Need help/advice with T slots as extra support inside a wood stand

[JoJosReef]

Hi all,

I want to add a bit of extra support in this stand:

It is made of laminate skinned marine grade plywood. The two center walls are also weight bearing. The back wall doesn't seem to be weight bearing, just structural.

In any case. I'm taking an abundance of caution and want to add some additional support to this stand using three 2020 T slot rectangles.
Pretend the blue lines are straight T slot profiles.

And one in the middle wall next to the sump:

My question is, how precise do the measurements of the T slots need to be? I am assuming really precise, but what happens if it is off by a mm?

For example,

I measured the height from bottom of the interior stand plywood to the top of the interior stand at 31 and 8.5 16ths of an inch (800.89 mm). Presumably, it is meant to be 13.5" (800.1 mm). Maybe that is measurement error on my part (even likely), but what happens if I get the T slots and they are 1 mm short from being flush against the bottom and the top? What would you use for the gap? Likewise, what if it is 1 mm too tall!?

Next question:

My thoughts are to make the 3 rectangles using corner brace/angle brackets (I sometimes see them called gussets), and then I would drill a few holes in the plywood to fasten the profiles to the wood walls using hammer nuts and button screws. Does that sound reasonable?

In the end, I would like the stand's top plywood to be protected from bowing.

Happy to get any additional thoughts you might have. Thanks!!

 

[fishguy242]

If going this route ,yes just be precise on each cut ,would add couple of slots across back wall over sump to prevent racking.
I Love spending other people's money...
is that the final decision on top of stand ,plywood and a leveling mat VS the thick glass ?

 

[JoJosReef]

If going this route ,yes just be precise on each cut ,would add couple of slots across back wall over sump to prevent racking.
I Love spending other people's money...
is that the final decision on top of stand ,plywood and a leveling mat VS the thick glass ?

The thick glass to sit on top of the plywood was a great idea until I found what a 16 inch x 4 inch quarter inch thick piece of glass cost. The thick 48" x 20" piece would be way too expensive, unless I can find a place scrapping the glass.

 

[fishguy242]

You were 1st considering 5/8 correct ? have you tried any local tankmakers ?
think is overkill, but better safe than sorry ehh...
ply is not going to be cheap either, want a hardwood, the more ply count the stronger it will be.

 

[JoJosReef]

You were 1st considering 5/8 correct ? have you tried any local tankmakers ?
think is overkill, but better safe than sorry ehh...
ply is not going to be cheap either, want a hardwood, the more ply count the stronger it will be.

Agreed, and then the plywood might not look right if it wasn't skinned the same as the rest of the tank. The glass/acrylic could have a strip of accent LEDs taped to the back to shine through. Reef of the Month material, there.
Innovative marine is nearby, I could give them a call.

 

[Solo McReefer]

That looks like that CurrentUSA tank, anyway

Not an engineer or anything

But by my reckoning

Running at least 2040 across the front and back long spans seems like a good idea. Since those is the weak spots on the Red Sea Gen 1 Reefers

Also a thick sheet of HDPE across the top would add a lot of strength. Countersink some screws into the wood around the edges, would add a lot of torsional rigidity

2040 is about twice as strong, and 15% more expensive roughly as 2020. 15/30 would be better, but takes up more room

 

[JoJosReef]

That looks like that CurrentUSA tank, anyway

Not an engineer or anything

But by my reckoning

Running at least 2040 across the front and back long spans seems like a good idea. Since those is the weak spots on the Red Sea Gen 1 Reefers

Also a thick sheet of HDPE across the top would add a lot of strength. Countersink some screws into the wood around the edges, would add a lot of torsional rigidity

2040 is about twice as strong, and 15% more expensive roughly as 2020. 15/30 would be better, but takes up more room

Thanks, this is great info. Yes, it's the CurrentUSA tank. Construction looks quite solid to me and a woodworker I know, but just taking extra precautions since a disaster in my office would effectively be my exit from the hobby (at least for a long while). The Red Sea Gen 1 debacle makes me nervous, and this tank seems to be designed with similar aesthetic even though the stand is build differently. This part I just can't understand:

Why not drop the doors a half inch so you can make the plywood extend all the way to the front of the tank? ¯\_(ツ)_/¯

Will check 2040 instead of 2020.

RE: HDPE, I am speaking with someone today who has thick acrylic that I can perhaps get cut to 48"x20". Would the proper thing to do be A) lay it on top of the stand (maybe with a leveling pad so it doesn't slide) with the tank/leveling pad on top of the acrylic?; or B) drill 4 holes in the corner of the acrylic and screw the acrylic into the plywood top of the stand? I'd have to figure out how to make the holes so that a screw gets sunk under the plane of the acrylic so it remains completely flat on the top. I'm sure someone has a tool for that.

RE: long spans, I can only get a 2040 profile across the front since the back has the two walls in the middle blocking a profile crossing the back. I don't want to cut out any part of that, which is why I was thinking the left, middle and right rectangle profiles would help with preventing any bowing. I can still add the lateral profile at the top front. Would you drill into the top plywood to attach it to the top or just use the other T slot profiles?

Thanks!

 

[ScottD]

RE: HDPE, I am speaking with someone today who has thick acrylic that I can perhaps get cut to 48"x20". Would the proper thing to do be A) lay it on top of the stand (maybe with a leveling pad so it doesn't slide) with the tank/leveling pad on top of the acrylic?; or B) drill 4 holes in the corner of the acrylic and screw the acrylic into the plywood top of the stand? I'd have to figure out how to make the holes so that a screw gets sunk under the plane of the acrylic so it remains completely flat on the top. I'm sure someone has a tool for that.

I would go with option B in my opinion. You could either get a countersink drill bit to do that or do it in stages with 2 drill bits. First drill a hole all the way through with a drill bit slightly bigger than the threads of the screw you’re using. Next find a drill bit that is as big or slightly bigger than the head of the screw and drill in just deep enough for the head of the screw to be below the surface. I would then take either super glue or some 5 min epoxy and fill in the heads after it’s mounted to the stand so that water can’t puddle in the holes.

 

[Slocke]

I am an engineer.

I haven't got anything to add. I just wanted to brag.

 

[SliceGolfer]

@JoJosReef - Option C: Build a new stand from t-slot, skin it with the boards from the existing stand

 

[Slocke]

So, in all seriousness, your most significant issue is not the vertical forces but the horizontal forces, as we discussed in your build thread. I would look more at thinking about putting a bottom rim on the tank. See my ProStar tank:

This both reduces the strain on the silicone seams of the tank but also transfers the downward force onto the edges of the tank and into the strongest parts of the stand.

 

[Dom]

Wow... that is the stand design out of the box? I wonder why (as have others) they wouldn't extent the stand to cover that extra 1/2 inch?

 

[Solo McReefer]

Thanks, this is great info. Yes, it's the CurrentUSA tank. Construction looks quite solid to me and a woodworker I know, but just taking extra precautions since a disaster in

A disaster anywhere

Anyway

It's what I am doing. Just need to start cutting aluminum

 

[Slocke]

Wow... that is the stand design out of the box? I wonder why (as have others) they wouldn't extent the stand to cover that extra 1/2 inch?

Oh gosh. That stops my idea of adding a bottom rim.

 

[JoJosReef]

Oh gosh. That stops my idea of adding a bottom rim.

Was thinking of doing an inside-bottom eurobrace. I've just never done it before, so hesitant to mess this thing up.

 

[Solo McReefer]

they wouldn't extent the stand to cover that extra 1/2 inch?

It is so the tank doors close flush with the tank glass

It was an Elos design originally, Red Sea copied it(to their detriment)

Seems CurrentUSA has used it as well

 

[JoJosReef]

It is so the tank doors close flush with the tank glass

It was an Elos design originally, Red Sea copied it(to their detriment)

Seems CurrentUSA has used it as well

It does look nice, but I'd rather have the peace of mind of a stand that is more structurally sound. I don't know how big of an issue it really is. I will just work on some internal supports and if the large piece of acrylic works out, that will be a nice "pedestal" for the tank covering the entire bottom--I can also add some accent lights shining through the acrylic from the back

 

[Slocke]

Mine has the same thing but the rim of the eurobrace is made extra wide it appears

 

[Dom]

Oh gosh. That stops my idea of adding a bottom rim.

With that design, the entire front pane of glass is relying solely on the silicon.

I see the weight of the pane over time putting strain on the silicon. Add to that the water pressure against the front glass.

I don't know about this. I'd probably build a new stand and use this stand to "skin" the frame of the stand I build.

 

[Dom]

It is so the tank doors close flush with the tank glass

It was an Elos design originally, Red Sea copied it(to their detriment)

Seems CurrentUSA has used it as well

I didn't realize that Current USA made their own tanks. I just came from their website and to my surprise, there is a blue banner on top that says "All customer service and support is now handled by saltwateraquarium.com

Was Current purchased by saltwateraquarium.com?