Leveling a stand - concrete,styrofoam,pond liner?

[aroundtuit]

I need some advice from those of you who have built your own stands. I've built a 110 in-wall (glass). One corner was slightly low, so I shimmed up the stand and got it perfectly level. Everything looked great.

Then I noticed a paper thin slit of light between the back and the plywood top on the stand when I turned the light on. You had to look at edge on to see it. It went nearly all the way from one corner to the other. Without the light, it was not visible. Perhaps I was just being to concerned, but this worried me.

Somewhere on here I got the idea of a self-leveling liquid to make it perfectly flat. So, I got some self-leveling concrete at Lowe's, made a small lip around the edge of the stand and poured a thin layer (less than 1/8"). Now it looks worse. The edge is not consistent and I'm concerned about it chipping. It doesn't appear that the concrete will come off so I can't go back. If I had thought of it in the beginning, I would have made the stand an inch wider on all sides.

Is it normal/okay for there to be a thin slit of light? Should I have used something other than concrete? Would Styrofoam solve it now? I've also thought of getting one of those rubber liners they use to line ponds. That would water proof it, level out the small bumps and be easily removed.

Any suggestions/ideas are welcome.

Thanks.

Edit: I was planning on drilling the back of the tank this weekend.

 

[MayoBoy]

If it were me, I'd take off the old top and put a new piece of plywood on. Then I'd use some foam insulation or a piece of cardboard to compensate for any unevenness in the ply.
I'm not a big fan of leveling compound, especially over a material like plywood that's going to get wet.

If it cracks or moves and the tank settles and cracks, you could be out a lot of money. Plywood's cheap...

 

[aroundtuit]

Unfortunately, I glued, screwed, and nailed the top on. I may not be able to get it off. And if I put another sheet on top of I'll have to redo the whole wall that I just finished!

Do you think the pond liner would work?

 

[MayoBoy]

It should depending upon how uneven everything is. Have you put a 4 or 6 foot level on it to see how bad the gaps are? Remember, it has to be good along the entire perimeter to support the tank.

 

[aroundtuit]

I'm only looking at the perimeter and with a 4 ft level. Over all its right on level. The gap is < 1/16". I think part of it is because the surface is not real smooth near the edge. It's a little bumpy because of the grit in the concrete. It may be that I did not mix it wet enough.

 

[MayoBoy]

I'd probably go with a big piece of cardboard. It will compress enough to absorb any differences.

 

[Letmegrow]

Styro.

 

[Letmegrow]

I've got some too, PM me.

 

[aroundtuit]

LetMeGrow -

Is that just the Styrofoam insulation like HD and Lowe's sell in 4x8 sheets for insulation? I think I have a 1/2 in piece already. Although its probably not 18.5 x 60.5. But since I only need to cover the perimeter, I can probably cut it to strips that will cover that portion.

The hard thing will be to slide it into place. It's in a nook. The front is built into the wall of course, and one end is also against a wall. And there's only about 30 inches of open space behind the tank. Guess I could set it up on dowels or something to get everything in place.

MayoBoy - Would that be corrugated cardboard? I've got a couple sheets of that I know.

 

[Letmegrow]

It's pink and super thin, and folds out into sheets. It's what everyone uses to level tanks. You could try and stuff it in there, hind sight is 20/20.....

I can not gather if the tank has water in it yet or not.
If it doesn't then get some people to lift it and do it, if it's got water in it, just leave it alone.

 

[aroundtuit]

Okay, I think I've seen the stuff your talking about.

BTW, the tank is empty as I wanted to drill it this weekend. My plan was to get it setting level, fill it and mark the water line, drain it, drill it, and put in a horizontal overflow all the way across the back (hence the waterline mark).

 

[MayoBoy]

Regular corrugated cardboard - that's what I have underneath mine. Use a full sheet the same size as your stand - see if Lowes or Home Depot has an old refrigerator box left over or something. Don't try and piece it together or you might get a stress point.

 

[Letmegrow]

Yeah, then just get the pink stuff and set it on it.
You got the right idea.

 

[aroundtuit]

Well, I had a 4 x 8 sheet of corrugated cardboard, so I cut a slightly over sized piece from it, . I figured I could trim it down later. The thin sliver of light is gone! Yippee! I feel much better now.

When I'm done drilling and have the horizontal overflow in place, I think I'll put trim around the back edges to help protect against chips in the concrete.

Thanks for all your help guys!