15" between them, so yes, more than good enough. 2x6's would also be more than enough.

For sure you can substitute 2x6's for 2x8's everywhere except maybe for the double's along the back. While a single 2x8 would be fine there, two 2x6's probably wouldn't be. The cross members will be hanging on only the inside one of the pair, so it will be taking much more than half of the load for the pair. Also, even a very slight bowing of the "flat" top will cause the plywood to push down along the inside edge of the inside 2x6, and push down very lightly, if at all, on the outside one. Using two instead of one is a fundamentally different design, and so is unstudied and untested. The inside 2x6 would be holding most, if not all, of the weight for the pair, and we know a single 2x6 wouldn't be enough. Using a single 2x8, on the other hand, we know for sure will work.
Sure, no problem. As long as the end of every horizontal piece has at least part of a vertical leg under it, you'll have no problem.

Thanks, I think what your saying in short is, If I simply keep the picture as is, just not double the back support and keep the framing 2x8's and then use 3/4 plywood top. This work work fine, legs, frame, crossbraces and all....RIGHT??:hmm5:

 

[110galreef]

110 as C-Rad pointer out with the current design the cross braces are held by the 6 foot run. On second thought I thought this as a bad idea. So rather than have 3 vertical (in your picture) support 36 iches (or so) long. Use two that are 6 geet (or so) long. Have 4 legs on the ends so each one is supported.

As mentioned many times a horizontal run should have support at each end. It was not till I saw the picture and thought acrylic that I ut it all together in my head.

I hope this helps.

I thought about running the 2 horizontal cross braces(66" span) as oppossed to the vertical ones (36" span) as well. However, I want full access from the sides as well, but probably not necassary. So the supporting legs on the side for the cross braces may be in the way. I can relook over my design and see for sure.

If i went this route would all 2x6 work for the frame then? Since i now would have 3-4 horizontal cross braces that would be 2x6 all supported to the ground on the edge. That would make 3-4 -2x6 spaced about 12" or 18" apart sharing the load of about 2000# (8# x 250gal). Then simply put a cross brace or two to keep all this from twisting. First post stats a 2x6 frame up to 72" will support 125-150g tank. So I basically would have two 125g stand sandwiched together.
I think I prefer my original drawing if that works just fine?

 

[TheFishMan65]

I don't like the unsupported cross brace. Maybe someone else will chime in.

 

[110galreef]

anyone w/ info on the cross braces for acrylic tanks? Just screws to hold them? I read a ton of these pages & seeems all I find are glass tanks so the cross brace is just to keep the frame from twisting so no load really on it? I know my last tank that I bought was acrylic & stand made for it the cross braces were just screwed in to sides.

 

[110galreef]

I have considered, the hangers & screw or making cross braces 2x4's & run a 2x4 along the horizontal 2x8's for the cross braces to sit on. But not sure if the 2x4's would be strong enuf. So fo now, the hangers & screws should work. I really don't see any more than about 500# on a cross support at any given time. The hangers & screws should be fine supporting that. If the 2x4 for cross braces are enuf that i like as well supported w/ another 2x4

 

[TheFishMan65]

Hanger are probably fine, desks hold more than 500 lbs. I just don't like metal and saltwter together - you might consider painting them, but I don't think that is the whole answer. I just thought if you could do it the longe cross brace might be safer.

 

[110galreef]

Hanger are probably fine, desks hold more than 500 lbs. I just don't like metal and saltwter together - you might consider painting them, but I don't think that is the whole answer. I just thought if you could do it the longe cross brace might be safer.

I believe they are all galvanized. i can always shoot them w/ rustoleum. I am sure that will also help. They should be pretty far from any salt. also I will run SS screws into the cross braces from the frame as well. between that sounds like I will be good.

Also should I go w/ 1/4 styrofaom under tank? plenty to pick up imperfections?
Thanks again for all your help!

 

[Northern Sensei]

ok i think i have a pretty good idea about how i am going to build my
stand for my 220g tank.
I do have one question

if i made it out of 4x4 would i need a centre support which would stand
vertically in the middle to support the above horizontal 4x4? i mean is a 4x4 strong enough to make the span of 72 inches wide. So this means that i wold
have only vertical supports underneath ALL 4 corners correct!

thanks for the wicked thread and to everyone who has added info to this.....

 

[RocketEngineer]

Northern Sensei,

The problem with a 4X4 is that the center wood reacts differently than the outside wood due to their size. In addition, they are typically cut from the center of the tree which is now released from the compression it had been under now that the tree is cut down. These factors cause them to twist, warp, and/or split over time. A 2X4 is more dimensionally stable. Given that the verticals are so short, a pair of 2X4s is just as strong and much less likely to cause problems.

Based on my numbers, for a 6' long 220g tank, you need a 2X8 top frame to support the tank with less than a 1/8" drop in the middle. This is what I consider safe but there are many different ways of evaluating what is the appropriate amouunt of support for a glass tank.

RocketEngineer

 

[Northern Sensei]

RocketEngineer

so could i double up on the 2x8's to prevent the 1/8 inch drop?
Or could i place some 1/2 plywood to cover the whole top? or both?

thanks so much for the help RocketEngineer

 

[trmiv]

Great thread. I'm going to use this design to build a stand for my 60g marineland cube which is 24x24x24. The stand I want to build will be 24x24x36, so it will be a foot taller than it is wide. Because of the limited space inside, I want to make it so the "skin" is actually removable. It will have a door, but when needed I'd like to be able to just take the entire front and sides off to be able to remove the sump, etc. Is this a viable idea, or will there be too much twisting and racking without a permanent skin on the frame of the stand?

 

[TheFishMan65]

From what I read the skin is not required and that is the way i built my stand for a 75 when I redid the stand. So far no problem (about 2 months).

My plan is to have panel that are held on with magnets.

 

[110galreef]

are the screw strips to be screwed or glued to the top frame? Also what about the top sheet of plywood....glueing or screwing or just sitting on top?

Thanks

 

[TheFishMan65]

Screw strips touch neither floor or top frame - thay are not planned to load bearing. Glue and/or screw probably. I would probably do both.

 

[Northern Sensei]

with regards to "screwing or glueing"

If it were me doing it i would just glue the top sheet of plywood, if you use a product like NO NAILS, then it'll hold without a doubt. That stuff is very strong!

Doing both would just be overkill, and IMO not necessary.

Best of luck!

 

[TheFishMan65]

I agree, but I how well des liquid nails level? It will be really hard to calmp down the center and the las thing you want ithe center to be sticking up becuase it did not get clamped well. Never tried it so I don't know if it would be a problem. So I will just throw it out there for thought.

 

[110galreef]

Ok, rocketengineer or anyone else confirm that this sounds about right? I got the stand all done:

--Top frame, 66Lx 36w....all made with 2x8's. I put 4 2x6 (every ~16.5 center) cross braces, mounted w/ hangers & ss screws. (acrylic tank)..Topped w/ 3/4" plywood.
--Legs are 2x6 on the front & back & then 2x4's for the sides. 2x4 screw strips. So the front & back span of 66" is only unsupported for 55" total. 250g tank filled w/ about 230gals of water volume. Tank & all about 2200# ....acrylic tank & water.

TESTING FOR DEFLECTION:
I put a loose cross brace in center frame(66" run) that was about 1/8 too short and shimmed to make a snug fit when empty. Then removed it. Then filled tank full w/ water and measured the shims that would not fit back under frame in center. It came out to about .045" ie just under 1/20 deflection! (dial calipers) Does this sound right??

That sounds like very little deflection. good but Right?
I will leave full overnight to check for leaks as well and se how it is in the morning
Thanks,

 

[RocketEngineer]

110galreef, Based on those dimensions the stand is overbuilt but otherwise that sounds like you are ready to go forward.

RocketEngineer

 

[110galreef]

110galreef, Based on those dimensions the stand is overbuilt but otherwise that sounds like you are ready to go forward.

RocketEngineer

Great thanks....just seems to good to be true! These things make me woory at night. I should be good then:bounce3:

 

[lewisjl481]

I recently bought a 36"x24"x24" 90 gallon tank and am in the planning process for a stand. The sump I want to use is 28.5"x28.5" so the stand needs to be 36"x31" to fit the sump in between the 2x4s on the bottom. I have attached a picture of a Google Sketchup and would appreciate some feedback on the design. My plan is to attach 3/4" plywood to the top and bottom. The tank is rimless and made from 1/2" Starfire glass. I do not a plan to permanently attach the "skin" to the frame of the stand. Thanks in advance.