Acrylic fabrication questions? I can help!

[kenny77]

Acrylics

for my LFS I will be having 3 coral tank. 48" x 24" x 12" high. thats about 60g. What acrylic should I use. 1/4" with 2" euro all around and 2" center brace. or 1/2" for the walls?

will 1/4" be strong enough??

[Acrylicman]

You would be surprised the strength of acrylic. (tensile). Although I would need to see pictures, to give you a realistic assessment.

Steve

[bchbum189]

id like to see pics of the stand, just cause im curious to see it

[Acrylics]

Kenny,
Many years ago I made some frag tanks for an LFS just as you are describing from 1/4" material. They are still in use so there is plenty of strength but they bow more than my tolerances allow. I've actually thought about rebuilding them for free using thicker material.
The way I do them now is use 1/2" with a 3" eurobrace with no crossbracing, or 1" vertical panels with no eurobrace (rimless). 3/4" rimless holds water but starts to bow some.
I like to see things that I don't have to worry about, ever

James

[kenny77]

but If I use 1/4 with 2" eurobrace and 2"center brace. will it still bow?

[-TS-Vash]

Ill post a pic tomorrow some time after noon. Thanks.

[-TS-Vash]

[Acrylics]

Originally posted by kenny77
but If I use 1/4 with 2" eurobrace and 2"center brace. will it still bow?

Yep

James

[kenny77]

thanks Acrilics. So all I need is to build it as I plan but with a thicker acrylic (1/2").

that mean that for my show tank I will need 3/4 maybe 1" acrylic. right.

here is a link.

http://reefcentral.com/forums/showth...readid=1103432

[Acrylics]

1/2" would be great for the frag tanks, I'd personally use 1" for the show tank. I've seen a coupla of these style tanks crack due to bad engineering though. It is also critical to have a stand that supports it properly on both levels. An easier way might be to make the whole tank 36"H and just put a big pile of LR on one side and some sort of fascia to give the illusion of a bilevel tank.

HTH,
James

[kenny77]

I thought about that on making it 36" high and doing the effect with the rock. but after playing around with photoshop and drawing how it will look with a stand I'm gonna go this way. If I have to use 1" I will do it. The stand will be build in metal. This is were I think I will have to messure twice since I beleive it have to be 100% level to support both size.

[-TS-Vash]

Do you think the stand in the pics i posted will hold a tank ok?
I can give you better pics if you want.

[Acrylics]

I personally would not put a tank on it. I know of a coupla companies that make them, I just don't like the idea though it may hold just fine.
For acrylic tanks, the weight will cause downward deflection on the stand top thus the tank bottom, leaving bulges on the bottom of the tank. I've seen this scenario play out on a coupla tanks here on RC
For glass tanks, it is my opinion that the allowed deflection will not support a glass tank evenly, putting much stress on the silicone joints. Ie, if the stand bows down, the silicone joints will have that much more stress on them. I don't know with absolute certainty that any failures would occur, but I personally wouldn't risk it.

James

[RELIA]

i just had tank built by tank maker here locally its 96x30x30 its 3/4 on front and back and sides bottom and the top is 1/2 inch my concern is is the top suppose be 3/4 or is the 1/2 fine on the top

[-TS-Vash]

Acrylics Thanks for the help i think ill pass on using the stand then.

[Acrylics]

Relia,
I don't particularly like it, but it's kinda "normal" to use thinner material on top & bottom. If the bracing is adequate - should be fine. FWIW, I'd much rather see thicker material on the vertical panels and thinner on top & bottom than the other way around. Safe to assume ATM built it? If so, they normally use good bracing on top.
Many companies use 1/2" all around on that size tank which IMO bows far too much for my taste but still holds water.

HTH,
James

[RELIA]

im planning on building the sump myself what thickness would you suggest it going to be 81x20x20

[slavearm]

I came upon 3- 12" dia 1/4 wall 15" tall extruded tube for REALLY cheap. I was planning on buying a 30-36" piece of cast, but the stuff was so cheap, I couldn't resist. I am going to make myself a killer Skimmer. Now... I need a piece that is longer than 15", so I must join two of the tubes together.

That routing jig would be nice, but I am thinking I may just have to use the ol' sand paper sheet on flat surface trick to get them nice and flat. Any advise on joining a couple of the tubes together?

Thanks in Advance.

[Acrylics]

Relia,
Depends on how it is braced, but IMO 1/2" is the minimum.

Slavearm,
Are you cerain it's extruded? I know of no company in this country that extrudes 12" diameter tube, always spun cast.
The jig only works if the table is *perfectly* flat so... Joining tubes end to end is not the easiest thing to do and get good joints, but is possible. Prolly the easiest way is to bevel the two pieces, one with a (45degree) bevel towards the inside and the other towards the outside. This will raise the gluing surface area by roughly 40% and alleviate many of the worries of having perfectly mating pieces. Joints won't be *perfect* but plenty strong enough.

HTH,
James

[slavearm]

It certainly looks extruded by the fine wavy lines running along the length.

I love the idea about doing the bevel. That will even make the glueing process 100% easier. Man you are a genius. It will be hard to get a horizontal glueing surface, but shouldn't be too bad with the 45s. My normal weldon 4 should be fine right? Or should I go with something a little more goopey?

[Acrylics]

I'd prolly use 4, let it run a little, as long as it's strong.

Those might be buffing lines from the final finishing at the factory. Extruded tube is usually kinda yellowish and not real clear at all, at least compared to cast.

James

[bchbum189]

Ok, so with the wo 40, i have just been running a bead down the piece to be glued, and setting it on the other piece. Problem is i cant place the piece perfectly where it needs to be, so there is always some moving i have to do, which smears glue across the surfaces. Is there a way to get the wo 40 into a seam in a capillary style way??

[Acrylics]

Originally posted by bchbum189
Ok, so with the wo 40, i have just been running a bead down the piece to be glued, and setting it on the other piece. Problem is i cant place the piece perfectly where it needs to be, so there is always some moving i have to do, which smears glue across the surfaces. Is there a way to get the wo 40 into a seam in a capillary style way??

What is generally done is to machine the vertical piece at a slight angle and raised off the horizontal piece a little (held by clamps), the 40 is then applied using a syringe. If you raise it just enough, surface tension will keep the 40 from running just as it keeps solvent from running in a solvent joint.
BTW, the angle changes with thickness; for 1/4" material - maybe 15deg angle, for 1.5" material - maybe 5deg angle. You don't want the gap to be too big or the 40 won't attach to both pieces. Experiment a little to find the comfort zone for the material you are using.

HTH,
James

[slavearm]

Originally posted by Acrylics
I'd prolly use 4, let it run a little, as long as it's strong.

Those might be buffing lines from the final finishing at the factory. Extruded tube is usually kinda yellowish and not real clear at all, at least compared to cast.

James

Clear as can be. Maybe I got an even better deal than I thought.

Whats the best way to get pipes in and out? Bulkheads wont fit real well (I checked tonight) due to the contour. Thread them and then use 4052 (I think this is the acrylic to PVC weldon) on the threads? I don't really like uniseals all that much. Or just cut the hole to match the pipe and use a two part epoxy? It looks like on my deltec, they just epoxied a union to the acrylic tube.

Two of them will have to support the weight of 1 pump (an eheim 1262 if that matters.)
Thanks,

Shane

[Acrylics]

Personally, I'd drill & tap the holes. For weight support, you may wish to glue a block under the pump.

James