Tank Stand Design - Woodworks requested!

[Piscine]

If you extend the measurement I marked in red past the midpoint of the aquarium, the cantilever doesn't bear the load of the aquarium. It only serves to keep it from tipping forward if it is disturbed. The section that overhangs could be removed and the aquarium would still be supported. It wouldn't be very stable, but that is what the cantilever is for. The cantilever never has to bear anywhere near the full load of the 400lb aquarium, so there is no need to worry about the load bearing capacity of it. Also, good plywood is stronger than dimensional lumber when the similar thicknesses are used. It would be much more pleasing to the eye and much more compact to just sandwich two sheets of ply together in the blue area and cover with some nice trim.

Good luck! Make sure to post pictures when you are finished.

 

[skjl47]

If you extend the measurement I marked in red past the midpoint of the aquarium, the cantilever doesn't bear the load of the aquarium. It only serves to keep it from tipping forward if it is disturbed. .

Hello; This idea will be helpful. This will put the natural center of gravity of the tank at the tipping point of the stand and the extended leg should prevent actual tipping. I did not take the time to express it well in my previous post, but yes only half of the tanks weight will on the cantilever arms.

One additional thought. To move the center of gravity more to the back of the stand, more weight (gravel) can be placed in the back of the tank and less in the front. I have modified tanks to be tiered with glass panels siliconed inside. This enabled me to have 4 to 5 inches of gravel in the back and only an inch or so in the front. I have some digital pictures of one of these setups on my computer and can try to post them if you are interested.

I also agree that modern plywoods are stronger than dimensional lumber. I was thinking along the lines of additional bracing for a bit more security.

On a side note; How were the red lines added to the OP's image? This would be a neat thing to know. I had thought of a sketch to illustrate my idea, but do not know how to do this on a computer.

 

[Piscine]

Hello; This idea will be helpful. This will put the natural center of gravity of the tank at the tipping point of the stand and the extended leg should prevent actual tipping. I did not take the time to express it well in my previous post, but yes only half of the tanks weight will on the cantilever arms.

One additional thought. To move the center of gravity more to the back of the stand, more weight (gravel) can be placed in the back of the tank and less in the front. I have modified tanks to be tiered with glass panels siliconed inside. This enabled me to have 4 to 5 inches of gravel in the back and only an inch or so in the front. I have some digital pictures of one of these setups on my computer and can try to post them if you are interested.

There's no need to move the center of gravity as you are suggesting. The difference in density of gravel/rocks vs water is not enough to make a difference in load bearing design and would have a minimal effect on the center of gravity. It is a neat idea but not necessary. Simplicity is good when you are building things that are not familiar.

I also agree that modern plywoods are stronger than dimensional lumber. I was thinking along the lines of additional bracing for a bit more security.

On a side note; How were the red lines added to the OP's image? This would be a neat thing to know. I had thought of a sketch to illustrate my idea, but do not know how to do this on a computer.
I copied the image, then modified it using paint...

Reply in red

 

[Cablemonkey]

All good information, I see what everyone is saying and I was planning on having an internal structure made of 2x4 that is glued n screwed to the cabinet, utilizing both the strength of the 3/4" plywood as well as the 2x4s. I failed to put a dimension for the recess of the sides, the exposed area will only be about 6", the solid will be about 14" as was suggested. There would be a 2x4 framed and cross membered "shelf" for the top tank as well as a more traditional 2x4 stand for the bottom tank giving it a lot of strength. There will also be 2x4 support between the bottom tank and top tank using both the glued n screwed as well as flanges for added strength. I am having issues with making the skeletal drawing, if I can get it to look right I will post it also.

 

[Cablemonkey]

As far as balance issues, I dont think they will be major but the wife has already requested a safety tether be installed at the top, I was going to put a brace across two wall studs and attach it to the top back of the cabinet either eye hooks or some other type of non-permanent latch just for peace of mind.

 

[Cablemonkey]

If you extend the measurement I marked in red past the midpoint of the aquarium, the cantilever doesn't bear the load of the aquarium. It only serves to keep it from tipping forward if it is disturbed. The section that overhangs could be removed and the aquarium would still be supported. It wouldn't be very stable, but that is what the cantilever is for. The cantilever never has to bear anywhere near the full load of the 400lb aquarium, so there is no need to worry about the load bearing capacity of it. Also, good plywood is stronger than dimensional lumber when the similar thicknesses are used. It would be much more pleasing to the eye and much more compact to just sandwich two sheets of ply together in the blue area and cover with some nice trim.

Good luck! Make sure to post pictures when you are finished.

Exactly, there will only be ~27-30% of the tank sitting on the cantilever ( < new word learned!), ~70-73% will be inside the cabinet on full supports. I almost deleted the recess' but I think with the side bracing I intend to do I shouldn't have too much issue. I will definitely keep everything everyone has said in here in mind while tweaking the design. There is only about 2" space between the tanks and the back of the cabinet, I have to run the plumbing somewhere!

 

[Cablemonkey]

I was also intending to, since I dont have a biscuit cutter, drill and peg using 3/8" x 1" pegs between screws for the cabinet, maybe for attaching the frame to the cabinet as well though I am not sure on that yet.

 

[Cablemonkey]

I do have one more question, when it comes to finishing the wood, what would be the best solution to prevent swelling, softening, mold and etc due to evaporation or the like? I was thinking like Thompson's deck sealer and stain unless there is a better solution.

 

[Oughtsix]

Definitely not Thompson's! It is useless on decks and won't do anything for your stand. A good quality water based polyurethane is your best bet. Cut the first coat of poly 50/50 with water to thin it and the wood will soak it up much better giving you better protection. 4 or so coats should do the job nicely. For a prettier finish sand the 3rd coat after it has dried with 400 grit paper on a hard sanding block before applying the 4th coat. This will level out the surface and flatten out any runs from the previous coats.


I would take a slightly different approach to construction. Don't plan on the plywood you are using being the finished wood. Instead screw through the plywood with glue to make the carcase very secure then skin it with what ever finished wood you want. Contact cement works very well for this. When you apply the veneer make all the pieces oversized and then cut them down to the carcase dimensions with a router and a flush trim bit. Then finish the exposed plywood ends with solid wood pieces.

My local surplus wood dealer carries door skins that are perfect for skinning and very inexpensive. I like maple but my local guy also carries oak door skins.


I would make the shelf surfaces out of Formica applied with contact cement as mentioned above and trimmed with a router as mentioned above. The Formica will be a much nicer surface for slopping up spills than wood.

If you can score some Corian or other solid surface material for the shelves this would be even better. You can work Corian very well with woodworking tools. I would route a drip grove in the top of the Corian around the outside of the tank perimeter. Good luck finding it as most solid surface manufactures will only sell to "Authorized Dealers".

 

[suds1421]

I am a woodworker and I would not build that stand design. I think it could be done, but remember that tanks don't flex. If the front bows down the tank will crack and you will have a mad wife.

You are talking about hundreds of pounds of weight. There's no doubt that wood can support it, but support tables are built on acceptable deflection. The acceptable deflection when building a tank stand is near zero...

I LOVE the design, if I was making it I would had 8/4 square posts to the front corners. These "should" provide more support so that you don't have issues.