Secrets on seating bulkheads????

[teesquare]

yep........
T

 

[Matt_Wandell]

<a href=showthread.php?s=&postid=15027940#post15027940 target=_blank>Originally posted</a> by jlinzmaier
How so???? Many tanks are built in such a way without trouble. Explain further, I'd like to hear your input.

Jeremy

Maybe it's just a difference in philosophy; it seems to me that it gives you 10 possible leaking points that would be a serious pain in the butt to correct once your tank is stocked and filled with animals.

I'm no glass engineer but I've read more than enough stories on here of people's tanks failing catastrophically. I just can't imagine having that many large holes in the bottom pane to be worth the risk.

I do live in SF so maybe I'm just a bit more paranoid about earthquakes.

 

[teesquare]

Mark:
My personal tank has 14 holes in the bottom of it. 10 are for 1" plumbing (1-3/4'' holes) and the remaining 4 are for 2'' plumbing (2-7/8'' holes).
That tank had been set up and running for 8 years, with NO leaks or catastrophies.
I have a another tank being built now that has 18 holes in it.

There are some rules to adhere to as far as how close together, and how close to the edge. As well, the aquarium must be supported properly.
But in point of fact - the opportunity for failure occurs more often when the BACK panel of glass is "swiss cheese". This is because - in a typical tank - the back and frone panels of glass are the long sides and cannot be supported the way the bottom can. ( The "bending" of the glass under load is called deflection)
Your fear of failure is valid - *IF* - the stand has no solid top, and has no extruded foam to support the bottompanel of the tank.

I suppose having done and seen most things in this hobby wrong first, then having to learn how to prevent or fix them has helped me not be afraid - but it has also forced me to do the real research before trying something new.
(That is how I came to believe in the use of silicone sealant on bulkheads as well - I have NEVER had a leak.)

T

 

[A.K.A. ReefDoctor]

Once I started using G/E household glue (Silicone sealent) I Never Had a problem with leaky bulkheads. Then The G/E glue became unavailable so I now use a General Aquarium sealent and have no problems to date. This cover over 300 Bulkhead installs to Glass tanks and or Acrylic sumps. I do clean and perp all surfaces with acetone. Replacing bulkheads for break down and re installs is a bit more labor intensive however, but still no leaks with a good cleaning and prep for the new B/H install.

 

[teesquare]

Right on....!
And.....I will bet you did not have to "cut out" bulkheads.
T

 

[jlinzmaier]

<a href=showthread.php?s=&postid=15030892#post15030892 target=_blank>Originally posted</a> by teesquare

There are some rules to adhere to as far as how close together, and how close to the edge. As well, the aquarium must be supported properly.

I acutally talked with Derek at miracles about this when we were planning my tank and stand build. My tank stand is stainless steel and built like a beast. There is a 2X2 in perimeter with five 2X2in cross braces (tank is 8ft long). To allow for any minor imperfections in either the tank edges or top of the stand I put down a 3/4in layer of plywood then a 1/2 in layer of polystyrene.

Jeremy

 

[teesquare]

Jeremy:
Be sure you size the EXTRUDED polystyreren that is the blue or the pink stuff - to the ze of the bottom pane of glass. NOT the "outside to outside" dimensions.
It needs to be the correct height as well. The height is determined by the distance from bottom edge of trim - which sets on the plywood - to the bottom of the glass.It can be a LITTLE thicker - but no more than 1/4'' at most.
T

 

[jlinzmaier]

Tank is in place resting on the polystyrene I cut it for the full dimension of the bottom of the tank. It didn't initially occur to me that the bracing could elevate that bottom glass pane, so I just cut out a peice of polystyrene from the corner to see how much of a lip there was from the frame and it's only 1/16th of an inch thick. How would I fit a piece of anything 1/16th of an inch thick to fit tight up to that glass. I would assume the polystyrene would give enough so that there isn't a major weight distribution problem.

I'm very interested to hear what you guys think but I'm also going to give Derek a call at Miracles and see what he thinks. The way I have it set up is how he recommended.

Jeremy

 

[teesquare]

Can you qualify "polystyrene"....?
White= bead-board - typically a < 1lb per cu. ft. density. Quite soft.

Pink or Blue = two common brands which are extruded. Much higher density product.
T

 

[jlinzmaier]

<a href=showthread.php?s=&postid=15034539#post15034539 target=_blank>Originally posted</a> by teesquare
Can you qualify "polystyrene"....?
White= bead-board - typically a < 1lb per cu. ft. density. Quite soft.

Pink or Blue = two common brands which are extruded. Much higher density product.
T

I have the pink extruded polystyrene. I'm guessing too dense to allow for adequate compression to distribute the weight evenly - right?? Damn!! The more I think it through, I'm convicincing myself I need to get a layer of the less dense white bead board underneath. Good thing there's no water in the tank yet, but it's still 900+lbs to pick up to put another layer underneath.

Derek was out of the office by the time I called him so I'll have to post back after I talk to him tomorrow.

Jeremy

 

[teesquare]

Actually - I prefer the Pink or Blue type over the White Jeremy!
The reason is it will compress with the weight of the water, should it need to give a bit, but it is not :"mushy" like the White poly. bead board.
The only thing I like to do differently than you have done is:
1. cut the foam to fit th area of the glass - not extending under the trim.
2. if the height of the space between the bottom of the glass and the plywood the tank trim rests on is -say - 1/2'', then I use 1/2'' pink foam board - then put a 1/4" layer of the White softer bead board on top of it.
It is going to be o.k. - Just take deep breaths, don't react to the panic of the moment, and think it through.:rollface:
T

 

[jlinzmaier]

<a href=showthread.php?s=&postid=15034818#post15034818 target=_blank>Originally posted</a> by teesquare
Actually - I prefer the Pink or Blue type over the White Jeremy!
The reason is it will compress with the weight of the water, should it need to give a bit, but it is not :"mushy" like the White poly. bead board.
The only thing I like to do differently than you have done is:
1. cut the foam to fit th area of the glass - not extending under the trim.
2. if the height of the space between the bottom of the glass and the plywood the tank trim rests on is -say - 1/2'', then I use 1/2'' pink foam board - then put a 1/4" layer of the White softer bead board on top of it.
It is going to be o.k. - Just take deep breaths, don't react to the panic of the moment, and think it through.:rollface:
T

LOL!!LOL!!LOL!!

This is such a huge build it doesn't take much to get me panic stricken!! I've obviously never done a build this big. I thought about and reasearched this project for over a year before I had the tank built. I had long dicussions with Derek about how he could build this tank so that every precaution was taken and every extra measure was in place to prevent 420 gallons of water spewing all over my house 5 or 10 years down the road. (thus my reasoning for this thread to get any secrets about the best way to seat my bulkeads)

The difference between the trim on the tank and the bottom pane is only 1/16th of an inch. I'm sure my glass can't withstand 1/16th of an inch in flexion but I'd have to think there is some sort of settling that occurs with the polystyrene to sink that trim down a bit.

Appreciate the feedback! I'll post back what Derek says.

Jeremy

 

[teesquare]

I see - they do not build a a "floating bottom" tank...
You just need an absolutely flay surface, and the white bead board then.
Let me suggest a type of plywood called "TDO". This is a film faced plywood which has 50% higher density than traditional plywood, and will handle all of the potential moisture exposure you will have. And it is much flatter than the plywood you normally encounter. It is used to make concrete forms where a "slick" surface on the concrete is imperative.
My next choice should there be no source of TDO is Advantech.
Advantech is a resin rich type of OSB ( Oriented Strand Board) and is used largely as the preferred material for sub-flooring in construction. Heavier more dense, and flatter than plywood.

So - *IF*, and I repeat *IF* you feel you absolutely have to remove the tank - I would look into these materials. But they are not absolutes - just what I have found that work well for me.
T

 

[jlinzmaier]

In your opinion, is it worth lifting the tank to put a layer of white bead board??

Jeremy

 

[teesquare]

As you don't have a floating bottom in the tank - I would say no. 1/16'' of an inch is not much of a gap, and you may be surprised as to the amount to dflection possible in galls tanks. But - you do need to ask the question of Miracles before deciding.
T

 

[jlinzmaier]

Well, Derek said it wasn't a big deal. He said if I wanted to put the effort into getting another layer of white foam board in place it would be good, but isn't absolutely necessary. He said the deflection of the glass will allow for contact with the current pink polysytrene at 3in past the edge and the vast majority of the weight of the tank would be supported.

I'd rather be safe then sorry so I'll find a way to get a layer of white foam board underneath.

Really appreciate your help T!!

Jeremy

 

[teesquare]

Not a problem Jeremy!
Wish you were closer - I would come help you move it.
T

 

[Reefski's]

<a href=showthread.php?s=&postid=15026459#post15026459 target=_blank>Originally posted</a> by Matt_Wandell
You are asking for a disaster Swiss cheesing your bottom glass like that.

why do you say that? speculation or have you evidence? i have spoken with Paul at oceans motions and he has a lot of experience and has not seen failures.

i too like the silicone grease, just a thin layer does the trick.

Carl