2x4's or 2x6's ???

[phunkie99]

I am building a stand for a 120 gal glass tank should I use 2x6's or will 2x4's be fine??

[james3370]

from the DIY Stands Thread......
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1567110

<a href=showthread.php?s=&postid=14306804#post14306804 target=_blank>Originally posted</a> by RocketEngineer

(2) Red - Upper Rails: Length = W
These will be sized according to length: 2X4 for 48" or less for smaller tanks (Rule of thumb is 75g-90g); 2X6 up to 72" with 125g-150g being acceptable; For longer spans and larger tanks 2X8s are recommended.

so depending on the tank length, i'd say 2x6....but if you wanted to do it w/out a center support leg in the front for more sump area access, i'd jump up to a 2x8 or even 2x10 for slight OPOM (overbuilt piece of mind) LOL

[TAB]

2x6 are over built for 2' span.

[tank o tang]

I used 2x4's for my 180 and 156 and all is well.

[coralnut99]

2X6 for my 125's with no center support. Up and running 5 years now.

[JDL]

i used 2x6's

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1597637

[Imzadi]

I think 2x4 are plenty. I don't think the demension of the lumber is as important as the trueness of it. I would be willion to bet that 2x3 would probably work... in NO way am I suggesting it, but... yea.

It's all about distribution of the load, and stability, and the ability to stay straight and true. When the wood twists... and it WILL twist, there is no way to stop it... you have to make sure that something counters it, cuz glass don't twist. The too most important words in almost all forms of construction... Glue and Screw. If you build a level and true top platform from 2x4s, and put a couple joists across it, glue and screw, then four corner posts down. Plywood sheating on three sides, glued and screwed... you shouldn't need anything in the front at all.

Surely there is a hundred examples in this DIY area of dimensional lumber bases... I love this place! lol

[Imzadi]

I spoke too soon... there is one now! That is a wicked little build, JDL!

[hllywd]

<a href=showthread.php?s=&postid=14626828#post14626828 target=_blank>Originally posted</a> by phunkie99
I am building a stand for a 120 gal glass tank should I use 2x6's or will 2x4's be fine??

This is like a helmet debate on a motorcycle forum...:eek1: My stand has neither 2x4s nor 2x6s...

http://reefcentral.com/forums/showthread.php?threadid=1163749&highlight=the+120

You can see from the pics it started life as an AGA stand made of 1Xs. When I get around to building the wall unit for where it sits, I will use 3/4" plywood. So long as the load sits directly over the 1X lumber, or plywood that is transmitting the load directly to the floor, I believe it is at least as strong as building a frame of 2Xs. The benefit is no frame inside the stand taking up space.

Tim

[Imzadi]

<a href=showthread.php?s=&postid=14628615#post14628615 target=_blank>Originally posted</a> by hllywd
This is like a helmet debate on a motorcycle forum...:eek1: My stand has neither 2x4s nor 2x6s...

http://reefcentral.com/forums/showthread.php?threadid=1163749&highlight=the+120

You can see from the pics it started life as an AGA stand made of 1Xs. When I get around to building the wall unit for where it sits, I will use 3/4" plywood. So long as the load sits directly over the 1X lumber, or plywood that is transmitting the load directly to the floor, I believe it is at least as strong as building a frame of 2Xs. The benefit is no frame inside the stand taking up space.

Tim Its a DIY 'debate' in a DIY section of a Marine Aquarium forum.... The 'Helmet' is answering the question of A or B with option C. lol But thank you for re-enforcing what my statement was. "It's all about distribution of the load, and stability"

By the by, Your tank is a pretty nice set-up.

[hllywd]

Thanks for the compliment! Those pics are a few months old and the tank is doing very well!
What I meant by my comparison is that everybody will weigh in with an opinion. In either case some will passionately defend their's to the end :D On the stand subject I've built both, and I am a firm believer in not wasting material when the lighter method seems to have a great amount of safety built in. If somebody wants to use 2x12s I would speak up and say it's completely unecessary and offer and alternative.

Tim

[Imzadi]

True that.

[Whacked]

2X6 is stupid overkill
even 2x4 is a bit much.

120g so thats what 4' long?
subtract 3.5" from the ends for the x4 studs at the corners and thats 41" unsuspended. I'd imagine you'll want double doors in the front so subtract another 3.5" and thats 18.75" per opening.

So, using 1600lbs (way over guessimate for a 120g stocked tank weight) and the 18.75" span, and using 1x4 pine, you would get less than 0.004" sag over that span. that is twice as thick as a strand of hair.

Id do like Hllywd said and build it from 3/4" plywood

[phunkie99]

I think I'll go with the 2x4's and "glue and screw" thanks for everyones input

[therealfatman]

The compressive strength of common pine is 6,800 psi parallel to the grain (upright board). Commercial stands are grossly over built so as to avoid product liability lawsuits. A common design for a four foot long all glass tank is to support it only by its two ends and to support it the full width of the two ends. Some commercial stands give the appearance of providing full perimeter support but use lumber so light running from side to side as to really be negligible. Often the side supports sit up higher than the side to side lumber so the side to side supports can not provide support.

The chief thing that needs to be considered when building a stand is to keep all the supports securly upright and to prevent racking. In bridges they use diagonal bracing. In new homes they use plywood for diagonal bracing. Stands are typically diagonally braced on the sides because they are made with panels and they are braced by the 5" to 6" upright panels (or wider in the rear). They also use glue. Nails and screws with lumber and no glue or diagonal bracing is inadequate. Remember that the weight bearing potential of the lumber is really not the prime issue in building a stand but instead the joints and the bracing are the primary raes of design concern.

When it comes to strength alone a 1 inch square piece of common pine lumber can bear the entire weight of at least three tanks of 120 gallons with rock, sand and water. Not that that would be a wise way to even hold a single tank. I always recommend DAP WELDWOOD Resorcinol used heavily on every joint. Ant squeeze out wipes off easily when wet. Put the glue on both surfaces. It is waterproof and makes a 2" x 4" stand even witout a cover skin pretty close to bullet proof.

I use 3/4" plywood for stands for 150 and 210 all glass tanks. I do not use any lumber larger than oak 3/4" by 3.5 " lumber for the side to side connection and attach a 3/4" by 3" common lumber board inside that for perimeter support of the front and rear tank. I use no inner frame of lumber for the sides, front or back (ie. corners). I use two 3/4" oak uprights between the front doors for the uprights.

I cover the entire back with a solid plywood panel then cut out holes as needed for plumbing etc. My 120 gallon and smaller tanks stands are supported only by their ends and there is no upright in the center of the tanks front or rear. I do use a four sided frame of 3/4" by three inch lumber inside the cabinet to hold the tanks bottom shelf. The front is oak to match the plywood and c other visible lumber. I buy premade kitchen cabinet doors for the front.

Or I just get lazy and buy the same thing pretty much taht is premade from PETCO. It cost about two thirds as much to make and has better lumber that the ones from PETCO which are Plywood covered particle board rather than plywood.

[TAB]

Standard wood glue is stronger then the wood itself.( when applyed correctly)

[fatcat777]

no need to go more than 2x4s, if your build your stand correctly you'll be fine.

[Whacked]

I agree with therealfatman altho houses, bridges, etc are succeptable to more & different kinds of loads than a fishtank stand.

If a stand is built correctly. Square, clean, flush cuts, use of wood glue and screws, you wont need any cross bracing since most stands have a width of 18" to 24" and are around 30"H. Also because many stands are sheathed in plywood so no x-bracing needed.

I built a stand for my 30g using nothing but 1x4. its bulletproof. If the stand is subject to any stresses that will cause it to buckle because of no x-bracing, I'll have other more pressing problems, like California has now slid under the ocean and hit with a cat-5 hurricane and tornado. the stand for my 40B will be built the same way (38"Lx 22"Wx36"H, odd size I know but there is a reason for my madness) and again, not too worried about lack of bracing.

[therealfatman]

<a href=showthread.php?s=&postid=14638571#post14638571 target=_blank>Originally posted</a> by Whacked
I agree with therealfatman altho houses, bridges, etc are succeptable to more & different kinds of loads than a fishtank stand.

If a stand is built correctly. Square, clean, flush cuts, use of wood glue and screws, you wont need any cross bracing since most stands have a width of 18" to 24" and are around 30"H. Also because many stands are sheathed in plywood so no x-bracing needed.

I built a stand for my 30g using nothing but 1x4. its bulletproof. If the stand is subject to any stresses that will cause it to buckle because of no x-bracing, I'll have other more pressing problems, like California has now slid under the ocean and hit with a cat-5 hurricane and tornado. the stand for my 40B will be built the same way (38"Lx 22"Wx36"H, odd size I know but there is a reason for my madness) and again, not too worried about lack of bracing.

I merely mentioned diagonal bracing in bridges being done by diagonal members. plywood sheating provides diagonal bracing and is the typical manner of supplying diagonal bracing with most wod framed housing and cabinets etc. A tank sitting on a stand thirty or 36 inches above the floor can easily sway and collapse without very good joint construction or bracing as through gussets or a plywood skin etc. Any tanks that are in an area where someone might fall against them or where children will play around them or where there is a chance of strong erath movement ie: earth quakes should be considered quite susceptible to stand collpse due to racking.

I do not just suggest boards being installed diagonally as being the only means of supplying diagonal bracing. I suggested plywood and/or securely screwed and glued joints as a typical acceptable standard of care. Perhaps my writing style is too convoluted to be plainly understandable.

I do strongly suggest Resorcinol Waterproof Glue not common wood glue.

[amstar]

so your saying that 2x6's I can go without center braces for a 150 gallon 6 foot long tank?

[myaerica]

I used 2x4 on my 180 with legs coming down every 2 feet never had A problem. But with the price of lumber right now 2x4 2x6 not much diffrent in price. mite as well go with 2x6 your looking at 10 $ more at the most.

[therealfatman]

I would recommend that an upright be installed in the center or 1/3 of the way out from center on both sides of center in both the front and rear, but I would not consider it a necessity, just an added assurance of safety. Most common construction (framing lumber) is not full strength structural grade lumber and is full of natural defects, most can not even be readily seen. Simple lumber matching your skin or trim would suffice as those uprights. They could even be removable to allow for installation and removal of large sumps etc.

The rigidness of all your joints in the construction is of more importance in general than a boat load of unnecessary vertical up rights. Think regidity!!!!!! Look at light weight welded metal frames. They really have no more strength than the typical wooden frame as the cross section of the metal framing is so small, they just have rigidity as they have welded (fixed/rigid) joints and just screws and nails do not supply much in the way of rigidity in comparison to welded steel. Glue provides rigidity with wood framing.