Acrylic Fabrication Q & A

[Turbo's Aquatics]

but what happens when the tank is filled and the acrylic naturally bows even more?

I was trying to think about how that would play out...unsure

18" tall. It has 3/4" material for the four sides and 1/2" for top and bottom.

well that's slightly overbuilt IMO, or at worst, correctly built. I would do 1/2" for 18" tall then bump it up to 3/4" since it's almost 8' long. But I would argue that one could use 1/2" for 24" tall up to 6' long, then bump it to 3/4" for 96" long.

So with that logic, there's a pretty decent safety buffer in there. It's just the built-in bow question now

 

[Lowell Lemon]

We built a custom machine to plane off the top and bottoms of tanks up to 72" long with thermally formed corners. Used other methods for tanks longer than that.

 

[Turbo's Aquatics]

Well aren't you fancy. Here I am with a board with sandpaper glued to it

 

[Lowell Lemon]

Well aren't you fancy. Here I am with a board with sandpaper glued to it

Yeah I use that on larger tanks.

 

[Koleswrath]

Hey guys, I'm starting an overflow box for a small 15 gallon tank and looking for suggestions on how you'd weigh down or clamp these tiny sides. Since this is the internal part of the overflow and won't see any significant pressures I just held held it down for a couple minutes and threw a clamp on my square block and called er good. I'd like a better method for the external box since that will be slightly more critical to the long term integrity of my living room floors.
Thanks,
Greg

 

[Turbo's Aquatics]

for small pieces like that, I just balance a small weight on it. Sometimes I hold it in place with a long piece of blue tape just to keep it from tipping over

 

[Lowell Lemon]

With small parts if they fit tight and clean we just used capillary action without pins. I would only do this with material up to 6mm or .236 thick materials.

 

[Koleswrath]

With small parts if they fit tight and clean we just used capillary action without pins. I would only do this with material up to 6mm or .236 thick materials.

Good to know. I tested a capillary weld on a small piece of 1/8" acrylic from this brand and it was surprisingly difficult to break off (even with just that 1/8" cross section being welded). I'm pretty sure this is a Chinese brand of acrylic though and seems to take a longer soak time to soften up so I'll stick to the pins for a bit of a safety net. I really hate that you can't see your joint after it's done!!

 

[cromag27]

Good to know. I tested a capillary weld on a small piece of 1/8" acrylic from this brand and it was surprisingly difficult to break off (even with just that 1/8" cross section being welded). I'm pretty sure this is a Chinese brand of acrylic though and seems to take a longer soak time to soften up so I'll stick to the pins for a bit of a safety net. I really hate that you can't see your joint after it's done!!

i wouldn’t trust the “toughness” of the weld to be an indicator of it being water tight, however.

 

[cromag27]

anybody still using any of the old thickness calculators? don't remember which were deemed to be somewhat accurate.

 

[Turbo's Aquatics]

This is what I have generally gone by - from James Steele

start with 3" eurobrace on any tank..

24" high, use 1/2" minimum
30" high, use 3/4" minimum
36" high, use 1" minimum

with these in mind, I recommend a 6" wide crossbrace every 24" of tank length. So a 48 x 24" will have 3" eurobrace and a 6" crossbrace. If the same tank were 72" long - just one more crossbrace. At 8' length, I recommend jumping up one material thickness to keep deflection down.

There are times when someone's lighting scheme doesn't match the above formula. Ie., if someone wants an 8' tank but only 3 cutouts in the top. In such cases, I recommend increasing the eurobrace width to 4.5" and increasing the width of the crossbraces to 8".

I've been using this formula, 1.5" radius corners, and material thickness minimums above, for many years and I have *never* had a tank fail.

If someone doesn't want the crossbrace - they simply have to make the material thicker, and/or increase the width of eurobrace to maintain rigidity.

 

[Koleswrath]

Thanks again for your help everyone. This little guy holds water like a champ. (note to self - take paper off areas you can't fit your fingers in BEFORE gluing up!)

 

[cromag27]

This is what I have generally gone by - from James Steele

mainly for ato containers.

 

[Turbo's Aquatics]

mainly for ato containers.

Same rules. But you can do 1/4" all day long for most ATOs and sumps

 

[Koleswrath]

Very proud of this bubble free joint. This thread has opened up unlimited possibilities for me. Thanks again everyone!

 

[Koleswrath]

First sump under my belt. Went pretty smooth using the guidelines in this thread. All beautiful joints except the raised baffle. Had a tough time reaching it with my bracket in place but thats alright.
And it doesn’t leak!!!

 

[Turbo's Aquatics]

Did you add the "up" baffle after all the other panels were installed, or did you bond everything to one panel and then flip & bond to the second?

 

[Koleswrath]

Did you add the "up" baffle after all the other panels were installed, or did you bond everything to one panel and then flip & bond to the second?

I bonded both baffles to the first side then flipped for the second side. The first side joint is good but after I flipped it I couldn’t figure out how to shim perfectly so I just focused on trying to shim the first baffle as that was the important one. I also had a bracket in there to keep things square so I didn’t have the best access and only put one pin in.

 

[Nick4978]

I'm going to be making an ATO which is 20" tall, 12" long and 12" wide (a bit over 100 lbs. completely filled).

I want to be able to put handles on it so that it can be moved around. What would I need in order to put a pair of handles on the sides so that it could be lifted full of water without the bottom falling out or something? Or would that even be possible or feasible? Thanks!

 

[Lowell Lemon]

I'm going to be making an ATO which is 20" tall, 12" long and 12" wide (a bit over 100 lbs. completely filled).

I want to be able to put handles on it so that it can be moved around. What would I need in order to put a pair of handles on the sides so that it could be lifted full of water without the bottom falling out or something? Or would that even be possible or feasible? Thanks!

Not a good idea moving 100lbs of water around. One wrong twist and your back is toast for a few weeks. By the way I fabricate and install stone counters so I know a thing or two about protecting your back. I also think moving a weight that sloshes around is a bad idea.