Need more bracing on stand?

[jmp998]

I've just bought a stand and canopy for a custom acrylic 180 gallon tank (48"x36"x24"tall). The stand builder has an excellent reputation, has built over 100 stands (many for similar sized aquaria), and the craftmanship seems good.

My concern is that the top of the stand consists solely of a piece of 1" oak plywood with no cross braces. All four edges of the plywood rest on the outer frame, and are connected to the outer frame by wood screws. The stand feels very solid.

This is my first acrylic tank, and my concern is just that the center of the stand may sag/bow, stressing the acrylic. So do I need to add some cross braces under the top of the stand, or will the plywood alone be OK?

Thanks.

[FINFISH]

36" wide with no braces? Seems weak to me. 1"ply is super-strong, but I prefer to go with thinner ply and multiple braces.

[Alphabet]

Did your stand builder offer any warrenty? If he has built so many stands why don't you trust him??

It seems to me that 1" ply on top, screwed to the outer frame should be sufficient.

btw :what is the size of the wood that was used to make the frame?

[jmp998]

I worry because my tank is a little different:
1) Acrylic tanks are not popular in Dallas (probably in part because there are two large glass-only tank builders locally)-so most of the other stands have been used with glass tanks, which are supported only around the edges with no weight on the center.
2) My tank is a custom shape-3'x4' footprint rather than the typical 6'x2' footprint-so there is greater distance from the frame than for most tanks.

The frame is made of 1" oak plywood also-double thickness in stress areas.

The builder assured me the stand was very strong-I'm unsure about formal warranty, as the stand was made by a private individual not a company, doubt I could enforce any warranty anyway.

[johnpoole]

if your in doubt, add bracing, or at least another one inch of hardwood ply. a simple x brace glued and screwed under the ply would make me sleep better.. 90 percent chance you could use it forever without a problem. also a 90 percent chance you'll loose sleep thinking ablut that ten percent chance of a problem. i built my 1st stand for my 55, 30 years ago, using 4 by 4 and 4 by 6 oak. it was solid and weighed almost as much as the tank... overkill, but i didn't loose sleep.. today 2 by 4, with 3/4 ply holds my 180...solid enough

[reefkeeper59]

I'd add the brace. Easier than cleaning up 180 gal water.

[jmp998]

I think I'll add some peace of mind in the form of two 2x4's running the length of the stand-that way the span is only 18" instead of 36". Sound OK?

[FINFISH]

You'll have better strength if you go the other way (36" vs 48"), if you screw both on the end, and more importantly- the top, you should be fine. If you have the tools- you could make a "pocket" for the 2x4 ends out of plywood- then just screw the ends and not the top.

[TANGBOY5000]

Flip it up and add 2 2x4s underneath the plywood so that it looks more like a ladder frame. Even though your stand is rock solid for a glass tank, it wasn't built with an acrylic tank in mind. If you leave it as is the middle of the bottom of your tank will sag over time. Will this lead to a catastrophic failure, probably not, but why risk it. Anytime undue stress is placed on a tank that is not a good thing.

[Osler@thesea]

The stand should be fine. That is exactly what I did for the tank that I built. It is 48" x 30" x 24".....very close to your dimensions. You could add the cross-brace in the center, but I doubt you are going to end up with any sagging with 1" ply sheathing the top.

Tank and stand below:



Edit: sorry about the super-size picture.

[FINFISH]

How is that tank constructed? What did you use for a finish (looks stippled)?

[Osler@thesea]

It is acrylic encased in plywood. Front pane and bottom is 1/2" clear acrylic (delv, bottom is actually 1/2"...), sides, back, and top ring are 1/4" smoked acrylic.

Basically, I built an open top acrylic box using the above materials to the dimensions noted. Next, I encased this box in 3/4" birch plywood on the two sides and back, added the picture frame to the front for structure and looks, then put a piece of 3/4" ply on the bottom and routed to size. I then added a piece of smoked acrylic to the top using gorilla glue. With the top in place and the paper masking left on the exterior of the front glass, I proceeded to prime and paint the wood (wood was pretreated with a sealant prior to construction). After the paint dried, I routed the top open, removed all the paper masking, and added the center brace.

The tank is painted in a textured finish....yes, it is somewhat stippled. Stand was painted in a coordinating color after the dictates of the boss (a.k.a, my wife).

Tank has been up in my living room for nearly 2 years now. No problems whatsoever. It is stocked with ~180 lbs of liverock plus critters.

The stand was constructed from 2x4's that I trimmed down a bit. Vertical members are in the corners only. Horizontal members are connected to the vertical via moritse and tenon joinery. There is no center support in the stand. Stand was sheathed in 3/4" plywood and painted. If I take tank off the stand, the top of the stand is completely open. It is only the 3/4" plywood and 1/2" acrylic on the bottom of the tank that interface with the horizontal members spanning from corner to corner.

HTH,

[FINFISH]

In the picture I see a spray can in the corner- that looks like the source of your finish? I've use a similar stippled product (in spray cans), but was looking for a way to do it with a air-compressor type sprayer. I've seen it done where it even has the texture of rough rock- but I've never been able to duplicate it realistically.

[Osler@thesea]

Yep....paint is from a spray can. I, too, looked for this stuff in bulk to use with my Critter Spray Gun but couldn't locate any. There was a guy here in town that used to put a similar product on with an HVLP sprayer.....however, he has since gone out of business and I dunno how to get into contact with him anymore.