Wood stand question

[boacvh]

Hi. I have a stand design question for you all.

I am planning an upgrade to a custom 96x24x24 tank. There is a tank manufacturer I am considering with great reviews here that says they won't guarantee the tank unless I use their steel stand.
I understand them not giving a guarantee if I use my own stand and that's ok. That's not the issue I want to discuss though, the issue is they say if the stand is made of wood, they can pretty much guarantee the elements will shrink in time and that if they don't shrink at the same pace and to the same extent, the tank will "split open". Talking with a few people around here they said my wood stand looks ok to them and no issues for a 240g tank.

Any thoughts on this? I of course got concerned with the "split open" comment. is this stand really that concerning and should I get rid of my stand and upgrade to steel? I think unnecessary, but wanted to make sure since I have never designed or built a stand before. Below are some pictures and some drawings @Reefer Reboot helped me put together (ignore the red and ignore the plumbing that's just a test)
(Also, please keep with no manufacturer names here. I want this discussion to be about my stand and NOT about manufacturers and their policies.)

Thanks!

 

[Mark Novack]

It looks fine and strong. I use steel but I still use a 1" board of purple high density insulation under the tank per manufacturer's instruction. My tank has a two piece bottom and that's their method for even settling. Before I did use a wood cabinet for 540 liter tank. No problem but it did weight 400ish pounds.

 

[KStatefan]

How far back will the tank go?

 

[Paul B]

I built mine out of red wood because it shrinks the least of the available woods and it resists rot and moisture damage. It is 6' long and I purposely built it with almost no "wood on wood" contact. I didn't want to "sandwich" any wood together because moisture gets in between boards and never dries so it eventually rots.

All the hardware is hot dipped galvanized, 1/2" carriage bolts and on any structural part the bolts are all the way through with washers and nuts on the other side. I also used waterproof wood glue.

The legs are cut out on top to hold up the horizontal pieces and the hardware is just to hold the thing together so it is strong by design and not by adding additional pieces.

I built most of it out of 2X6s so they are strong enough. The legs are 4X4s. My 125 gallon has been on this stand for 5 years now.

I like heavy lumber and simplicity.

I am a commercial construction electrician so I built many things over many years for very heavy equipment.

 

[boacvh]

How far back will the tank go?

24 inches. And sorry, thats a change I already made and forgot to mention. From the front to the wall is around 32 inches. I moved the back supports so they sit right below the tanks edge

 

[boacvh]

I built mine out of red wood because it shrinks the least of the available woods and it resists rot and moisture damage. It is 6' long and I purposely built it with almost no "wood on wood" contact. I didn't want to "sandwich" any wood together because moisture gets in between boards and never dries so it eventually rots.

All the hardware is hot dipped galvanized, 1/2" carriage bolts and on any structural part the bolts are all the way through with washers and nuts on the other side. I also used waterproof wood glue.

The legs are cut out on top to hold up the horizontal pieces and the hardware is just to hold the thing together so it is strong by design and not by adding additional pieces.

I built most of it out of 2X6s so they are strong enough. The legs are 4X4s. My 125 gallon has been on this stand for 5 years now.

I like heavy lumber and simplicity.

I am a commercial construction electrician so I built many things over many years for very heavy equipment.

Thanks @Paul B !! May I ask, if this is just the last 5 years, what did you use for the other 50ish years of your tank? Wood as well? Did you build this one just because of your last move or issues with past stands?
As always, thanks again for your feedback!

 

[Paul B]

My last stand was a construction material called "Kindorf". It was 3" wide for the horizontal pieces and 1 1/2" for the legs. Hot dipped galvanized and very strong. The tank was on that for about 40 years but I had to replace two of the legs due to rust.

This is one leg. The leg in the foreground is old but I put that new leg behind it because I was afraid the rust would weaken it. Metal and salt water won't last long unless it is stainless steel.



My new wooden stand looks like the day I built it but that is because of the hardware I used and the fact that I have very little wood sandwiched next to each other which is a recipe for trouble.

Also, unless it is "marine plywood" I would not use plywood even if it is exterior plywood which just means it won't fall apart for the time it takes to build a house and not meant to be wet for long periods of time with freshwater, not salt.

Pine is also a terrible wood to build anything out of even if it is pressure treated which just means it won't rot for 25 or so years but it is usually a poor grade of pine that is pressure treated so it warps pretty bad and you don't want warping under glass.

Redwood is strong and warps the least out of the available woods. It is expensive but not terribly so. I built the legs of mine out of pressure treated wood because it doesn't noticeably shrink vertically but I would have used redwood for the legs if I could get it, but never put two pieces of wood together to make it stronger. Just buy the correct size wood in the first place unless you are building a house.

 

[Sisterlimonpot]

I doubt you will have issues with your stand design. There are some structural red flags in the construction that I would've avoided.

However, here's the issue I have with not using the manufacturers stand. And it's sort of a catch 22. I have all the confidence in the world that a wooden stand will not split a seam due to expansion and contraction rates of the materials. It's all the "what ifs" involved. You take a huge risk when a company tells you that your warranty is voided unless you use our stand. There can be manufacturing defects that have nothing to do with metal vs wood stand, but they will hang their hat on the fact that you chose to use your own stand and it will be their prerogative to do so.

 

[Reefer Reboot]

I guess I still can't talk you into an extruded aluminum stand, can I?

 

[Lost in the Sauce]

This is a major design flaw in my opinion. The weight of your tank and water are relying on the fasteners holding the 2x6 stiles into your long rails.

Creating a bridle joint of sorts by fitting a 2x6 outside of your upright would allow those to carry most of the load. Not metal fasteners.

 

[Paul B]

I feel the major flaw is all the wood that is sandwiched to other wood creating so many places where water penetration will get sucked into and never dry. I forgot the term where water gets sucked into tight places but I am sure someone Knows it. I also would never rely on wood screws for anything associated with salt water unless they are deck screws but they are for holding decks down and don't really have much lateral strength.
Just my opinion of course.

 

[boacvh]

I guess I still can't talk you into an extruded aluminum stand, can I?

I am certainly open to it. But only if neccesary to get rid of my current one! LOL

 

[homer1475]

Wheres @RocketEngineer when you need him?

 

[boacvh]

This is a major design flaw in my opinion. The weight of your tank and water are relying on the fasteners holding the 2x6 stiles into your long rails.

Creating a bridle joint of sorts by fitting a 2x6 outside of your upright would allow those to carry most of the load. Not metal fasteners.

Thanks for the feedback, and pointing out these flaws.
Trying to understand what you meant with "Creating a bridle joint of sorts by fitting a 2x6 outside of your upright". Sorry total noob here.

 

[boacvh]

I feel the major flaw is all the wood that is sandwiched to other wood creating so many places where water penetration will get sucked into and never dry. I forgot the term where water gets sucked into tight places but I am sure someone Knows it. I also would never rely on wood screws for anything associated with salt water unless they are deck screws but they are for holding decks down and don't really have much lateral strength.
Just my opinion of course.

Thanks Paul, I'll see if I can come up with a way to minimize/change these "sandwiches"

 

[boacvh]

I doubt you will have issues with your stand design. There are some structural red flags in the construction that I would've avoided.

However, here's the issue I have with not using the manufacturers stand. And it's sort of a catch 22. I have all the confidence in the world that a wooden stand will not split a seam due to expansion and contraction rates of the materials. It's all the "what ifs" involved. You take a huge risk when a company tells you that your warranty is voided unless you use our stand. There can be manufacturing defects that have nothing to do with metal vs wood stand, but they will hang their hat on the fact that you chose to use your own stand and it will be their prerogative to do so.

Thanks. Yes, that certainly scared me. However, they seem to have great reviews here from people that didn't use their stand so that gave me some comfort.

 

[Lost in the Sauce]

Thanks for the feedback, and pointing out these flaws.
Trying to understand what you meant with "Creating a bridle joint of sorts by fitting a 2x6 outside of your upright". Sorry total noob here.

Adding a piece of 2x6 here that sits on top of your bottom rail, and tightly allows the top rail to sit on it, screwed to the current upright, is what I'm describing.

 

[homer1475]

You want your top rails to sit on the vertical legs. This way all the weight is pushing on the verticals and not relying on screw strength to hold it up.