Acrylic fabrication questions? I can help!

[Aquatron]

Hello,
My 300 gallon tank is 30" tall with a black back and I would like to install a 6" x 30" black return piece on each end. What would be the best way to glue a 1/2" x 6" wide piece to inside of DT acrylic side panel? So when looking at tank you see black back and black 6" returns and each end of tank? I can't turn tank so these pieces will be glued together on the vertical so which glue?
Thanks for the input with this!

Mace

 

[ccuk]

if you were building a tank
180cm by 65cm by 75cm high with brace around top but no center brace .. but brace 100mm wide and 20mm thick what would you recommend for acrylic thickness
thanks stewart

 

[Phixer]

Aquatron: I would glue it up with WO 42. If you must glue vertical make sure you dam it up good with tape so it dosent run. The applicator gun isnt cheap, if you can lug the tank to a shop it may cost less.

ccuk: If I were building a tank 30" tall I would use at least 1" thick material all around. Solid sheet for top with access cutouts. Not exactly what your asking I know but thats how I do it.

 

[dattack]

Has anybody seen a thick acrylic tank glue with acrylic spacers? I saw a local large tank with very thin square acrylic spacers every two feet? Seems like it melts with the large acrylic panels and left there rather than pins. Seems kind of odd but the seams look good.

 

[Phixer]

Interesting, any photos.

 

[SuperNemo]

Yes, photos please.

 

[dattack]

I will try. Give me a few.

 

[smartwater101]

Calculating water pressure and the area it affects.

Calculating water pressure and the area it affects.

I have a question. I'm looking to understand the effects of water on an acrylic tank. Is there a chart for various sizes and thickness that help show where exactly are the specific "stress points" for a tank?

Example: I'm gearing up to build a 62 x 18.5 x 18.5 tank. Using the various thickness-calculators I decided to use 1/2" acrylic. I plan to have two openings in the top piece (so there will be a full rim around the edge and across the center) Although I'm not sure what the measurements should be... 3" around the tank and 6" for the center? 4" around the tank and 7" for the center?

I see lots of recommendations in various forums for various tank sizes but I'd like to have a better understanding of how the water is actually affecting the corners, affecting the top vs bottom, and so on.

So I guess thats two questions. What do you think is appropriate for a tank this size and where can I find info to better explain where the numbers are coming from. Thanks!

 

[kmu]

Hi there, Im in the designing stages of my in wall build.

Im looking into a 72" long by 42" deep by 36" tall 1" acrylic tank

This is what I have so far with 1" acrylic all around.

TOP PLATE
- 3 16"x30" openings on top with 6" bracing all around between openings and between openings and walls.

- Four 2" holes on top for seaswirls

OVERFLOW
- 24" long by 6" wide and 12" tall with two 2" drains.
- Can it be done with 1/1" acrylic instead of 1"?


What do you guys think of the overflow box? can the top openings be made any larger or is 6" of bracing in between necessary?

THX in advance

 

[ccuk]

hi guys what thickness acrylic would you use for a
6ftx5ftx3ft high ...
stew

 

[MattFrancis]

I found a sump I want to use as a display fuge. It has a 1" hole in the side. Is there any way to patch the acrylic to make it look like there was never a hole there in the first place?

-Matt

 

[Phixer]

Check out the book I mentioned earlier. It will provide you with the data you seek.

Check out the book I mentioned earlier. It will provide you with the data you seek.

I have a question. I'm looking to understand the effects of water on an acrylic tank. Is there a chart for various sizes and thickness that help show where exactly are the specific "stress points" for a tank?

Example: I'm gearing up to build a 62 x 18.5 x 18.5 tank. Using the various thickness-calculators I decided to use 1/2" acrylic. I plan to have two openings in the top piece (so there will be a full rim around the edge and across the center) Although I'm not sure what the measurements should be... 3" around the tank and 6" for the center? 4" around the tank and 7" for the center?

I see lots of recommendations in various forums for various tank sizes but I'd like to have a better understanding of how the water is actually affecting the corners, affecting the top vs bottom, and so on.

So I guess thats two questions. What do you think is appropriate for a tank this size and where can I find info to better explain where the numbers are coming from. Thanks!

 

[Phixer]

Double post, sorry. Smartwater, Check out the books mentioned earlier. The data you seek is in there.

Areas of greatest hydrostatic pressure are the bottom seams. The top is subjected to buckling and cracking in the corners of the cutouts.

MattFrancis, even with the 2 part stuff and a close tolerance plug making it invisible would be difficult. If you can get a good fit with just enough room between the plug and the base material i.e 1/8" it's possible to make it look presentable IMO. Maybe use the opening with a bulkhead fitting for a closed loop return line instead?

 

[Phixer]

KMU are you going to radius the edges of the cutouts for the top? Hard to predict if or how the holes on top will effect the structural integrity of the tank. How far in from the edge are they?
36" tall is pushing the limits of 1" thick material IMO. But I don't like bowing.

 

[MattFrancis]

Double post, sorry. Smartwater, Check out the books mentioned earlier. The data you seek is in there.

Areas of greatest hydrostatic pressure are the bottom seams. The top is subjected to buckling and cracking in the corners of the cutouts.

MattFrancis, even with the 2 part stuff and a close tolerance plug making it invisible would be difficult. If you can get a good fit with just enough room between the plug and the base material i.e 1/8" it's possible to make it look presentable IMO. Maybe use the opening with a bulkhead fitting for a closed loop return line instead?

Could you specify what the 2 part stuff is please. I wish I could put a bulkhead there, but its part that needs to be displayed.

 

[kmu]

KMU are you going to radius the edges of the cutouts for the top? Hard to predict if or how the holes on top will effect the structural integrity of the tank. How far in from the edge are they?
36" tall is pushing the limits of 1" thick material IMO. But I don't like bowing.

What does "to radius the edges" mean? Sorry don't understand it, will try googling it.

I have a 48"x48"x24" tall cube made from 3/4" acrylic and it has zero bowing issues.

Is 36" to risky for 1" thick? Ive seen several 40" tall with minor bowing and even a 48" tall with some bowing to it.

I thought that 36" tall was safe for 1" acrylic

 

[Phixer]

What does "to radius the edges" mean? Sorry don't understand it, will try googling it.

I have a 48"x48"x24" tall cube made from 3/4" acrylic and it has zero bowing issues.

Is 36" to risky for 1" thick? Ive seen several 40" tall with minor bowing and even a 48" tall with some bowing to it.

I thought that 36" tall was safe for 1" acrylic

Mattfrancis... check out earlier posts in the thread, lots written about it.

KMU...It's too thin for me, just not how I like to build. However...many commercial Mfgs build to those specs all the time. Safe? probably. But personally I build differently and just dont take those chances when considering with the alternatives, (I dont mass produce and build each tank one at at time, I dont build for profit but rather for quality). Heres why. In Japan, we had a lot of seismic activity (will spare the sea stories of 2011) so I carefully consider the thickness and quality of the material to provide a proper safety factor.

The last tank I looked at that was close to those dimensions was in San Diego 1" thick at 36" tall (solvent cemented) it had bowing barely perceivable although the tank was about 5 yrs old and was beginning to show signs of crazing along the seams. Unknown whether it will worsen, but I can say with certainty, it will not improve or go away on it's own. Panel deflection (bowing) also leads to distortion and basically puts more wear and tear on the material, along the seams. Despite the density of acrylic, it does saturate and if exposed to too much heat from lighting or room temp combined with the constant force of the internal pressure pusing outwards things slowly change. A similar tank about 30 miles away was made using 1.5 thick material, this tank is also a few years older (ignoring the scratches proportional to the age) you can tell the difference when compairing the two. Perpendicular angles and very little distortion, no crazing or warping.
Strickly a matter of personal preference thats all. Many Mfgs mass produce acrylic boxes that hold water. If you ever get a chance compair the difference in craftsmanship and materials between Stickley and Ikea. Both companies build furniture.

 

[kmu]

Mattfrancis... check out earlier posts in the thread, lots written about it.

KMU...It's too thin for me, just not how I like to build. However...many commercial Mfgs build to those specs all the time. Safe? probably. But personally I build differently and just dont take those chances when considering with the alternatives, (I dont mass produce and build each tank one at at time, I dont build for profit but rather for quality). Heres why. In Japan, we had a lot of seismic activity (will spare the sea stories of 2011) so I carefully consider the thickness and quality of the material to provide a proper safety factor.

The last tank I looked at that was close to those dimensions was in San Diego 1" thick at 36" tall (solvent cemented) it had bowing barely perceivable although the tank was about 5 yrs old and was beginning to show signs of crazing along the seams. Unknown whether it will worsen, but I can say with certainty, it will not improve or go away on it's own. Panel deflection (bowing) also leads to distortion and basically puts more wear and tear on the material, along the seams. Despite the density of acrylic, it does saturate and if exposed to too much heat from lighting or room temp combined with the constant force of the internal pressure pusing outwards things slowly change. A similar tank about 30 miles away was made using 1.5 thick material, this tank is also a few years older (ignoring the scratches proportional to the age) you can tell the difference when compairing the two. Perpendicular angles and very little distortion, no crazing or warping.
Strickly a matter of personal preference thats all. Many Mfgs mass produce acrylic boxes that hold water. If you ever get a chance compair the difference in craftsmanship and materials between Stickley and Ikea. Both companies build furniture.

THX for the advice, will try to get a quote on 1-1/4" acrylic to see if the price difference isn't much

 

[kmu]

On a 72"Lx42"Wx36" made out of 1" acrylic all around which top would you choose and why?

THX in advance

 

[Phixer]

On a 72"Lx42"Wx36" made out of 1" acrylic all around which top would you choose and why?

THX in advance

I would use 1.250" minimum thickness for that height. 1" is too thin for a tank 3ft tall...IMO. Using the same dimensions of 72" long and 42" wide and those cutout dimensions I would use two cutouts (lower illustration). Better structural rigidity and less stress. You would still have enough area for good gas exchange considering a 3ft depth. The top panel behaves differently than the others, it is subjected to compression stress as well being pulled apart. 3 cutouts for a tank 6ft long is greater propensity for cracks and buckling due to less material, not much gained for surface area either vs 2 cutouts with good water movement. I would also radius the inside edges (see photos attached). Im refinishing this tank now (scratch removal). It's 28" tall (inside) using 7/8" thick material ...(strange?) , 30" wide and 120" long. Id like to show you the deflection but it's empty. System is acting up when attempting to open them, hopefully you can open them full size or export them and open with MS Paint.