DIY Stands Template and Calculator

[TheFishMan65]

flamron, If you use 2x4 or 2x6 according to the OP you will need a center brace. It is unclear if you use 2x8 if you will need them, sorry I am not a structural engineer. If you use 2x4s or 2x6s one brace in the center (and of course the ends) is enough.

 

[RocketEngineer]

So I have a tank that is 96"x36"x12"

Total volume is 160-170 gallons.

Could I build a stand out of 2x6's for this tank? What about 2x4? I'd really prefer to not have any bracing in the middle at all, as I want that area open for equipment.

Running the numbers, thats about 180 gallons. I usually use 10 pounds per gallon to include the tank, water, and sand/rock which means that the two boards that are 96" long would have to hold ~900 pounds each. Using a 2X6, the beam would deflect ~1/2 inch in the middle. I prefer to see less than 1/8 inch worth of deflection. To achieve that you would need to use a 2X10 for the top frame. The rest of the stand could be 2X4.

If you wanted to build the top frame out of smaller material, a single leg in the middle of the long side would allow for using 2X6 as the top rail with a deflection of only ~1/16 inch but if you used 2X4 with just one leg, the deflection jumps up to 1/4 inch.

So, if you want to use 2X6, incorporate a center leg. Otherwise the stand will need much larger lumber.

HTH,
RocketEngineer

 

[flamron]

Thanks Rocket - ignore the message I just sent you.

 

[TheFishMan65]

RE, I am confused. Would a 4 ft 90 need to be 2x6s? According to the original post (IIRC and understood) then 2x4 are ok. Why then is one center support not enough for a 180? Seems like it would be the same as two 90 next to each other.

Thanks

 

[RocketEngineer]

RE, I am confused. Would a 4 ft 90 need to be 2x6s? According to the original post (IIRC and understood) then 2x4 are ok. Why then is one center support not enough for a 180? Seems like it would be the same as two 90 next to each other.

Thanks

You are right, I kept the 900 pounds instead of dividing it by 2 again....

Its friday.....

At 4 ft, a 90g only places about 450 lbs on the main rails which results in a deflection of .12 inches. A 4ft 120g should use a 2X6 top frame because at 600 pounds a 2X4 deflects .16 inches. But most folks rely on the strength of the tank.

So flamron, if you use a center leg you could get away with having the entire thing out of 2X4. If the leg is off center, then go to 2X6 to be safe.

RocketEngineer

 

[flamron]

Cool!

That might just work if I can do it all in 2x4.

Not sure if it makes a difference, but this tank won't have any rock in it. It will be mainly coral - possibly a few pieces of rock for hiding for fish, but nothing like a typical build.

Thanks!

 

[C-Rad]

That's all assuming that the glass bottom of the tank is strong enough to support all the weight without sagging (and cracking) while only being supported around the edges. The glass of the bottom would need to be super thick with such a large unsupported surface area. These dimensions sound like a custom tank, and maybe not a design that has been proven to work when only supported around the edges. If there's any doubt that the bottom can handle it without more than edge support from the stand, then you'll need to rethink the stand design. The design in this thread assumes that edge support is enough.

 

[flamron]

I'm planning to use foam on top of a plywood top for the tank, so that should help distribute some of the weight.

FWIW, it is a glass cages tank I believe. I'm not positive, but I am basing that from seeing other glass cage builds.

 

[C-Rad]

Plywood will help, but it flexes more than you would want your glass to flex, so without support under the plywood, you're still asking a lot of the glass. Glass Cages tends to over-build their tanks, but you might want to measure the thickness of the bottom, and call or email them to confirm that a tank with those dimensions, and that bottom thickness, is okay to support only on the edges.

 

[Floyd R Turbo]

I would double-up the 2x6s and run a third set across the middle, then put in cross bracing between them at regular intervals, and get 3/4" ACS plywood and do 2 layers, then foam. That's what I'm doing for the tank I'm having Miracles build to replace the tank that cracked, they said it was good enough to honor their 5 yr warranty.

 

[Floyd R Turbo]

I'm designing a stand for the tank mentioned above, which will be 66" L x 21" W x 24" H Miracles rimless. So I'm doing like I said above, 3 double 2x6s, etc. This is going into a recessed wall space that was specifically made for the original tank, so the stand will be secured to the wall or additional framing on 3 sides and the floor is slab on grade concrete with low-pile office carpeting on top (and pad, I assume).

I haven't asked the owner if he cares about the carpet/pad (it's probably glued down) but would I be able to remove the bottom framing and just have the legs terminate onto the carpet? I see no need to spread the weight of the tank across a concrete floor, or am I missing something?

 

[C-Rad]

Doubling the 2x6's seems like overkill to me, but it won't hurt. If you screw the double plywood sheets together every 10" or so, that will keep them from sliding against each other when one of them tries to bow, making the platform much more rigid.

If we're talking about concrete with dirt under it (a slab) then no, you don't need to spread the weight out. But Those lower horizontal pieces do more than just spread the weight out. The piece that each of the four pairs of legs screw into, also screws into the upper and lower horizontal piece. If two screws are used at each end of that piece, then it helps prevent "wracking", by helping to hold the legs rigidly at 90 degrees. If you don't skin the stand, you might really want that extra protection against wracking.

 

[C-Rad]

accidental double post. Can't delete it. Sorry

 

[TheFishMan65]

Bit late, but thanks for double checking RE. I always wonder if I understand someone elses design.

For a 36 inch wide tank I agree with Trubo about a center brace, but I don't think doubling is needed. This tank is only 12 inches tall. Still a lot of weight, but the PSI is half what most tanks are.

 

[reefermad619]

Hey rocket. I have a Q for you. I'm planning to build a 180 (6x2x2). What would the deflection of the top beams be if I used a 2x8? 2x10s? I know 2x8s should be ok, but I'm just wondering if it's worth it to build using 2x10s. Thanks for all the help. I used this guide to build a stand for my old 80 and I love this design. Thanks again.

 

[Biggar]

How do i insert a picture directly in the thread. It only allows me to add inserts that you need to click on?
Thanks Mike

 

[Biggar]

Finished 75 gallon stand! Love it

Finished 75 gallon stand! Love it

Made it much taller than regular standard stands. MUCH BETTER:spin1:

 

[Floyd R Turbo]

How do i insert a picture directly in the thread. It only allows me to add inserts that you need to click on?
Thanks Mike

You get a photobucket account or another service like that, then you insert the IMG code

 

[BigEarn86]

Things to note:

A 2X4 is actually 1.5" X 3.5"; a 2X6 is actually 1.5" X 5.5"; and a 2X8 is actually 1.5" X 7.25".

Making a beam made up of two boards side by side is twice as strong as each of the individual boards. For a 48" span, a 2X4 supporting 1000#s deflects 0.269" while a 2X6 only deflects 0.069" and a 2X8 deflects 0.030". That said, it is much better to go up in size then it is to double up.

When assembling the stand, be sure all of the pieces have square cut ends and that they are as straight as possible. If one of the long boards for the top frame (red above) has a crown (bows up when stood on edge), be sure to place the crown up. Glue will help bond the pieces together and coated decking screws will resist rusting. Clamping the pieces together and pre-drilling the holes will help make assembly easier.

Pocket drilling the legs (purple) can eliminate the need for the screw strip (green) but I would make sure to skin the stand on three sides to keep it from racking/twisting. Also, be sure to screw both leg pieces together on the corner for added strength.

If I skin my fame (for a 57g 36X18) with select pine 1X3/4/6's, using brad nails, glue, and clamps will the pocket screws (6 screw per leg= 3 upper & 3 lower) which replaced my scew strips provide enough support to keep my stand form laterally collapsing?

Secondly the very small gaps that may be seen under the bottom edge of the tank and the top of the upper frame can only be eliminated by sanding/planing the 2X4's true? If so, how much success has anyone had with that? Thanks.

RE, great thread and thanks man, my wife may hate the mess in the garage, but she would hate it even more if may tank set around empty for any longer!

 

[RocketEngineer]

Hey rocket. I have a Q for you. I'm planning to build a 180 (6x2x2). What would the deflection of the top beams be if I used a 2x8? 2x10s? I know 2x8s should be ok, but I'm just wondering if it's worth it to build using 2x10s. Thanks for all the help. I used this guide to build a stand for my old 80 and I love this design. Thanks again.

A 2X8 will deflect ~0.09" for a 180G tank. There is no need to go bigger.

RocketEngineer