# Making a 180 Gallon stand advice



## skrick

hello everyone Im making my 180 gallon stand out of 3/4 maple plywood with 2 doors on either end and open in the middle all spacing between support dividers that run front to back are about 18" so there are 5 total supports of 24X33 high and all piece's of 3/4 inch plywood along the back. Personally I think it will be fine, but it is still alot of weight what do you guys think Im going to dress it up a bit here is my list of pieces.

2x tops and bottom 73x25
1x back pannel 72x33
supports x5 24x33
2 doors 18x32 3/4 

all screwed and glued together I just want simple with some shelves all is #1 grade maple plywood 
Sooooo........... do you guys think it will be fine I built my 90G stand like this and it turned out bulletproof some advice would be nice Thanks Bobby


----------



## target

For my stands I always like to have a 2x4 frame supporting the tank. The plywood becomes just the outside cover, not really for support. I just like the peace of mind it gives. You are about to put 2000 lbs worth of tank and water on top of 3/4" ply. For $10 worth of 2x4's, it's worth it in my opinion. Plus, making an internal frame would allow you bigger openings for access to under the stand. Just my 2 cents though.


----------



## skrick

I guess your right 2000lb vs a 90G is a big difference to build a frame 1st and then skin it better for protection I was just looking at my buddy's tank and its a 210G bowfront and its on pine from the store no big wood frame just looked shabby so Thats why I asked


----------



## taureandragon76

Ya most store bought stands don't have any framing inside but as Target said I would feel better having it framed then skinned


----------



## skrick

Done I will do the framed thing as I was a framer in my day too and woodworker so tools I have so I guess ill use them just being lazy also I just didnt want to add to the weight


----------



## skrick

Id like to add this is going on my 2nd floor also I looked at the joist situation looks to be ok rough cut 2x10 on a wall made of 2x6 framing on the exterior and the joist only span about 14' till the next wall tank is up against the wall


----------



## Jonney_boy

Either way will work as long as your floor holds 

Building a 2x4 frame is easier and cheaper, in fact you can step down to 1/2" or 5/8" ply with no problems as the tank is supported.

Having said that, there are times I "want" to maxmize the space and will build the stand completely out of ply, if that is the case make sure you have enough supports (in your case 5 supports), double up the top, and the back is "inserted" into the cabinet. This will ensure the cabinet does not get out of square. .. no thin hardboard for a backing here, use the same 3/4" stuff .

You also want to ensure that the side pieces are inbetween the top and the bottom, helps allow for better weight transfer.


----------



## gklaw

skrick said:


> Id like to add this is going on my 2nd floor also I looked at the joist situation looks to be ok rough cut 2x10 on a wall made of 2x6 framing on the exterior and the joist only span about 14' till the next wall tank is up against the wall


2x10 spanning 14' is a long way!

My 2x10 floor only spans 12.5ft - I think at 16" oc. It is bouncy. I have a 75g sitting one edge on a bearing wall. The floor does give.

I think you are probably fine with 1" plywood for the dividers - its the same price as Maple but stronger. Finish off with Maple doors and end gables ?


----------



## skrick

I know my floor does scares me but I just measured span is only 12.5ft to the next wall I could double up 2x10 my 110 is there now 48x18x31 and that sits up where this one would be along the exterior wall this one is spanned along a further distance of 6ft ill fill slowly and hope for the best I think ill do the plywood thing instead of 2x4 Ill build like my other stand with full sheet bracing along the front cant and cutout my doors cant go wrong aslo so it has the support like the back


----------



## pistolpete

If you're worried about a plywood only stand, consider this: the crush strength of birch plywood is around 300 lbs/square inch. That means that each linear inch of plywood can carry well over 200 lbs. So if you say that only the end walls of the stand are load bearing and your stand is 20 inches wide, then you have 4000lbs of load capacity in the end walls alone. Add to that front and back and perhaps a center support, and you end up with something like a 10x safety factor on a 180 gallon tank. With 3/4 inch material the slenderness ratio comes into play, but that is negated by the box shape of the 
stand. 

doubling up the top plate is absolute nonsense from a physics perspective, as it does nothing to improve load capacity, but making the back of the stand solid does help a lot. Stands framed with lumber are simply an easier way of doing things for people with limited woodworking skills.


----------



## target

Lol, limited woodworking skills because you add a support frame? That I don't agree with. Why would it take less skill to add a support frame? Yeah, you can be fine with just the plywood, same as a store bought stand is good enough. But when building custom, why not overbuild a little, especially since it's going on an upper floor with a longer span? A 2x4 frame would be less prone to flexing if the floor moves slightly.


----------



## skrick

Yeah charles also gave me SH^t too Ill build it with 2x4 then sheet it it is more work to finish the inside though and hide the 2x4's outside sheeting is easy but yeah I dont need any problems in the long run


----------



## bingerz

skrick, take a whole mess load of pictures!! i'd like to see a journal build!! good luck!!!! *thumbs up!* wish there was a thumbs up emoticon.


----------



## skrick

haha no problem Ill do so


----------



## Clownloachlover

for what it is worth, I built a 2X4 stand in a matter of a couple of hours and it took about 30 bucks in 2X4's to do it. Simple & cheap and the crush strength of 2X4's far exceeds the weight you will place on it with 180 gallon tank. I have a 230G tank on mine and I am confident it will support the tank with no issues whatsoever, however I have it sitting on a concrete basement floor.


----------



## tony1928

For DIY, I would definitely do the 2x4 method. I know most prefabbed stands out there are plywood or even just particle board or hopefully at least MDF. But there's some nice engineering going on there to build it so it can support the load. So technically there's no problem doing it just with ply, but for peace of mind, use the lumber. That being said, when I finished framing my stand, it was so bloody heavy. I could barely move it. I would bet that the stand weighed close to 200lbs alone. Also, the 2x4 stand is so stable if built properly.....no swaying possible. Makes it alot safer.


----------



## taureandragon76

I built my stand for my 135g which is 6' long and 2' across outta 2x3's and have 3/4" plywood on the top and back. I am more than confident it will hold.


----------



## pistolpete

did I ever open a can of worms did anyone actually think about the math in my post? A 6 foot by 18inch stand with one center support, all made out of 3/4 ply will support 25200 pounds. That's right, twenty five thousand. Of course that's in a completely static situation, but you can't argue with the math. So my point is: if a plywood only stand carries 25000 pounds, what the heck is the point of adding the extra weight and making it support 35000. 

i did not say adding 2x4's is wrong, but it's completely unnecessary. Aside from the weight issues, dimensional lumber is never all that dry and shrinks about 1/8" over time. This stresses the plywood skin attached to it and makes the stand warp slightly. 

I'm not just spouting theory here. I have built somewhere between twenty and thirty stands with and without dimensional lumber. I also happen to be a carpenter, though I've been setting tile for the last few years.


----------



## gklaw

Almost think Pistolpete is an engineer. I am. I have to say that I have to agree with Pistolpete. I tends to play it a safer. 3/4" plywood support every 18" will be more than plenty. Other factors that comes into play is the stability of the stand.

Having said that, if it makes someone feel and sleep better by using 2x4 - why not. 

I use oak plywood because I found it easier to assemble with screws and therefore easier to dissemble to modify for the future. When I finish, stain and varnish, I have a piece of furniture  For my 6ft plus breeding stations. I removed a dozen of screws, took out two middle supports, added a strip of plywood for support and crated the space I need for a 36" sump.

I have build a triple stacker with 1" plywood for my SW tanks. The painted MDF I used for the flat surface under the tanks did not fair too well. Still rock solid after almost 10 years.


----------



## Aquaman

Go with a steel stand and cover with 1/8 veneer , plywood You would have lightweight more inner space and removable panels. Much lighter than a wood stand, tho that would require a welder.
I have made several wooden stands and a couple of steel and. If I ever make another it would be steel / plywood.
I ain't no egineer, or anything but if that piece of plyvwood 4 feet tall and 8 feet long can hold say 5 ton how much wood ( pun intended ) it support if it were 8 feet long and 20 feet tall ? Just curious  I know a 2 x4 6 inches long stood on end will hold more than a 8 footer standing on end.
Just one of many thoughts rattling around in my head while reading this thread from my iPhone


----------



## pistolpete

What you are talking about is the slenderness ratio. With wood that ratio is approximately 20 to 1 (depends a lot on species, core voids, knots, etc.). This means that when you exceed 20 times the thickness of the material it will buckle and break rather than fail in compression. This means that a piece of 3/4 inch plywood stood on end and tested to destruction will buckle if it exceeds 15 inches in height. Fortunately for stand builders, having the corners tied together stabilizes the sheets and the slenderness issues are almost completely eliminated. 

You can easily demonstrate this with cardboard. Take a piece say six inches by six inches. Stand it on edge and apply pressure down. It will buckle relatively easily. Now fold that piece into a 4 sided column and put some tape around it. it will take considerable force to make it fail.


----------

