# [Wet Thumb Forum]-keep the stand or start from scratch



## kazador (Feb 24, 2004)

since im not the greatest with woodworking, i went out a bought 2, 2foot long kitchen cabnate from home depot, and put the obligatory top on. my problem is that the top is only supported on the sides and even with out water in the 75gal, the top of the stand is sagging in the middle. being that there are 2 sides put together in the middle, could i just add some wood to keep the middle from sagging? or does the entire length of the tank need support, can i get away with both ends the the middle with support?


----------



## kazador (Feb 24, 2004)

since im not the greatest with woodworking, i went out a bought 2, 2foot long kitchen cabnate from home depot, and put the obligatory top on. my problem is that the top is only supported on the sides and even with out water in the 75gal, the top of the stand is sagging in the middle. being that there are 2 sides put together in the middle, could i just add some wood to keep the middle from sagging? or does the entire length of the tank need support, can i get away with both ends the the middle with support?


----------



## Roger Miller (Jun 19, 2004)

You need to support the whole length of the stand. The top needs to be flat and the whole stand needs to be rigid.


Roger Miller


----------



## kazador (Feb 24, 2004)

hummm, roger, do you think getting a steal frame made to the size of the tank and putting it under the top of the stand would work? to top is presboard.


----------



## imported_pineapple (Apr 28, 2004)

Companies like the catalogue woodworker's supply www.rockler.com sell great steel workbench legs which can be configured to support any size aquarium. I think they are elegant and certainly take away the fear of collapse which sometimes accompanies the use of furniture. You can also cover the legs with quality wood or plywood thereby making a sturdy cabinet. These legs support several thousand pounds in weight - check the literature or the web site. Here is a link to one such item:

http://www.rockler.com/ecom7/product_details.cfm?&offerings_id=5953

There is another source which is slightly better but I cannot lay my hands on the catalogue at this moment.


----------



## kazador (Feb 24, 2004)

thanks for advice pineapple, i might use those if a make another stand. but im not realy worried about it cloapsing, im concerned that the tank is not fully supported on the bottem and will break, spilling 75 gal of water and fish un happly on my living room flore. let me clearify the curent set up. i have 2 two foot long free standing kicthen cabnates side-by-side, with a counter top on top of them. i am worried that the conter top will not be stiff enuf to stay riged, and there fore leve th e tank with no center support. my tahught of a solution would be to lay 2x4 lumber across the top of the cabnates befor putting the counter top on, there fore elminating any posible sag.


----------



## imported_pineapple (Apr 28, 2004)

Ah, I see. In construction, load-bearing gaps, like over doors and windows, are most often spanned with laminated material such as multiple layers of plywood. Your could add some sort of wood layer using screws to bolster the flat top. I have one cabinet which uses this method and holds its own against a fairly large load of water.


----------



## kazador (Feb 24, 2004)

thankx for the advice pineapple. do you think 2 layers of 1/2" birch plywood glued together would provide enuf strength for a 75 gal? there are struterl supports at the ends and in the center, so i only need to support about 1 foot on eighter side of the center of the tank.


----------



## JamesHoftiezer (Feb 2, 2003)

I laminated/glued two 3/4" MDF board together under by 100g. It si complete over kill. You could certainly get by with less, even a single 3/4" board may work or glue two 1/2 together. 

You'll find the MDF is VERY easy to work with especially if you plan on routing the edges. Before psinting you should you some sand paper to rough the surface.


----------



## JamesHoftiezer (Feb 2, 2003)

Pineapple,
Thanks for the link on the workbench legs. 

You can also get them through local industrial supply houses. The legs I use are $42/set and are rated at 4000lb


----------



## Markw78 (May 6, 2004)

What is the cabinent top made of? Its likley stong enough, you don't have the full weight in any 1 spot, its spread out across the tank, mostly around the edges...though acrylic tanks do need to be braced to prevent bowing. Most commercial glass tanks rest on thier trim and not the tank itself.

And I have no idea about glass tanks without trim


----------



## kazador (Feb 24, 2004)

thankx guys for all the advice. james, were there any gaps under the tank? if so how big? the way my tank sits on the stand the 2 sides, back wall, and center(frunt to back) are the only parts of the tank with wood under them. i know im probluy being way over caushes, but i want to make shure i's not going to breake the tank.


----------



## JamesHoftiezer (Feb 2, 2003)

My tank has the normal rim as well as a cross brace underneath. Normal stands assume only perimeter support. 

For my tank I got a 1/2" thick sheet of insulation foam and put it under the tank. The weight forces the foam to conform and it supports the perimeter rim, cross braces and the glass. 

99% of tanks are made to be set on fla wood or a perimeter stand. The foam is just me being overly cautious.


----------



## kazador (Feb 24, 2004)

james, i just looked at your "parts and construction" post, on your stand are the virtical supports out side the primiter of the tank? ie. no support directly under the tank rim? tankx?


----------



## JamesHoftiezer (Feb 2, 2003)

On my stand... taht is a true statement. My tank is drilled in the back. The supports would get in the way. 
The thing to stress is that the top of the stand (i.e. table top) is 1 1/4" thick. It could support many times the weight on my aquarium.


----------



## dennis (Mar 1, 2004)

Suprisingly, 

one key here is the Laminating of 2 peices together. ANytime you glue 2 peices of MDF(or similar things together) it will be much more rigid than any single piece alone. 2 3/8" pieces of MDF, gkued together, would be much stronger than a single sheet of 3/4". MDF will sag over any substantial distance when used horizontaly. This assumes all the weight is in the middle though. If the weight of the tank(usually the outer rim of hte tank itself) has a support that will bear weight, ie touching the floor, then I would not wory as long as that support was located with 5-6" of the frame.

Your 75 gallon probably weighs between 650-750 lbs. Most of this weight is aroung the rim of the tank. If you figure the rim is 1" wide then the 700lbs is being supported on ~130 sq inches. This translates to ~5psi on the top. You would be fine as long as the top is supported along its length. If your top is already sagging, then find a way to support it and make sure it is flat.

Hope that helps


----------



## JERP (Feb 4, 2003)

Am I the only one worried about using MDF in a damp environment, like say, under a fish tank? This stuff dissolves at it absorbs water. Under a heavy load it would deteriorate quickly. I realize kitchens cabinets use MDF, but kitchens are a much more controlled environment and doesn't support the load of an aquarium.

I would recommend using wood frame with MDF facing.


----------



## imported_MatPat (Jan 18, 2004)

I wouldn't worry about using MDF in a damp location as long as it was properly primed and finished. I have several work surfaces/benches in my garage that are 2 layers of 3/4" MDF and finished with polyurethane. They have withstood many cold drinks and various spills that have been left overnight without swelling or showing damage. 

As far as the kitchen cabinets, they are more than likely constructed from particleboard instead of MDF. Either way they should be fine. 

Most stands you can buy in WalMart, PetSmart, etc are actually laminated (with formica type faux wood grain) pieces of 3/4" particleboard that are held together with knockdown fasteners. Most only have a 3/4" top also. 

Your countertop is probably constructed of particleboard also, either 1/2" or 3/4" with bracing around the perimeter to make it look thicker, and a laminate surface on it. As long as this bracing rest on your cabinets, you should be fine. It may or may not have a center brace running from front to back. If it doesn't, I would add one to keep the center from sagging. Just make sure to place this brace in a position where it is over the two cabinets. I have seen 4' spans of both MDF and Particleboard sag under their own weight (empty bookshelves come to mind). 

If the top sags water will collect in the low areas. This shouldn't be a problem with a high pressure laminate made for a kitchen countertop. It could however be a problem if the water makes it's way into the untreated ends of your MDF/Particleboard cabinets, either over the front/back edge of the countertop. 

If you are taking the countertop off to brace it, I would coat the unfinished ends of the cabinets and also the bottom of the countertop with a good primer and paint. It may be overkill, but I'd rather be safe than sorry. 

You should be fine with the cabinets themselves since, like Dennis stated, the weight of your tank rests on the rim and not across the whole bottom of the tank. IF your tank has a center brace on the bottom that actually rests on the countertop I would definately add some bracing to the countertop. 

Hope this helps.


----------



## kazador (Feb 24, 2004)

tahnks guys for all the help. i recently had a cabnate maker over, same one who is building my costume hood. and he says that with center bracing all will be well. again thakx for all your advice


----------

