90 gallon build (DIY plywood stand)

[Sinclair81]

I am finally starting the build of my 90 gallon tank that I aquired over a year and a half ago. I got the tank, stand and rubbermaid sump and pump for 75 dollars, after I bought it it sat in my garage, mainly because the stand that it was on was to short and hideous, so I needed to build one, so it begins...
So it began as two sheet of plywood, one oak, one regular ACX.

Then measured things out and made cuts with a circular saw.

 

[Sinclair81]

I then realized that I had 48" by 96" plywood and a tank that was 48.5" wide, so I was planning on just simply screwing the ends of the "box" together, but this would leave my stand short. So I decieded to rabbet join the "walls" together. To do this I needed to router out 2/3's the way through the plywood. What would be a simple task with a router table, but I had to improvise, so I ended up using my router with a 3/4 inch bit and a 1 by 4 as a guide, I routed all the sides.

After all the "walls" and top and bottom were routed, I used a kreg pocket hole drill to make holes to screw all the parts together

Then she came together...

I can see it all now!

 

[Bretts05jeep]

Are you going to add doors to the front?

 

[Sinclair81]

Yea, the idea is to cut it out and have one single large door, trimmed and held on by magnets, but we will see how that goes.

 

[Ron Reefman]

I really hate to be a nay sayer, but I wouldn't put 750 pounds of water on top of that stand in my house if you paid me. Maybe you know exactly what you are doing, but it looks scary to my eyes. I can't say I have ever seen a stand to support a 90g tank that doesn't have some kind of 2x2 or 2x4 structure inside... have you? It will hold your tank fine when you set it up. And it may even last for years. And you have done a fine job with making it 'look' great... but IMHO a plywood structure is no way to support 750+ pounds of water and glass. At the very minimum I'd add 2x4 structure around the inside of the base, 2x4 legs in the corners and a 2x4 rim inside the top. Plywood really doesn't hold up well when loaded on edge and it really doesn't like getting wet. I know you never intend for it to get wet, but that's a bet I wouldn't take. And adding doors to the front, especially one big door rather than 2 smaller doors with a center support will only make this structure even weaker. Do yourself a HUGE favor and read this thread (the basic design is about the 3rd post down).

http://www.reefcentral.com/forums/showthread.php?t=1567110&highlight=rocket+scientist+stand+design

Your workman ship is beautiful and the stand looks incredible. But again, IMHO, your engineering of the support structure is really lacking. It may hold up just fine, but I wouldn't bet 90g of water in my livingroom on that structure. I'm not a structural engineer, so take my opinion for just what you paid for it. And I honestly wish you the best of luck.

 

[RA]

I have to agree with Ron. I think you did a nice job of building it, however I don't think it is structurally sound. It may hold the downward force of the weight of the water, but if someone bumped into it I think it would go sideways in a hurry.

 

[Ron Reefman]

One last thought. I know the routed wood has slightly more surface area than just 3/4" plywood, but glued and screwed butt joints of 3/4" plywood just does not have the shear strength you need. Screws can be pulled from the end grain of a piece of plywood much easier than from a solid piece of pine. And they can also be twisted sideways and ripped out of the edge on pieces. I'm not trying to be the bad guy, I just don't want you to have a massive failure in 6 months or a year.

 

[john rochon]

The routed joints are not butt joints anymore. There half rabbits I believe?
That stand is perfect and can hold much more than the tank filled.
no different than what tank manufactures recommend and probally better!

 

[cjk76]

Please, please, please add 4x4s to the corners and a couple of 2x4s between them to make it more sturdy. 1 2x4 at the top and bottom of each side would be fine to hold the 4x4s together. No need for a 2x4 at the bottom of the side with the door.

I really hope you don't loose your beautiful tank to a miscalculation when planning the stand.

 

[sponger0]

I wouldnt trust that stand....im sorry. Ive built all my own but your looking at a minimum of 900 lbs of water, rock, sand, fish, and coral. Thats your decision but just giving my opinion

 

[rovster]

Its funny watching the different opinions. There have been many plywood stand builds and the consensus is that most on here overbuild things and plywood should theoretically be OK. Most of the stock stands at the LFS are made with plywood and some with 1 x 4. I've never seen a 2 x 4 or larger. I'm not an expert, but its funny how some see this as so far out of the box (haha, pun intended). Continue please.......

 

[sponger0]

Its funny watching the different opinions. There have been many plywood stand builds and the consensus is that most on here overbuild things and plywood should theoretically be OK. Most of the stock stands at the LFS are made with plywood and some with 1 x 4. I've never seen a 2 x 4 or larger. I'm not an expert, but its funny how some see this as so far out of the box (haha, pun intended). Continue please.......

The problem is just that...."in theory" I have experienced this phrase many times and in theory something should work...but I woudl rather be safe than have a broken busted tank. Call me crazy

 

[ChrisL1976]

I'll just jump in with the other guys. Add MORE support or buy a good wet/dry vac and increase your insurance. Put some 2x4's inside the stand you already have built. Beefing that up should cost you less than $20.

 

[sponger0]

Oh Ill add...in theory I prefer my tank inhabitants to not be on my carpet lol

 

[dadnjesse]

Yes there are lots of plywwod stands, but they still need a frame. All you have is plywood, again if you fill that tank and push on the side of your stand it's going to fall over. No one is putting you down were just trying to help.

 

[sponger0]

Yes there are lots of plywwod stands, but they still need a frame. All you have is plywood, again if you fill that tank and push on the side of your stand it's going to fall over. No one is putting you down were just trying to help.

I agree. No one wants to see a thread about a tank that fell over

 

[JMartin104]

What you need is four 12x12s on the corners with a 4x12 across the top. LOL I'm amazed at how overbuilt so many stands are and if it makes you feel better to think it's overbuilt, go for it. I've seen 2x4 stands fail where simple 1/2" plywood did just fine. It's not as much what you build with, but how you do it. The thickest piece of wood supporting my 110 is 1/2". Been doing great!

 

[funkyfish77]

Once you cut a big door in the front that is going to weakin ur stand a 2x4 band along the inside under the tank would help alot. My stand has a big door in the front held in by magnets they have held up pretty good over the years.
Good luck on the stand

 

[dadnjesse]

What you need is four 12x12s on the corners with a 4x12 across the top. LOL I'm amazed at how overbuilt so many stands are and if it makes you feel better to think it's overbuilt, go for it. I've seen 2x4 stands fail where simple 1/2" plywood did just fine. It's not as much what you build with, but how you do it. The thickest piece of wood supporting my 110 is 1/2". Been doing great!

Lets be reasonable, you don't need 2x4's or 12x12's but you do need a frame!

 

[Sinclair81]

Ha, this is great guys, thanks for all the input. I am putting a frame along the inside. I had planned to from the beginning, but did not want a huge 2X4 frame, way to excessive, so my plan is to "frame" the inside with 1X4's, which will give the overall thickness of the supporting frame an inch and a half. And for the record I did not put simple butt joints on the plywood, way to instable, I used Rabbet joints with glue and screws. MUCH more stable than simple butt joints.