Plywood top of stand how thick should it be?

[QUOT E=ingtar_shinowa;1548669]Definitely put in some cross braces throughout the frame (id use 3). For the plywood, I would use 1/2 inch marine grade if you have it just because i like to overbuild a bit (3/4 is ok too). Contact your manufacturer to see what they recommend about the foam. I know some companies require it for warranty, and some it voids.

Rimless are scary that way.[/QUOTE]
I have 2 cross braces across top and bottom,
Do you recommend sides too?
I only have 1/4" ply

not su on manufacturer it was ex-display

 

What is luan?

 

I just used the 1/8" oak plywood with glue and clamps and that prevents and instability from the sides.

 

I have more or less finished the basic frame and skinning, but i may well add more braceing, where would be the best place?

 

Upon standing my new made fish tank stand in another room the thing starts to wobble, from left bottom corner to right top corner, but if i turn it round or put it in a different place in the living room its very still, i positioned a large piece of flat mdf on the floor and using a spirit level and a piece of straight hard wood i braced it across the mdf in various positions with a spirit level on top, every reading was bang on inbetween the lines, so then i placed the stand upon the mdf, no wobble at all, but when doing the same to the top of the stand some measurements are a mm or 2 out when getting the bubble bang in the middle but not over the lines,

What could be the problem and besides starting over is there a easy fix
Thanks

 

I thought I had responded, but must have forgot to hit the send button. If you haven't added anything since the last pics, you need to have some form of shear support - longitudinal is the most important, but front-back is important too. Most stands use the thin wood that hides the area under the tank to provide this. Either diagonal bracing or plywood will accomplish this.

 

I'd use 3/4" since the ends of the tank are not supported by the frame and maybe make sure a cross brace is at directly under both ends of the tank.

 

Today I will visit the wood yard and pick up some 3/4" plywood then fix it to the frame using 2 1/2" screws, coupled with more support bracing as suggested
will add pics soon
Damn this things gonna weigh a ton

 

Quick update,

I stripped the stand right down due to a serious wobble and found the the bottom frame was warped, after realigning it putting it back together it is now dead flat and rocks on no surface.

Yesterday i drove out to a local wood yard and got me some quality 18mm plywood and had them cut it to size



I used the old cutting as a template and cut the corners out for the bottom with a jigsaw



Then i pilot drill the holes and used 2 1/2" gold screws to attach the bottom and top, sinking the screws in too,



Picked my new sump up also, i love it even room for a refugium



Soon be complete, very sturdy now, but very heavy also lol, i used waterproof wood glue on the legs screw strips only, i like the idea of being able to unscrew and dismantle it if i ever need to and so have decided not to use wood filler over the screws,

 

It's looking really good!!