Need wood stand engineering consult

[Mbelanger]

Alright so I have another thread somewhere below about making an enclosed stand which the building process has been really smooth until this morning. I went ahead slid the top part of the stand on to place the tank on top so that I could mark off my drain and return holes...
Well I realized that in the process of making a slightly larger stand "to give me more play room below I did not account for where the edges of the tank would go. Now if i can set it up so the front and sides are on the 2x4 frame but then the back edge is on the 1/4" plywood w no bracing under.
How can I remedy this? I was already planning on adding a center cross brace to support the middle of the tank but haven't done that yet to leave myself room to work.
Now am I screwed and have to break down the stand and shorten to fit or is there a fix? Like thicker plywood for the top and added crosses to spread the weight??

 

[Mbelanger]

Here are the pics to help with my explanation...

 

[Mbelanger]

And 2 more

 

[davocean]

Well I'm not an engineer but I am a contractor/carpenter.
Obviously it's going to be a compromise at this point, but looking at your last pic, if you can, pull those vertical supports out, sister or double up that back horizontal at full span, and run vertical supports underneath that.
That's what it looks like can be done from what I can see in pics, and that is if you did not glue everything up as I would have done.
It's going to be bulky inside, but that is where you are at now.
If it's a trimless tank still add joist type bracing in the center, and w/ all this correction stuff I'd be sure to do a ply sub top too, tie it all together as best as possible.

 

[Mbelanger]

What do you mean by "sister". Nothing is glued. The floor part has been caulk but that's it. I'm gonna see what I can do from what you said or I'm actually considering breaking down the top and bottom and just cutting those support to shorten it.. Either way I guess lesson learned and it's gonna be a bit of pain either route
... And yes the tank is rimless

 

[davocean]

Sistering is basically just attaching another 2x
In your case it will be to bring that rim inwards so it lands where you want, but it will need support vertically under that rim that lands where glass sits.
You should always glue board members, but I guessed you may not have, as many DIY guys don't, not knowing the true strength you gain from glue(Glue is actually stronger than nails)
But if you want or need clean inside, yeah, break apart and do over.

 

[Mbelanger]

True, I guess I wouldn't expect glue to make a big difference. Figure 2 1/2" wood screw would be enough. What kind of glue would you use? Just plain old Elmer's wood glue?

 

[davocean]

I personally use tightbond III
It is water resistant.
If you glue properly, you could actually remove all screws/nails, try to tear that seam apart and you will tear wood before breaking seam.
In high end cabinet shops many use nothing but glue and clamps.

 

[saybng]

I agree with Davocean with your stand issue and I also use titebond glue..it will be your strongest bond...we use it all the time in our shop.

 

[Mbelanger]

Alright, so I'm still looking for ways to make it all work without having to do a full rebuild, so please bear with me and let me say ahead of time that I appreciate your inputs!
So just to double check, even if I put in two cross support as pictured below it prob wouldn't be enough since the entire edge would be better supported, correct?
So my easiest fix would be a full 2x4 to fit longways for the back edge, with vertical support and crosses?? The second picture is just to give an idea of what I'm trying to explain...

 

[davocean]

Yes, full board from side to side, w/ a vert support at each end.
Sorry for late reply, my city here is on fire at this time.
I just bagged up my clowns and nem in case I need to evacuate.
kinda looking ok for ME at this moment, as long as wind does not shift...

 

[M_Jaco]

I'm an engineer and I would be more than happy to help you here... BUT I'm having trouble understanding exactly what your situation is. You say the "front and sides are on the 2x4 frame"... assuming the full length of the sides are over the 2x4 frame you'd be OK. On a glass tank with a plastic rim, only the 4 corners need to be supported.

This does beg the question though... how is the 2x4 "frame" is supported. If it is simply nailed or screwed to a vertical member, thats a big no-no and the stand will fail. However, if the frame has vertical supports directly below it, you're OK.


The pictures aren't very clear to me. If you could post a photo or two from farther back(So the whole tank/stand can be seen) as well as some more pictures of the inside of the stand (so I can see how the horizontal members are attached to the vertical) I would be able to give you a better answer/solution




EDIT: after looking at the pics a little more I think I see what is going on. I'd still like to see a few more pics, but what davocean said seems to be correct. no matter what you do, you can't have any horizontal members held up only by nails/screws. they absolutely HAVE to be held up by a vertical member that bears on the ground.

 

[john08007]

I am also having a problem trying to see what the problem is, but I can suggest something that may help. I think the issue deals with attaching another 2x4 down the middle to support the top. You may want to look at the simpson section of any home depot or lowes. They are all of the galvanized metal parts used when framing a home, I think you may be able to get a 2x4 joist hanger which will allow you to add another support from the inside. Just my .02 maybe it will help if the problem is what I think it may be.

 

[davocean]

The issue from what I can tell seems he oversized the rim joist, so the tank lands inside the 2x4 frame rather than directly on top.
if he pulls it forward front and sides land right, back is floating.
basically I'm telling him bump the back forward by adding another 2x, and make sure to have vert supports under that.
It will just be bulky in the back.

 

[john08007]

Gotcha, I would then just add a few more 2x4's running across, just re-read the first post and I think the top is 1/4" wood, may wanna use 1/2-3/4 on the top also.

 

[Mbelanger]

Thank you everyone.. Here is a slightly better picture of how the stand is made. I do have vertical support not just screws holding it all up.
Following what Dave said I think I have a decent fix but I don't have any picture. I'll get back to it tomorrow cause I work for the fire department so I won't be home to work on my little project for 24hours..
And ya I have a buddy that told me to get a thicker plywood for the top

 

[davocean]

Thank you everyone.. Here is a slightly better picture of how the stand is made. I do have vertical support not just screws holding it all up.
Following what Dave said I think I have a decent fix but I don't have any picture. I'll get back to it tomorrow cause I work for the fire department so I won't be home to work on my little project for 24hours..
And ya I have a buddy that told me to get a thicker plywood for the top

Not sure what area you are in but I have to say we are in great appreciation of firefighters right now!
I almost had to evacuate yesterday, came pretty darn close.

 

[Mbelanger]

Not close to you. Accross the country in Florida. I'm in the Orlando area.
I was offered to test get "red carded" which is for wildfires and you can get dispatch anywhere but opted out. Our wildfires down here are mostly grass and some small trees but it's all flat land.. You guys have canyons and giants trees and that's just way too many scary unpredictable variables that I don't need to expose myself to.
Hope your boys out there can get a handle on things.

 

[Greysoul]

looking at it, that's not a very big stand is it? how big of a tank are we talking about?

It looks like it's not going to have more than a 40g tank on it? Throw some 3/4" marine ply on the top and you should be fine...

If it's any bigger than that, I'd just brace it along the point of contact for the back of the tank, insert legs in the appropriate place, and go with it....

 

[Mbelanger]

Naw it's 38"x24" for a 57 gallon rimless.