200g in-wall project officially started

[Horace]

I would just get some marine epoxy and fill that hole in the bottome bulk head. Its possible it was used to run a spray bar or something underneith the LR. Ive seen that before. I wouldnt even bother drilling out the silicone either. just use a generous amount of epoxy over the whole thing. Personally I dont think a box is a good idea at all. The box will probably fail because you will have all that pressure pushing on a void space, much like a submarine. Epoxy is super strong stuff and if the silicone was holding up all this time, it will last forever if its covered in epoxy. That is a pretty small bulkhead too so it wont have to hold the pressure that a big one will. You will be fine....

 

[kennethl]

I'll have to agree with Horace (first time for everything) butmaybe take it a step further. Buy a threaded vinal plug and plug the hole in the bottom, then fill with marine epoxy.

I would be very careful about cutting the holes in the top out any larger. I've been ready to do the same on several occasions but the thought of compramising the structural integrity has always stopped me from doing it.

now if you were to use the tank as a sump and only fill it 1/2 full.. that might be a different story.

Use sheet rock, green wall whenever possible.. for paint, I suggest swimming pool paint..

 

[Horace]

<a href=showthread.php?s=&postid=6275428#post6275428 target=_blank>Originally posted</a> by kennethl
I'll have to agree with Horace (first time for everything) butmaybe take it a step further.

NOW NOW! What exactly is that all about?

 

[Benny Z]

thanks, kenneth, for your input on further enlarging the top openings. i pretty much have the same concern as you. a few people who have seen the tank in person suggested cutting the openings...i think your buddy horace was one of them. his concern wasn't so much tank access, but that the acrylic will block a good portion of the lighting over the tank.

what if i were to brace the top of the tank around the perimeter? i've read of people fabricating 90* steel as perimeter bracing. anyone here a welder?

what was your lighting setup over this tank again? i know you've told me, but my memory is failing me. my current plan is to use 3 400w blueish (15k?) halides (legoz can provide the specifics) and t5 for additional actenic supplementation. i sure wish those 14k pheonix bulbs were available in 400w mogul.

 

[Horace]

My issue was both the fact that your not going to be able to put big pieces of LR and the fact that it WILL block atleast 20% of the light where the acrlyic is between the light and the water. Plus how can you easily clean the under side of it?? Must be a royal PITA. I really dont think cutting a few inches out of it will make any difference at all. Your talking VERY thick acrylic there. I doubt very very highly that your going to flex the acrlyic in that direction. Your pulling against the horizontal plane of the acrlylic which will hold a tremendous amount of pressure. HOWEVER, I would leave some strips that go from front to back in all the key places just like a normal glass tank does. Look at the flimsy supports that glass tanks use. That stuff is like 1/4 of the thickness that you are using, if that. I have seen many acrlyic tanks and none of them have such small holes as you have. Most have a lip around the whole edge that is only about 3" wide. They usually have 3 large squares cut out for access and the strips between them is what gives the support for the front to back. But dont take my word for it, what do I know, right Ken?

 

[rick rottet]

I was thinking along the same lines, keeping about 2" - 3" of the top all around the perimeter (euro-brace) plus two cross braces going across the width of the tank, also maybe 2" or 3" wide. Really should be plenty.

I still don't think a box over that bulkhead would be a concern. The pressure on any part of the tank is a function of depth and area. The small area it would take to cover that bulkhead, (maybe 4 sq in using a 2" X 2" box), would only "feel" the pressure from the water that is in a column directly above it (like an elevator shaft). I don't know exactly how deep the tank is, but a 24" water column exerts roughly 0.86712 psi, multiplied by the (roughly) 4 sq in of surface area = (roughly) 3.47 pounds of pressure (total). It wouldn't have the pressure that one of the long sides of the tank would, say 6' X 2' (upwards of 700 pounds of pressure).
Having said that, I will concede that is best to err on the side of safety. A solid structure is obviously stronger than a hollow structure, and one of the reasons I suggested removing the bulkhead and covering with a flat piece. Probably would be easier (less work) to just fill it like Horace suggested.

 

[Benny Z]

does the fact that there are many holes drilled in the top near the perimeter (like RIGHT next to the side pieces) change your view on it being ok to expand the openings?

 

[Horace]

I truely think your going to be just fine. If you dont want to take our word for it, browse over RC and see if you can find some top shots of other acrylic tanks out there. Ive seen a few in person that were as large as yours and none have had the super small openings at the top like that.

If anything is going to fail on you it will be the seams breaking, it wont be because of the lack of strength of your top piece of acrylic, I can gaurentee you that.

Take a look at this tank....see what I mean

 

[Horace]

heres another one:

 

[Sloeber]

1) i would not use treated lumber. period.
2) i would not buy lumber from any national chain store (lowes, home depot, menards, etc)
3) i would not use a 4x4 as my top support. 2x6 maybe, but preferably a 2x8.
4) 8 legs? :eek1: the weight will be supported in the 4 corners. if you have to support the center of the stand, you did something wrong

that is just for starters

 

[Benny Z]

ok, i'm just curious...

regarding this informational artical, posted on this page of our very own reef central's diy how-to links page...

does "pt" NOT stand for "pressure treated"???

if it does, and if it's such a big deal that i shouldn't be using it, then why the heck is this posted here for all to reproduce? that is why i bought the pressure treated lumber.



assuming i'm not going to remake the stand, what can i do to make this work? has the suggestion of coating the stand with marine sealer not been enough? there will be nothing under the tank except possibly some storage for unused equipment, drygoods, etc.

it was my understanding that acrylic tanks have the weight evenly distributed across the bottom of the tank, not at the four corners like a glass tank. am i wrong there? regardless, since this will be a permanent fixture in the house, i wanted 8 legs. i know it's overkill.

 

[Sloeber]

<a href=showthread.php?s=&postid=6287602#post6287602 target=_blank>Originally posted</a> by Benny Z
ok, i'm just curious...

regarding this informational artical, posted on this page of our very own reef central's diy how-to links page...

does "pt" NOT stand for "pressure treated"???

if it does, and if it's such a big deal that i shouldn't be using it, then why the heck is this posted here for all to reproduce? that is why i bought the pressure treated lumber.

like any magazine or website, RC is not responsible for information posted by members. as per the user agreement -

4. CONTROL OF INFORMATION: You acknowledge that Reef Central does not control the information available on the message boards, chat rooms and other user and member-generated pages and that any opinions, advice, statements, services, offers or other information or content presented or disseminated on any bulletin board, chat room or on any other user or member-generated pages are those of their respective authors and they are solely liable for their content. Although Reef Central may from time to time monitor or review discussions, chats, postings, transmissions, message boards and other user and member-generated pages on this web site, neither Reef Central nor any of its agents, representatives or licensors is under any obligation to do so.

5. NO WARRANTY: The member-generated content of this web site contains information, facts and opinions from various individuals and organizations. They are provided on an "as is" basis without warranties of any kind, either express or implied, including but not limited to warranties of title or implied warranties of merchantability or fitness for a particular purpose, other than those warranties which are imposed by and incapable of exclusion, restriction or modification under the laws applicable to this agreement. Neither Reef Central nor its affiliates endorse or are responsible for the accuracy or reliability of any opinion, advice or statement on the service or the sites.

assuming i'm not going to remake the stand, what can i do to make this work? has the suggestion of coating the stand with marine sealer not been enough? there will be nothing under the tank except possibly some storage for unused equipment, drygoods, etc.

a) i'd be concerned the marine sealant maynot fully adhere to presure treated lumber.
b) my concern was with the warping which is outrageous on pressure treate lumber.

it was my understanding that acrylic tanks have the weight evenly distributed across the bottom of the tank, not at the four corners like a glass tank. am i wrong there?

partially. the water in the tank is displaced through the entire bottom, hence the bottom of the tank needs to be fully supported. however, the weight from the tank is supported by the stand on the 4 corners.

regardless, since this will be a permanent fixture in the house, i wanted 8 legs. i know it's overkill.

and possibly dangerous. it may seem like extra support, but it also increases the chance for error. make one of the 4 center posts 1/16" off and you will have a pressure point on the acrylic pane and 200g of water on your floor eventually. consider the pressure treated lumber will warp and shrink while it is drying, i'd say you do not have much of an option. JMHO.

 

[Benny Z]

awesome. that's a great cya disclaimer.

i think it's ridiculous that we have misinformation clearly posted as a diy how-to, but that we can't talk about a new local store's opening and shipment arivals in our own local forum. sounds to me as if there is more time spent policing would-be advertising offenses than the quality of the published content.

jmho

 

[Sloeber]

yes, you are exactly right. it is too bad it has to be like that, but such is the life of running a website as large as RC. it is a wonderful catch 22 - if members did not spend so much time violating the UA we would have more time to accomplish other objectives. if you have time to donate to RC to read everything that gets posted and ensure the 100% accuracy of it, please step up and volunteer your time. webmaster@reefcentral.com

 

[Benny Z]

i think there's a difference between what is posted in the forums and what is posted as a technical how-to tutorial on a dedicated page.

oh well. not much i can do about it. i'm clearly the last person that should be reviewing such things for technical correctness.

so, on a scale of 1-10 (1 being the lowest, 10 being the highest), how much of a risk to you honestly feel continuing on with this stand as designed actually is?

i am obviously going to have to assume some level of risk with a project as large as this.

 

[Horace]

<a href=showthread.php?s=&postid=6286550#post6286550 target=_blank>Originally posted</a> by hcs3
1) i would not use treated lumber. period.
2) i would not buy lumber from any national chain store (lowes, home depot, menards, etc)
3) i would not use a 4x4 as my top support. 2x6 maybe, but preferably a 2x8.
4) 8 legs? :eek1: the weight will be supported in the 4 corners. if you have to support the center of the stand, you did something wrong

that is just for starters

That sounded a bit harsh IMHO. Not that I am necessarly disagreeing with your statements (I really dont know much about building stands to even argue with you), but you could have atleast given him some alternatives to what he's doing. Just saying dont use PT lumber and dont buy at Lowes isnt really helping anyone here.

I do see your point about making too many legs though, I never really considered the fact that if any leg was higher that it might create a pressure point.

By chance do you have a link to a "how to" that you see as well designed for him to follow?

 

[brad23]

Ben you might have got a better responce if you had started a thread in the DIY section.

Although you will probably get people telling you what is right and wrong and that all have something different they believe works.

Take what you read from a lot of people on here with a pinch of salt.

 

[Benny Z]

thanks...

i have no problem with people stating their opinions and suggestions. that's precisely why i started this thread.

it's just frustrating to use a resource on the site to begin building the first part of the project (the stand) and then come to find out that the diy article started me down the wrong path.

i would still like to hear henry's opinion on the level of risk i'd be taking by using the stand as currently designed. i will be adding a 3/4" ply top to the stand and then two pieces of 1/2" styrofoam insulation on top of that before the tank.

 

[Benny Z]

I was thinking along the same lines, keeping about 2" - 3" of the top all around the perimeter (euro-brace) plus two cross braces going across the width of the tank, also maybe 2" or 3" wide. Really should be plenty.

i've been thinking about this a lot and have decided to leave a 5" perimeter around the top of the tank, plus two strips (probably also 5" thick) front to back in between the new three larger holes.

i'm going to mark the cut lines on the tank later this afternoon. once i do i will post some detailed pics and then get your (anyone's) input before i cut.

 

[boxer85]

<a href=showthread.php?s=&postid=6286550#post6286550 target=_blank>Originally posted</a> by hcs3
1) i would not use treated lumber. period.
2) i would not buy lumber from any national chain store (lowes, home depot, menards, etc)
3) i would not use a 4x4 as my top support. 2x6 maybe, but preferably a 2x8.
4) 8 legs? :eek1: the weight will be supported in the 4 corners. if you have to support the center of the stand, you did something wrong

that is just for starters

ok, i typed a long response, but it got lost in cyperspace.

#4 is COMPLETELY WRONG. are you a structural engineer? how can an accountant make that statement?