Acrylic fabrication questions? I can help!

[dattack]

Anyone? 1/4", 3/8" or 1/2" on the exterior box?

With external overflow boxes that long, are you going to have acrylic strips to prevent bowing or maybe even a small euro brace. Even if you use 1/2", it's going to need some kind of support every 6 to 12 inches to prevent bowing.

 

[SFish]

So two braces is enough for a 72x30x15?

Also is it cheaper to buy a glass tank vs making one out of acrylic in general?

 

[CuzzA]

Acrylic fabrication questions? I can help!

With external overflow boxes that long, are you going to have acrylic strips to prevent bowing or maybe even a small euro brace. Even if you use 1/2", it's going to need some kind of support every 6 to 12 inches to prevent bowing.

Yes in my illustration above you'll see 2" braces every 12 inches. Perhaps I should go every 6 inches?

I know 1/4" is likely out of the question, but would 3/8" work safely? If this were a tank I would have a better idea, but for a floating box I'm unsure of how the weight of the water will effect the material given the dimensions.

 

[dattack]

Yes in my illustration above you'll see 2" braces every 12 inches. Perhaps I should go every 6 inches?

I know 1/4" is likely out of the question, but would 3/8" work safely? If this were a tank I would have a better idea, but for a floating box I'm unsure of how the weight of the water will effect the material given the dimensions.

i think 1/4" inside is fine. 3/8" for the outside box with your bracing plan is good.

 

[SFish]

So two braces is enough for a 72x30x15?

Also is it cheaper to buy a glass tank vs making one out of acrylic in general?

 

[Acrylics]

So two braces is enough for a 72x30x15?

Also is it cheaper to buy a glass tank vs making one out of acrylic in general?

If 15'' is your height? then yes 1/2 will work, even 3/8.

Agreed, if using 1/2", one cross-brace is fine with a ~3" eurobrace, 2 cross-braces would obviously be better 2 cross-braces would pretty much be mandatory with 3/8" material if I made it so would suggest similar..

Generally speaking, it is far cheaper to buy a pre-made glass tank of that size than to build one from acrylic, far cheaper.

James

 

[Acrylics]

Hasn't been any activity here for a while. Any update with a quick how-to video?

I tried, and tried again, Photobucket keeps deleting them. If you know of another alternative, I'm open to it

James

 

[Floyd R Turbo]

I tried, and tried again, Photobucket keeps deleting them. If you know of another alternative, I'm open to it

James

Upload to YouTube?

 

[Floyd R Turbo]

Ok, my acrylic experts! I have decided to build my own overflow box and I have a question.

What acrylic thickness should I use for my external box which is part of an internal/external overflow held together with 6x 1.5" bulkheads (bean drain)? I'm using 1/4 inch on the internal and was thinking I should use 1/2 inch on the external, but if I can "safely" get away with a thinner dimension that would be nice to know. The dimensions for the box are 71 x 4.5 x 7.

Here's a sneak peek at what I'm doing for the 310 upgrade. I'm going to great lengths to conceal all equipment and the box. Plus I'll be incorporating a shadowbox background behind the tank. This was a decision made after the glass tank was drilled, otherwise I would have done my hole placement differently. Nevertheless, I can't change it now and I'm not worried about it as I believe I have a solid plan. In the first picture you see an exploded illustration of all of my cuts for the acrylic. Bracing, Front, Back/Sides, Bottom. In the second picture is the pukani overhang that will be attached to the front of the box. I'm not to concerned about weight because A) It's light weight pukani and B) The pond foam I used actually adds a decent amount of positive buoyancy.

Anyway, any and all suggestions are welcome. Thanks in advance!

Oh, don't mind the zip ties and plastic yellow markers... All that rock is going in the Gulf of Mexico for a few months.

Edit: Also, I plan on welding the bottoms for the inside dimension rather than the outside. I'm assuming this makes no difference being that the box is floating in air rather than on a stand like an aquarium. Right?

I'm a bit confused.

Is this a pic of your internal and external box? Why the 45s?

6 drains? Why 6? Are you talking about pass-through bulkheads, or are you planning on doing 2 of each drain type (2 siphon 2 OC 2 emerg)? FYI if the latter, not going to work.

 

[CuzzA]

Hey Floyd,

Yes, this is an internal/external box with 6x 1.5" pass throughs. (We need to come up with a simpler name for internal/external box, perhaps inex overflow, lol) Anyway, the bean drain will come out the bottom of the external box using p traps.

As for the 45's, this is in an effort to make the overhang and shadow box background look natural. A straight line plus the height of the internal box wouldn't look right. I don't anticipate any issues because even if I don't get a 100% perfect seal, it's inside the tank. It may even be beneficial to minimize any settling within the very narrow box.

What are your thoughts on 3/8" acrylic for the external box?

 

[Floyd R Turbo]

Ok so I get the 45s on the front facing internal panel for aesthetics, what I don't get is in your pic, the top part that shows the 6 bulkhead locations, is this supposed to be the back panel? That should be square. The only panel that should have the bump out is the bottom.

As for bonding the bottom inside vs outside, with all those 45s, good luck fabricating that to fit inside, I would never attempt that, it's going to be a nightmare! Bond the bottom on last and flush trim, that will reduce your headaches by at least 50%. The other 50% of headaches will still exist due to the front face of the overflow box. My advice would be to do that in a phantom method. i.e. make the overflow box rectangular (simple) and then bond on some fake bump-outs that give you the look you want externally but are 100% aesthetic. Much, much simpler not having to mess with 45s.

The perfect seal in the tank is still an issue, because lets say you have a leak along the bottom seam and a long term power outage. Your tank will drain down lower than the top of the overflow box, limited only by the lowest point of the inside of the siphon line. So you could dump another several inches of tank water over time into the sump via slow leak. For a 310 this could be 20-30 gallons, which could overflow your sump if not accounted for.

 

[Floyd R Turbo]

Other option: make front panel using heat bender. A little sanding of the bent areas, bond together (bottom last).

As for the external box, with it being that long, you will want some bracing in there as mentioned, but I would think 3/8" would do. I've seen it done with 1/4" also and that is a possibility as long as it's not too deep.

Also you will want to consider that a shallow ext box can be problematic. You want enough depth to be able to keep the pass-through bulkheads submerged for the most part to reduce bubbles (which will get pulverized by the siphon), and be able to put the siphon low enough so that the water level above it prevents air sucking in.

 

[CuzzA]

Thank you for the info.

So, I don't think I will miter both joints. Just the short 3.125 pieces. Basically just put the one piece on a 45 degree fence and cut both ends the same. I'll have to cut off the tips on the tops where they join with the horizontal pieces. But we're only talking a total width of 1 inch, so I anticipate the short length will be much easier to work with.

As for the picture, the top half is the internal box and the bottom half is the external box. The white dotted lines represent the pass through bulkhead location on the top box and the white dotted lines represent "both" the pass through bulkhead location and the internal box location as it would be setup. Basically the white dotted lines are simply a visual to see where everything lines up. The external box will be a full rectangle typical of any other external box. Only the internal box will have the bump outs. In my other picture of the rock I cut eggcrate to the same dimension and attached the rock to it with pond foam. This way it won't have a straight line and will also give me a few more inches for the images in the shadow box illusion of an infinite reef. Similar to the popular shadow box thread on here.

Which leads me to your next point. I plan on making the external box height equal to the tank. To achieve this I am considering either using very thick gaskets or adding acrylic to each pass through to bump the external box out so it can get past the rim of the tank. Any thoughts on this? My thoughts were by having the external box 7 inches tall and to the top of the tank I can then extend the height of the drains to submerge the pass throughs. Sound right?

Good point about making sure the internal box doesn't leak. I hadn't thought of that, but will make it a priority that the internal box is water tight.

Thanks.

Cut list in order from top to bottom of the picture:

Internal Box:

Braces
Front panel
Back panel with side pieces
Bottom panel
Illustration of bottom panel highlighting the mitered joints

External Box:

Braces
Front panel
Back panel with sides
Bottom panel

 

[Floyd R Turbo]

Bump out the external box with pieces of 1/4" acrylic bonded to the external box. That's the best way I have found.

Gasket/bulkhead order usually is (starting with external box)

Flange
Ext box
Gasket
Tank wall
Gasket
Internal box
Nut

So make sure that you have enough room in the external box to insert the bulkhead, and that it sticks out far enough through to the internal box to allow you to install the nut, but not so far that the bulkhead pushes against the front panel of the internal box (preventing you from tightening it). You only have a 1" deep internal box, that's pretty tight.

Also what thread me off is the bottom of your box has the 45s. I thought that was the front. IMO you may have an issue with trying to keep your pass-thru bulkheads so high relative to the rim of the tank. Not enough room for proper BA operation IMO

 

[CuzzA]

Bumping out with acrylic is what I'll do. Seems like the smart way to do it. With a one inch internal box the challenge will be finding the correct shaft length on a bulk head. Although I suppose I could just go long and cut it down. However, standard ABS bulkheads have 2.5" shafts. So if my calculations are correct.

From inside out:

.25" acrylic internal box wall. 1/4"
.125" gasket. 1/8"
.625" glass tank wall. 5/8"
.125" gasket 1/8"
.375" acrylic bump out. 3/8"
.375" acrylic external box wall. 3/8"
.375" nut. 3/8"

Totals 2.25" or 2 1/4".

This leaves me with .25" or a 1/4" to spare.

The remaining length inside the internal box will be .625 or 5/8" plus the room needed to get the nut on .375 or 3/8" which equals exactly 1 inch. I could make the internal box an 1/8" wider or simply shave off a little bit of the edge of the bulkhead. There's no threads on the first 1/8" or so of the bulkhead.

As far as BA operation I don't see where I would have any problems. As long as the water falls slightly below the weir and the pass through is submerged/partially submerged it should work just fine. The drains can be between the pass throughs as they will be inside the shadow box and I can put objects (painted foam board) in front of them to hide the pipe. This may allow me to not fully submerge the pass throughs as there will be enough distance for any bubbles to rise and pop. I could also use a baffle if necessary. Nevertheless, all of this will be dictated by the height of the p traps in the external box right? So, it may take some trial and error but with the external box being equal to the height of the tank I should have no problems with excess water in the external box upon startup. Obviously it will be advantageous to have as quick of a start up as possible. Which I think I will be able to achieve by using the p trap, stand pipe, 45 into the sump, pipe, 45 down, gate valve and finally pipe terminating at the water level.

Thoughts?

 

[Floyd R Turbo]

The gaskets are more like 1/16"

1/4" is OK but take 1/8" off of that and now you're getting pretty tight. But trimming 1/4" off the BH is going to be fine.

Also remember that acrylic is imperial thickness, so 1/4" acrylic is actually 0.236 and varies depending on where you cut it on the sheet, I've seen 1/4" as thin as 3/16" or even a bit less.

In an internal/external BA setup, the siphon controls the level of the water (obviously) and is limited to an extent by the level of the P-trap for the OC. The water will start to flow through that as water level rises so in a way the OC controls your operational range. Then your placement of the level of the E drain and the OC airline would control the maximum level. With the external box level with the top or the tank, this gives you a good operational safety range.

Then since the water level in your internal overflow is going to be a bit lower than your tank water level, you should probably position the E drain to be at or just below the normal operating level of the tank. As the water rises, and gets to about 1/2" above the E drain, it will kick in. At 1" above the E drain, it will get occluded for the most part, so this would be the tank water level equalling the external box water level. At that point your OC will kick over to siphon also and try to purge while the Siphon is purging, and it should keep the box draining fine as the OC kicks in and out of siphon while the siphon is purging.

how big are your drains?

 

[CuzzA]

1.5"

 

[Floyd R Turbo]

6.5" tall external box is gonna get a bit tight with 1.5" drains & plumbing...IMO

 

[CuzzA]

Oh yeah. Everything is going to be tight and a challenge. But I have time to tinker as my rocks sit in the Gulf. Worst case it's an utter fail and I'll be rebuilding the external box looking for a different solution for the realistic background. As with all systems, so much is dependent on something else and I'm putting a big challenge ahead of me. If achieved though, I have no doubt it will look fabulous with the one caveat of keeping the back glass clean. Tunze strong on a pole is the solution I've came up with there. Oh boy.

Thanks for your help.

 

[karimwassef]

Hi. I need to cut slots in a horizontal acrylic sheet to accommodate a number of precisely placed vertical sheets. The design is intricate and made with 1/2" and 1/4".

The smallest vertical sheet is 1/4" thick. I'd like the base (slotted) piece to be 1/4" too.

I don't have a router. I'm not sure it's the best tool to make these square corner 1/4" slots?

Here is the view from the to. Where the vertical sheets are is where I'd like the slots in the horizontal sheet to be.

<a href="http://s1062.photobucket.com/user/karimwassef/media/17789967-CA6D-4132-A48D-B200AC361E65_zps4jba4hug.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/17789967-CA6D-4132-A48D-B200AC361E65_zps4jba4hug.jpg" border="0" alt=" photo 17789967-CA6D-4132-A48D-B200AC361E65_zps4jba4hug.jpg"/></a>

There are two horizontal sheets, by the way.. Top and bottom