Why DIY Stands Fail

[CHOMPERS]

...I think its safe to say...
...this is the stand for my 220 and it has no diagonal bracing.

:WTF: I hope you at least skinned it with thick plywood.

Overbuilding is the only way to go!!!

The MFK catch phrase?

My appologies, I am not sure if it was intended but your post came off as smug and arrogant. I placed sound engineering reasoning into the public domain for free. To get the same information from your local civil engineering firm would cost you in the ball park of $400. Be thankful for that. If you feel that you are immune to the worse case that can happen, the more power to you. I agree that there are crappy stands on the market out there; they will last long enough for you to lose the reciept. I have never seen a stand made of oriented strand board, but I have seen them made of particle board but only for tanks 55g and under. Particle board is a poor choice for handling compressive loads (especially after it has gotten wet) and worse for tensile loading, but unfortunately due to a cut throat market it has become the manufacturing choice material. It is extremely foolish to use a bad design and improper materials as a quality measure just because you saw it in a store. I took the time to post the above information because there is a need among MFK members who are "blind following the blind".

 

[dodgefreak8]

I think that you misunderstood my reply.. I do appreciate your information on the subject but it seems as though you are assuming that your engineering background makes the rest of us ignorant to the subject. I was merely stating that manufactured stands have also had some sort of testing done to hold the amount of weight they were desinged for and they have no diagonal bracing. I did in fact use 3/4" birch/maple plywood for my sheeting/ diagonal bracing. I wasn't saying that partical board was the material to use in stand building. I was actually mocking its use/ You stated that plywood and partical board was poor for holding compressive loads I agree but if you would have looked at my design further you would know that is not used for this purpose. the comressive load is on the frame not the sheeting.. I quess I am merely trying to state that some of us DIY are not as ignorant as some engineers take us for. Being in the construction field myself I have to deal with arogant engineers everyday that make just as many mistakes as I do. the only difference is I have to fix my mistakes. Please don't feel offended if this was not your intention your information is very informative to those starting to brave the DIY area of fishkeeping and there is nothing I enjoy more tha a good disscusion between enthusiasts..

 

[Reefcrack]

... I wasn't saying that partical board was the material to use in stand building. I was actually mocking its use/ You stated that plywood and partical board was poor for holding compressive loads I agree but if you would have looked at my design further you would know that is not used for this purpose. the comressive load is on the frame not the sheeting.. I quess I am merely trying to state that some of us DIY are not as ignorant as some engineers take us for. Being in the construction field myself I have to deal with arogant engineers everyday that make just as many mistakes as I do. the only difference is I have to fix my mistakes...

Granted the

compressive load

is on the frame, but the sheathing AND framing comprise the supporting diaphram that resists both the gravity loads and the shear forces. The sheathing material should be of a structural grade and should be attached on an appropriate nailing schedule. I believe that was what was intended. My concern would be the 4x4 headers you have running under the 2x4's. Without knowing any dimensions, trib widths, how many you have, how long they span, and how long a span those 2x4's are running we can only guess. Being in the construction trade, I'm sure this is not news to you. Keep in mind we are only looking at a couple of pictures and don't know if your stand is finished as shown, or there is more work to be done to it.

This is pretty serious business for those of us who deal with it on a daily basis. Nothing personal.

 

[dodgefreak8]

I think you are confusing my stand with the other in this post. My stand uses no 4x4's.

 

[Reefcrack]

Sorry about that Dodgefreak.
By the way, is that Dodgefreak as in Mopar. If so I hear you brother. I miss my Charger!

 

[dodgefreak8]

yeah is a mopar thing.. This little fish hobby has really put a damper on my dodge craving finacially if you know what I mean.

 

[GregB]

I made a stand for a 40 gallon and a 70 gallon out of osb and a few 2x4s I cut the 2 outside wider on the bottom kinda like triangles. and the 2x4s in the corners the tank sat right in snug and stayed that way for at least 8 years! I had to give away my setups when I moved 8(.. I just stained the osb and it didnt look half bad!! wish i had a picture of it to show yas.. Ill look see if i got one!

got a 73 Challenger in the back yard waiting to be reborn!!! MOPAR ROCKS!!!

 

[GregB]

BTW chompers!!! GREAT post!! I wasnt saying you were wrong. You sure know your stuff 8).

my stand held up fine but if I were going to go with anything bigger I'd build the crap outta it!!

We were building a house one time and had the lower floor braced but not plywooded yet.. We told a helper guy to clean up all the wood down below.. suddenly the house felt a little wiggly!!! WAIT NO NO NO DONT TAKE THOSE BOARDS OFF!!! hehe we stopped him in time!! thank god!

 

[CHOMPERS]

Sorry about that Dodgefreak.
By the way, is that Dodgefreak as in Mopar. If so I hear you brother. I miss my Charger!

Now Chargers are something that will get me so far off topic that I will never come back. My first car was the #2 '73 Charger. It was a Ralley Sport with a 440 w/ Carter Thermoquad. It had a red show room paint job (that looked puke orange under mercury vapor street lights). It also had the reflective side stripes that faded to different colors. My twin had a white and black 73 Ralley Sport Charger that he kept running into other cars. I sold him mine when I got the 4x4 bug, and he ended up trading it for a stereo. That guy ran the serial number (it had way too many zeros), and then had to tell my brother what an idiot he was for trading it for a stereo (it was a nice one). I had seen Chryslers advertisements with a car just like mine but never had guessed which car that really was...until I got wind of the #2 news.

 

[CHOMPERS]

DF8, no hard feelings; just some clarifications. In person I am sure we would have great conversations...in writing, our literary skills just suck. It is easy to write down your thoughts, knowing what you meant to say but through errors or ommisions, your reader takes a different meaning.

... you are assuming that your engineering background makes the rest of us ignorant to the subject...

No, it is my observation that there are a lot of stands without proper bracing. My background gives me a unique perspective as to what is overbuilt and what is not. It is an engineers job to prevent failure. My original post was prompted by a 700+ tank that was placed on a stand with no bracing; it was not even skinned. The gentleman finished his post with the statement that it was California earthquake proof. For most of us, our tanks only see static forces (no motion). It is the dynamic forces (motion) that no one thinks about. These forces include earthquakes, fat drunk buddies that lean on everything, and soon to be ex-girlfriends/wives that want to break your stuff (after all, it isn't like they can beat you up) (I hope not anyway).

By the way, plug your gallonage into the equation and calculate for your tank moving one degree. Ask yourself if you are content with the result. How much movement could occur after your stand ages ten years? After what period of time would you be content with losing your tank due to a failure in your stand? Of course that is a retorical question; that is why the world has engineers.

... manufactured stands have also had some sort of testing ...

You would be surprised at how little product testing actually goes on. That is why I made the comment that most stands will last just long enough to lose the reciept. A product may have a life time warrantee, but if you lose the reciept, you lose your warrantee. Have you ever seen a reciept from your local auto parts store that offers lifetime warrantees on their parts? (Advanced Auto Parts for the eastern half of the US, same company but different name for the west.) The receipt fades away to a blank piece of paper in about 6-9 months...and there goes your warrantee.
My experience with manufacturers testing involves directions from an MBA or some lower level of management (no R&D experience). Sure, I would also expect a prototype to be weight tested...fill a tank and then drain it (that static force but not dynamic thing again).

I did in fact use 3/4" birch/maple plywood for my sheeting/ diagonal bracing.

Now you are just making me jeleous

I wasn't saying that partical board was the material to use in stand building.

I didn't either. I hate the stuff. It is the material of choice in commercially produced stands because manufactures have to produce products for less than the competition and the public doesn't know any better. Stands in my area (55g and less) often support the tanks load exclusively with partical board. Yes, it will work for today....after some water is splashed out several times and is soaked up by the partical board, it becomes progressively weaker until your fat drunk buddy leans on it. I guarantee you that at that point you have already lost the receipt.

... but if you would have looked at my design further...

I saw that you were smart enough not to copy what you saw in the store. Between our writing and reading, some meanings were not conveyed.

...I have to deal with arogant engineers everyday...

Looks like someone hates engineers! In truth, when a student graduates at the bottom of his class, he still gets the same degree as the student that graduated at the top. This is part of the reason the world is filled with "stupid people" (the Peter Principle also applies).

[/QUOTE]Please don't feel offended...[/QUOTE]not at all