stand flatness opinion, 11.5 foot stand

[sarens]

-doing a 11.5 foot long x 24" wide stand for the tank

-how flat do you think it needs to be?

-putting (2) 3/4" plywood with 1" foam on top

thanks,

 

[Dmorty217]

Glass or acrylic? As plumb as you can get the stand to be with the floor it will be setting on

 

[sarens]

will be acrylic, I can get the tank stand level but the stand itself shows a .06" dip in the center, tapering toward each end

 

[sarens]

would be very difficult to straigthen the stand, it is fully welded and painted and is VERY strong and rigid will have foam on top and really wondering if the foam will compress to create a flat surface

 

[ca1ore]

Since you are adding the 1 1/2" of ply, can you not shim it?

 

[sarens]

Since you are adding the 1 1/2" of ply, can you not shim it?

thought about that but then worried about point contact on the shim/plywood

-would basically need a shim that tapers 0.06" over a 69" length to keep solid contact

 

[Dmorty217]

who built the stand and tank? I would ask them this question before risking it if it were me

 

[reefwiser]

A rimless tank has to have a very level surface with padding underneath or the tank will crack. Here is what happened to a club members tank.

 

[ca1ore]

thought about that but then worried about point contact on the shim/plywood

-would basically need a shim that tapers 0.06" over a 69" length to keep solid contact

Well, you could shim between the stand and plywood every six inches - you wouldn't have to do it along the full length. We're not talking very much, though; only slightly more than1/20thbof a inch. Agree that you should just ask the tank maker.

 

[sarens]

who built the stand and tank? I would ask them this question before risking it if it were me

- i built the stand, tank manufacture says it is flat enough I just wanted some of your expert opinions

 

[sarens]

A rimless tank has to have a very level surface with padding underneath or the tank will crack. Here is what happened to a club members tank.

View attachment 310803

that is exactly what I am scared of

 

[sarens]

Well, you could shim between the stand and plywood every six inches - you wouldn't have to do it along the full length. We're not talking very much, though; only slightly more than1/20thbof a inch. Agree that you should just ask the tank maker.

he said I will be fine, just scares me, I did a test today with the foam and simulated the psi of the tank, didn't see much compression of the foam so I'm spooked

 

[Dmorty217]

I can understand your fear... That's a lot of tank to have something happen

 

[CuzzA]

My steel stand had 1/16" hump from the center cross bar. I just planed out a 1/16" of the bottom of the plywood and now it sits flat. My point is it will be much easier to manipulate the wood than the steel. Also, perhaps you could just inject epoxy into the gap. Maybe clamp some wood to the side with some max paper to keep the epoxy from flowing out and for easy removal of the fence.

 

[sarens]

My steel stand had 1/16" hump from the center cross bar. I just planed out a 1/16" of the bottom of the plywood and now it sits flat. My point is it will be much easier to manipulate the wood than the steel. Also, perhaps you could just inject epoxy into the gap. Maybe clamp some wood to the side with some max paper to keep the epoxy from flowing out and for easy removal of the fence.

I like that idea, will try that