tank rim not flush with stand?

[seecrabrun]

The plastic bottom of my tank doesn't make contact on all sides with my DIY stand. What should I do? I was so very careful and yet the whole thing still turned out bad

Should I try to sand out whatever bumps are there making it uneven? I feel like if I do that I'll just end up making it uneven by oversanding by accident.

Should I put a high density foam? Or Styrofoam?

Should I sand it some and then put a solid wood top?

Please help! I've ended up spending a good $300 on this project already and so I can't afford to scrap it. (I ended up having to buy a couple power tools because it became obvious I physically couldn't do it all manually)

 

[lmforbis]

I always use 3/4 ply on the top of my stand. I think that will flex to the shape of the frame though. Can you post some pics.

 

[lmforbis]

This is what the structure of mine looked like. I have 3/4 plywood on top that overhangs the frame by an inch. I skinned the whole thing in 3/4 ply which made the top perfectly straight. I did have to shim the stand once it was in place because the floor wasn't perfectly level. I also lagged the stand into the studs in the wall behind it.
Finished it looks like this.

I think if you used 2X lumber to build it and the lumber is bowed upward causing the tank to be off on the ends, the weight of the tank will force it to straighten out. Otherwise You should be able to sand it with a belt sander. Not sure about the foam. It probably depends on how far out it is.

 

[silverado61]

If it doesn't sit flush in certain scattered spots then 1/4" or 1/8" foam should work for a base depending on the size of the gaps. If the tank rocks back and forth, check the level of the stand.
I wouldn't use a belt sander unless you've used one before and are comfortable with it. It could sand too much off in no time and you would just make matters worse.

 

[seecrabrun]

I think my side pieces are slightly higher than the front

 

[lmforbis]

It looks worse in the center and right side. The right side may be a bit high, you could trim the leg pieces a bit it might help If the 2x4 in front is bowed, the gap seems to be the worst in the center, you can flip the board 180 degrees so the crown is upward. This would put the bow where the tank weight will straighten it.

 

[flower]

I am not a builder, but a gap right in the center...no way, sand that thing till it's even. Considering all the weight in a saltwater tank, and the whole thing is held together with silicone on the edges. I would no way trust that stand.

 

[silverado61]

A difference that small, take the 2x4 off and flip it over like Imforbis said. Then check and see if the weight of the tank doesn't level it out. Let the empty weight of the tank do its thing for a few days. If not, now all you have to do is sand one middle, not two sides. Cuts the work in half.

 

[seecrabrun]

Thanks. I've bought a 3/4" plywood top as well.

 

[pegasus]

I had the same situation when I built the stand for my 40B. I used the straightest 2x4's I could find, and it still had gaps in spots. I finally realized it wasn't the stand... it was the plastic frame around the bottom of the tank. I ended up using Styrofoam strips. It works great, fills the gaps, provides sound deadener, and self-levels the tank. It's a win-win situation.