Building an acrylic aquarium...how to?

Hey guys, a buddy of mine and I want to set up around a 20 gallon acrylic peacock mantis tank when we move into an apartment together some time next year. I've got a list of questions, and hopefully someone knows the answer to one of them. I've shopped around, and it looks like the easiest route to take would be to get the acrylic pieces pre-cut online and shipped to us according to our specs, and then glue them together here. I'll probably build the stand myself, and it'll probably have a sump/fuge underneath with maybe a ten gallon. Depends on what we can fit underneath the stand. I'm shooting for maybe a cube style tank, at least "square". I don't want to to be a true AxAxA cube, more like an AxAxB unit if that makes any sense at all.

This friend of mine and I road tripped up to knoxville to one of our favorite LFS's of all time, and I heard this loud POW behind me. It sounded like a pistol shrimp, but louder. I turn around, and there are 3 peacock's staring at us. One was this awesome blue/purple color, and the others were your average peacocks. I have a mantis, but I fell in love with these guys. They are so so so so much cooler than Princess my Caribbean Rock Mantis (and she's pretty awesome). So my friend and I want to build/share the tank in college.

My questions are:

What would be a good thickness for the acrylic? 1/4"?

What glue would be used on this acrylic to hold it together? I know straight up silicone won't cut it. I know there's a special waterproof glue somewhere that would be able to do it, I just don't know what.

Anyone know of a good website to get precut acrylic from? If we can't find custom cutting, would we be able to cut it ourselves? What about drilling holes for the overflow?

Thanks in advance for any advice or replies.

And yes, when this build gets started I WILL put up a build thread. With lots of pictures.

 

I tried to whip up some drawings in Microsoft paint...but it definately ain't AutoCadLT let me tell ya. So I just sketched out some stuff, including possible LxWxH dimmensions and the gallon volume those would amount to. If you can read those numbers anyways...

The numbers on the right side of that page are, from top to bottom, as follows:

1 gallon = 231cube inches
+20 gallons = +4620 inches cubed

20x20x14
= 5600 inches
=24.2424 gallons

22x22x12
=5808
=25.1428

24x20x12
=5760
=24ish gallons

24x16x14
=5376
=23.27 gallons

Yes, I am majoring in Mechanical Engineering thank you very much Engineering is the only field I can see myself in...except maybe a math teacher. Or something. You like?

 

Jwin, have you been to melevsreef.com? He makes his own tanks from acrylic and probably has all the info you need as far as tools and the stuff to glue it together( I think it's called weld-on) and how to do it. As far as getting the acrylic I bought mine at Home depot. They have 4' x 8' sheets and some cut to certain lenghts but I don't know if they cut any other sizes for you. Probably call and ask. I used a skill saw and jig saw with fine toothed blades to cut mine but you have to be very careful or it will crack or chip it. I have also experimented with heating it up and bending it with a small torch they sell at Home Depot for about 15 bucks. Works pretty good and looks alot better than than piecing it all together. HTH.

 

Check out Google Sketchup, decent free CAD tool, with a bit of an awkward interface if you've used Maya, 3DS, or AutoCad, but it's usable and free.

Tank looks good.

To glue (really called welding) acrylic sheet you need a methyl chloride based adhesive like Weld-on #15. it's water thin so your fit has to be very tight. like tight enough you can't drag a hair through. Lots of clamps help.

You can bend acrylic with a heat gun - don't use a gas torch or you'll scorch the plastic (unless you're really good). There are heated strips you can buy that are for the purpose, as well as blocking/braking tools for a professional look, but personally i find the distortion of a curve to be distracting. You can polish and glue a seam so it looks like a single cast structure.

TAP or Regal Peidmont plastics is a much cheaper source of sheet, and you can get Acrylite FF from them, a super clear grade of cell cast sheet. They will cut to shape, usually for free, and will further machine and polish edges for a fee. they also often have a "short and discards" pile with all kinds of cool stuff for making over flows and stuff.

I would go with 5/16 or 3/8 also, not because it needs to be strong, but because it will be easier to weld.

If you cut it yourself make sure you have the right tools. A table saw with a 200 (or more) tooth blade (for a 10") made for cutting plastic will set you back about $100 for the real deal, or $60 for a cheaper "veneer/plastics" blade at Home repot.

A spiral router bit made for acrylic gives a much cleaner cut with virtually no chipping. You'll need a good router table or guides to keep it all square. Make sure the bit you get is for the thickness you choose, the angle of the spiral will vary (you want, IIRC, 1.5 turns on the plastic at all times).

There's a guy on here with a laser for cutting sheet, you might hit him up, see what he'd charge.

As soon as my strep clears up I am going to be doing the same thing, I've been wanting a mantis since before I knew what they were - I saw them on Natgeo 5 years ago. I'll race ya!

-Doug

 

Why not just spend the whopping $30 at petsmart on a new 20 long and be done with it?

 

just made this up for ya, if you have a sketchup account I will add you as a collaborator if you want to edit it.

Mantis Tank by GreyMatter - Google 3D Warehouse

-Doug

 

On the off chance a mantis should hit the glass it would shatter.

If you can sell me a 20g acrylic tank for $50 I'd buy it.

 

Acrylic is fairly easy to work with, if you have the right tools for the job. You need a very clean edge that you will be "gluing." The gue you need is plastic solvent made for acrylics, namely the Weld-On stuff. I use Weld-On #4 and #16 for patch work and seam reinforcements. I have a table saw with a 10" blade with 80 teeth to get a clean edge to work with. If you don't have a clean edge, you will get bubbles in the seam which will lead to a blow out down the road. 1/4" is more than enough, but I would consider reinforcing that with another 1/4" paneling where the mantis may strike the walls. If you need more help, lemme know.

 

Wow thanks for pointing that out! I'll definitely look into that...I've had several moments where I wish I had AutoCAD from school on my home computer.

You'll probably win the race Unless my current mantis kicks the bucket...I've still got a car to pay off, a laptop to buy, and maybe a motorcycle to save up for. I probably won't be starting this sort of project any time soon. Unless I build the tank, stand, and then buy all base rock and let it cycle for a year :

I wish...but that'd be the easy way out. And I'd rather be safe than sorry with a fully grown mantis in a glass tank. Plus, I don't like how the 20 long is "long" and very short, IMO. I want more of a cube style like what you've seen. I think it'd look great and give the mantis plenty of room in all directions. Also, I think building my own tank would make for a great learning experience. I've always wanted to do it. I remember back in my RC plane days, where flying the plane was only half of the fun. Building it was just as good.

I'm probably going to go with getting the acrylic cut online. However, my mom is wanting me to build a canopy for her for the 46 bowfront, and she said "she'll buy me the tools to build it". I don't really know what "buy me the tools really means", but if buying a table saw or band saw shows up in the picture, I'll definitely want to cut my own acrylic. If it's laser cut from a dealership online though, the edge should be about as good as it gets.

How would I glue the edges together? Align the pieces to be glued into their proper places, and then put glue on the seam they form? Or put the glue on one piece, and then put the other piece on top of the glue? Maybe I should just buy really thick glass...silicone is much more enjoyable to work with by the sounds of it

 

Well, if she is buying the tools, and you want to cut your own, a table saw is what you need
I would still weigh glass vs. acrylic. If a full grown mantis strikes the front plane at full force, it's leaking either way. I would be worried about all the scratches over time with the acrylic do to glancing blows and vigorous crab chasing
If your going to build a stand, it will have to be a little different than with a glass tank, so keep that in mind when designing. An acrylic tank needs to be FULLY supported on the bottom to avoid it bowing and stressing, where glass will only need the trim line supported.
For gluing the acrylic, use Weld-On. I haven't had to do actual tank seams so I couldn't tell you as to where to glue. Off the top of my head, I would say both in the seam, and the outside of it.
Also with the acrylic, you would be best to design a permanent top of sorts, again for bracing. Otherwise the sides will all want to push away from each other and cause major stress over time. Same would go for glass if you built it that way, but you would need to do like the plastic trim on both the top and bottom. I wouldn't even know where to start in that department