Stand design weight check

[ilawis]

Hey everyone,

My 380 gal tank has arrived and I've built the stand but I'm a bit concerned i haven't built it strong enough so Ive been nervous about putting water in it.
So i have 7 pine uprights all 3.3 by 3.5 all sitting under a frame made of the same size wood with marine ply on top and 3 cross braces of 2x4
the tank size is 94 long 29 wide and 31 tall

The entire system is on a concrete pad (of unknown thickness) with a sand base under the slab.

Do you think i need to add more uprights or do something else with it?

 

[fishguy242]

hi,looks nice,but would like to see a few more pics of underside support

 

[ilawis]

hi,looks nice,but would like to see a few more pics of underside support

Thanks for taking a look

 

[fishguy242]

looks good!! assuming lag bolts? cannot see fastners

 

[ilawis]

looks good!! assuming lag bolts? cannot see fastners

2x4 are screwed in using 10g 65mm screws (2.5inch long screws not sure how to convert 10guage tho)
the main beams and uprights are in using a countersunk 14-10g x 75mm (3inch screw) quite a heavy duty screw but Ive had to counter sink some of them in quite a long way to ensure i have good penetration of the other wood

 

[fishguy242]

may want to angle brace 4 corners inside top rim.better safe than sorry,i'm thinking you are more than halfway through leg at this point to get into next piece

 

[ilawis]

may want to angle brace 4 corners inside top rim.better safe than sorry,i'm thinking you are more than halfway through leg at this point to get into next piece

yea the 3" ones would be about half way through tho both pieces of wood are on top of legs, albeit some by only 1/2"
ive also just rechecked (it was almost 2 months ago i built the stand) the legs are connected to the top using the 2.5" screwed in on a angel from below.

when you say angle brace 4 corners inside top rim your talking about using a steel L bracket screwed in to each corner? tho that sound like a good idea for all my connections including top onto the legs.

 

[fishguy242]

yes that would work,will eventually rust ,give me a min

 

[ilawis]

yes that would work,will eventually rust ,give me a min

so you don't think i require any more uprights with that much weight?
that black paint you can see is a liquid pond liner so i can always paint that over the paint that they will already have anyway

 

[fishguy242]

blueprint of the year..lol

 

[fishguy242]

i think with the 4x4 supports will be fine ,if worried add one more to front ,tight to other ,will make front leg 7" wide

 

[ilawis]

blueprint of the year..lol

Haha love it looks like my note book
are you saying use one of those 2 sizes? 2"x4" or 3 1/2"x1 1/2"?

 

[ilawis]

Haha love it looks like my note book
are you saying use one of those 2 sizes? 2"x4" or 3 1/2"x1 1/2"?

actually Ive just thought about it i might not need those brackets in your image Ive glued the 18mm 3/4" marine ply onto the top of those boards using "no more nails" and screwed them in using 1 1/2" screws every 6" from top down (it has given me another problem tho) the no more nails expanded and because its tight where the screws are the marine ply has now got a wave effect going and I'm worried its going to affect the glass (glass is only 12mm low iron face)
i am hoping the weight will close the gap and the polistrine (foam) will absorb this wave

 

[fishguy242]

hi, yes tank will seek true level into styro

 

[92Miata]

To echo @fishguy242 , my biggest concern looking at that is dealing with lateral/twisting motion. The uprights will hold the weight fine - what they won't survive is any sort of horizontal movement, and there's very little visible to prevent that sort of movement.

Is it screwed to that plywood wall panel? That would prevent a lot of my concern (although only in one axis)

 

[ilawis]

Sorry I've been away for a while yes it's screwed to the wall panel - not strongly screwed but it is screwed.

I've just gone and bought some galvanized brackets to go on some of the joins yesterday that I will install with coach bolts today I'll post some photos later today once they are installed and anything else i get done today.

I have put 5 inches of water in the tank yesterday just to check the bottom seals

Wouldn't any lateral twisting be prevented by the marine ply being screwed and glued down into the horizontal top frame?
My reason for being reluctant to install more wood into it is I'll have to do more waterproofing but if what I've got and doing is still not adequate I'll definitely install the braces as @fishguy242 recommended.

 

[fishguy242]

hi,HAPPY NEW YEAR!!!...still concerned about screw length ,1/2 way though material.,poss add a couple of longer lags ,bolts,to corner legs assure no twist in stand in future

 

[Mastiffsrule]

Evening all,

Fishguy is the bomb on this. So I did just want to mention rocket engineer plans also if you needed. I think you have plenty of compression strength, the way the frame sits on your stands worries me like the others mentioned. You do not really have much tying them together.

The build is looking great though. Going to come out sick. Can’t wait to see it filled

DIY Stands Template and Calculator - Reef Central Online Community

DIY Stands Template and Calculator Do It Yourself

reefcentral.com

 

[RocketEngineer]

For some reason that thread always seems to come up in these discussions. If the stand is glued to the back plywood and the top plywood, the only direction left is to pull away from the wall. However, that’s not very likely given the size of the legs. I think you should be just fine.

 

[ilawis]

This is what I've done so far this morning
Do you still recommend the wooden braces? If you do I'll get them on.
Thanks for everyone's help and happy New years!