Is there risk my tank stand will collapse?

[lazarus]

i had a custom tank stand built about 6 yrs ago for a 110 g tank. i built a refugium into the bottom which ended up with little clearance from the bottom of the DT. Over the years, salt buildup caused some warping of the plywood above the fuge. I glued some plexiglass above the fuge to mitigate this, but a year later it is still causing deterioration around the edges of the DT floor. I am getting very nervous about this. I cannot see this condition lasting forever and worry about a disaster looming. Is there a solution to this or am i worried about nothing? Any experience with tanks falling through their stand?

 

[tangs rule]

Some pics will help - but deterioration of plywood is a problem, cause it's about impossible to stop while there is a live tank atop the stand. Depending on where it's softening, and how much determins how critical it may be or may become. However I'd think eventually enough plywood delam will affect the integrity of the stand structure because if any of the vertical braces become unstable - that'll be the "point" you'd not want to cross.

 

[novahobbies]

I agree with TR....some pics will be necessary to let the stand gurus help you decide.
Honestly, a plywood cap for a stand should never be built as a structural element -- the tank should be able to safely lay on top of the framing members alone. I've seen many stands where the cap is purposefully left off, and you can see the bottom of the tank from up inside the stand.
If your cap is being used to help tie the framing members together, then my guess is you will have a problem. Without pics, I would urge safety and advise that you consider breaking down the tank now to remove the cap and replace it completely. You could possibly reinforce it from below but without pics I wouldn't want to say with certainty.
If you're handy, now would be the perfect time to just build a new stand. You mentioned you had very little clearance for your fuge; well, this is just the excuse you need to add some height inside the stand! It would certainly make sump maintenance that much easier!

 

[lazarus]

Here are the promised pics...the first two are on the left side of the tank showing the struts holding up the DT shelf. The shelf is deteriorating from salt vapor in the bottom chamber where fuge is located. The second two show the right side where you can see the plexiglass i installed to mitigate the rate of deterioration. It would seem the struts running up and down each corner would provide the support necessary to prevent total collapes when/if the bottom became completely warped....but i cannot tell. Please help with any assessment you can provide. i cannot locate the person that built the stand originally. Would you recommend I simply install extra 2x4 struts along the sides?

 

[tangs rule]

Well i need more data:
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is this 3/4 or 1" ply and is it 5 ply sheet
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are there no solid wood like 2x4 vertical supports? anywhere?
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and how many vertical ply supports are there?
are there any "gusset" or corner supports in the shelf-to-vertical walls? or does the shelf just sit atop the stand or is the shelf nested within the stand?
You can check for delaminated/soft areas by using a LARGE coin or small solid stone and "tapping" the wood......a solid area will sound kinda "solid" or dense where as a soft area - delaminated region will have a "hollow" / "tin can" sound to it. This is called tap testing and by using this method how much of the shelf is soft? and any vertical walls sound soft? You cannot tap test the area covered by the plex sheet - it will sound "dead" or hollow" ..pay VERY close attention to delam or soft areas in the vertical walls - they all appear to by ply and if so they are very load bearing.
Is this stand made of all plywood walls/floor/shelf/vert supports? no solid wood?
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here are your pics with some more questions....



and finally - does it appear that the whole thing was assembled with any glue on the joints/seams/surfaces or no glue AND is it screwed or nailed together?

 

[tangs rule]

Also - post a picture of the whole thing - cabinet doors open so I get an idea of the overall layout AND tank dimensions too so I can figure weight.....how thick is your glass too?

 

[lazarus]

OK - i owe you alot more info and pics. i will try to get these to you asap but am going out of town next week. Will do my best. Meanwhile, i can tell you the hole you asked about above is not a hole (pic 2). it is the refugium. that picture is actually upside down to show you the strut holding up the DT "floor." i have not seen any splits in the wood or nails in the wood. i think its all glue - is that even possible? the only serious delamination seems to be directly above my sump pump that sits inside the fuge. the clearance here is < 3 inches and so the salt vapor here goes straight to the plywood. that is why i put the plexiglass above it and across as much of the plywood as i could. hope this helps and appreciate any advice.

 

[aquaknight]

Do you know how much you have to top-off? It looks like maybe you have a ATO hooked up? If you do, and don't know how much, disconnect/turn it off and see how much the tank looses per day.

 

[tangs rule]

Quote:
Originally Posted by LAZARUS http:///forum/thread/386871/is-there-risk-my-tank-stand-will-collapse#post_3400587
OK - i owe you alot more info and pics. i will try to get these to you asap but am going out of town next week. Will do my best. Meanwhile, i can tell you the hole you asked about above is not a hole (pic 2). it is the refugium. that picture is actually upside down to show you the strut holding up the DT "floor." i have not seen any splits in the wood or nails in the wood. i think its all glue - is that even possible? the only serious delamination seems to be directly above my sump pump that sits inside the fuge. the clearance here is < 3 inches and so the salt vapor here goes straight to the plywood. that is why i put the plexiglass above it and across as much of the plywood as i could. hope this helps and appreciate any advice.
Please more pics and dimensions - but I'm figuring 1200-1400 pounds total tank weight. (650# water, 250# tank empty weight, 300-500# in rock&sand)
I'd really think & hope its at least stapeled or finnish nailed with glue.....screwed together is best - but in either case, someone may have "put putty" or finnish over the fasteners to cover them up.....glue alone would really make me nervous.

 

[novahobbies]

My gut feeling is still the same for this -- you're probably not in any immediate danger for the next month or two, but I would strongly suggest having a new stand built NOW. I really feel that you'll be better off just doing a new stand as opposed to trying to reinforce the original problematic one. Make it taller to accommodate your sump while you're at it....

 

[notthelameball]

Make one out of that tree that got struck by lightning in the aquarium section!

 

[lazarus]

Sorry for the delay in response. Tank dimensions are 22W x 44L x 24T.
I cannot find any nails on the unit. As you may recall, I put a sheet of plexiglass on the underneath floor of the DT when I saw the sump pump was creating so much humidity. This seems to have done a good job of preventing delamination. However there is a spot in the back that the plexiglass did not reach, and in this spot there is significant delamination. I cannot find evidence of it anywhere else on the unit.
It seems the entire unit is made of laminated wood. I count 5 light bands and 6 dark bands in the wood. The main struts are 3/4 inch thick.
I will be posting more pics once I can figure out how on this particular machine.
I appreciate your advice. I would prefer not to build a new stand. Its not the expense that concerns me so much as the stress to fish and my bad back.
Thank you.

 

[lazarus]

 

[snakeblitz33]

When in doubt... redo it.

 

[tangs rule]

IMO - for now your likely OK - but I'd begin looking at a replacement stand or beefing it up. Because it is all ply construction, and with more time/age, any areas of delam/softness of the wood will continue to grow. Your stand currently displaces ~ 230 pounds/sq ft floor loading but the vertical panels (ply) carry all of the ~1600 pounds of the system weight.. At the very least - i'd add some 2x4 solid wood vertical supports in the center - say one in the front & one in the back & tye them into the front/back panels with good long screws.