Sideboard like stand for 75 gallons (900 lbs) aquarium, will it hold the weight?

[Christoph]

Hi all, 

I am working on a stand for a 75-gallons aquarium. Filled and with all the attachments, a 75-gallons aquarium can weigh up to 900 lbs. Significantly more weight than our furniture has to support under normal circumstances. 
When my wife came up with the idea to upsize the aquarium to 75 gallons, I checked out the usual places for an appropriate stand.  What I found was not convincing to me, even though I know that many people use these commercially available stands to put their big aquariums on. A search for DIY stands found many examples made out of rough 2x4s held together by glue and wood screws. While they seem to serve the purpose well, their appearance was not what I envisioned for the corner of our living room where the aquarium will be located. 

I thought about a basic structure out or 2x2s (actual measurement) to safely carry the weight. By looking at the commercially available stands and without being an engineer, I assumed that a structure like that should carry the weight without problems. One 2x4 can vertically support a lot of weight. If I understand all these tables correctly, the weight can be more than 1000 lbs. Hence I assume that four 2x2 can support at least that amount of weight.

 Not entirely sure how to make the joints, likely glue, and probably dowels, but I could also use a Festool Domino jointer. 
I thought of some kind of castle joints or the like for the top corners. 

Unfortunately, I am getting second thoughts now. Can a structure like that really support 900 Lbs? 

Here is what I have in mind as a basic structure—just the structure without the top, doors, and the like. 

Appreciate all thoughts

Thanks

Christoph

[Chestnut]

So a piece of wood stood on end where you are loading into the end grain can support a lot of weight. I'd say the design you have drawn up could easily support an aquarium.

In a standard leg and apron configuration, like a table. The top sits on the leg and a good portion of the weight is supported directly by the leg. Some weight is supported by the apron but it isn't even close to the full weight. So while I'd make sure to make secure apron joints don't assume that they need to be something extraordinary. Also keep in mind that the weight of an aquarium is evenly distributed. If you have 1,000 supported by 8 legs and 16 joints, that's 125 lbs per leg. The apron joint will only support a fraction of the weight that is directed at the leg so even if it's 50% of the weight directed at the 16 joints that's only a bit more than 30 lbs but it's likely less. That's really not that much weight in the grand scheme of things. Me leaning back on the rear 2 chair legs is straining joinery FAR more.

If it were me, I'd make this a frame and panel design with the 8 legs like you have outlined. I think your design is really good. I would just do a floating M&T (domino) to connect the aprons to the legs. I'm assuming your doing doors for the 3 openings. For the panels I'd do plywood and would glue it into a rabbet that is cut into the legs and aprons. This will make a VERY stiff VERY strong system. The plywood would also support the apron and will direct even more force from the apron into the leg. The Sideboard i built is somewhat similar and I wouldn't hesitate to put a 1,000lb aquarium on top of it. Page 2 shows a bit on how i made the rear of the sideboard with plywood in a rabbet, this is how I'd handle your construction.

[wtnhighlander]

I'd go with @Chestnut's advice... After all, he IS an engineer!  

[Chestnut]

Oh you'll likely want a top on that or something to set the aquarium on. Your gut may lean plywood but in this situation solid wood is likely better.

[Christoph]

Hi,

 

Thank you for your encouraging input. I checked your sideboard build, very nice, and I certainly can envision that that can take a lot of load—nice wood and joinery as well.

 

The material I used to make the 2x2s is pine, which I already regret a little. I wasn't sure if I could process rough lumber with the available tools and time, so I chose s4s lumber from a big box store. Not a great solution, I know.  I used the typical 1" (nominal) thick boards, cut them to width, and laminated them to the appropriate thickness. All pieces are laminated, straight, and free of defects.

 

Here is the joinery I consider to use for the upper corner joints. Other joints will be groove and rabbet or simple Festool dominos.

 

I thought about solid wood, which is probably the best solution, but I am unsure if I will get that perfectly flat. Hence I will try 1" baltic birch if I can get some locally. I would think that is plenty strong for that purpose. Also, it will be perfectly flat, which is important for equal weight distribution throughout the surface. 

 

The tabletop will be laminated with black Formica to be resistant against water and other stuff coming with cleaning and the like. 

 

 

[Coop]

That’s some sweet looking joinery! 

[Chestnut]

That's some complicated joinery. It should get the job done. Make sure to glue it though.

The apron stock isn't very tall so I do advise using a plywood panel where you don't have doors. 2" thick material will not offer much for support.

For the top If you are goign to frame it and cover it with melamine, you could always stack multiple sheets of BB ply glueing each layer together and nail. 1.5" was my gut recommendation for thickness for both aesthetics and strength.

[wtnhighlander]

I second the advice to glue those joints liberally. I know from experience, the outer portion of the 'hooks' will snap off in a heartbeat, if not firmly adhered into the bridle.

[Ronn W]

It appears that your aprons are acutally bearing on the legs rather than attaching to the sides of the legs - good choice for large loads

[Christoph]

Hi all, 

Thanks again for all the input. 

Here is a short update on the project. 

It went from laminated pieces of wood to cut all the joinery and finally to the glue-up. 

The glue-up happened on a very flat surface. The plate on top is pretty heavy and just ensures that nothing gets out of alignment during the glue-up. I used epoxy for the glue-up since wood glue sets too fast and may have made alignment difficult. Initially, the plan was to use WestSystem Epoxy with a filler, but my hardener pump was not functioning, so I used System Three T88. I used it liberally and had lots of squeeze out. The last picture has the side wall already in but not finally glued. They are a tight fit, still thinking if I should use only glue or glue and some pocket hole screws. 

Thanks 
Christoph 

[man of wood]

Your plans look good and will work, one of the most important things will be the panels.......  the way you Built is very strong.  Panels will keep it from racking

 

Thomas

 

[wtnhighlander]

The frame looks good! As for the panels, I see no need to use glue AND screws. Its just my opinion, but I might use screws only, on a couple of them, in case you ever need access to areas inside that are difficuly to reach through the doors. I understand large aquariums typically house the pumps & filters in the support cabinet. Easy access to the plumbing might be handy.

[Ronn W]

Nicely done.  I like it.

[Chestnut]

Looking sharp. I'm excited to see it finished with the tank on top.

[Christoph]

Hi all, 

Thanks again for all the good advice!

I would like to close the loop here and show the finished project. 

This was my first cabinet-like piece of furniture with drawers and doors and the like. 
I spray painted it white using my Fuji HVLP spray painter. Other than test runs, this was the first time I used the Fuji. 
The paint is General Finishes, three coats of primer, and three coats of  Milk Paint.  
The top is Formica laminate, glued on one inch plywood with weld-wood contact cement and finished with a hard maple edge banding. 
Unfortunately the fishtank was damaged during transport and we have to wait for the replacement.

 

Thanks 

Christoph

 

 

 

 

 

[Coop]

Very, very nice! 

[Tom King]

Looks great!

[wtnhighlander]

Nice job on the paint, too! Did you add a clear coat over the milk paint, or did it just come out that sheen from spraying?

[Christoph]

Hi all, 

Thanks for the positive comments. 

To the paint. 

I did not use a clear coat. I would have,  but after I bought the paint, I found out that a clear coat is not recommended over "snow white" because the clear coat can get some amber tone over time. Snow white is the only Milk Paint color where a clear coat should not be used. 
 

[BonPacific]

Looks fantastic!

[roughsawn]

Awesome!

[Ronn W]

NIcely done, sir. I like it.