Acrylic fabrication questions? I can help!

[Floyd R Turbo]

IMO you're splitting hairs. Plus I think that it is irrelevant what you put in the tank, the tank should be built to withstand the maximum water column that could be placed in the tank with no other factors, this is how the tank calculators "work". They also do not consider many other relevant factors but those who make these calculators refuse to address these concerns, likely for some liability reasons. Such factors and potential reasons are discussed in this thread if you search it.

Just because there is 2" of sand and then 2" of water on top of it does not mean that the water head is 2" - it is still 4". They hydrostatic pressure of 2" of water above 2" of sand is not very dissimilar to 4" of water with no sand.

The composition of the sand bed or absence of it should be relatively meaningless for our purposes. In the entirety of this thread, this is the first I have heard anyone mention it. Consider the absence of a sand bed and the fact that no one fills their tank full to the brim to be either cancelling each other out of just an additional safety factor, either way it needs not be considered, really.

 

[peppie]

IMO you're splitting hairs. Plus I think that it is irrelevant what you put in the tank, the tank should be built to withstand the maximum water column that could be placed in the tank with no other factors, this is how the tank calculators "work". They also do not consider many other relevant factors but those who make these calculators refuse to address these concerns, likely for some liability reasons. Such factors and potential reasons are discussed in this thread if you search it.

Just because there is 2" of sand and then 2" of water on top of it does not mean that the water head is 2" - it is still 4". They hydrostatic pressure of 2" of water above 2" of sand is not very dissimilar to 4" of water with no sand.

The composition of the sand bed or absence of it should be relatively meaningless for our purposes. In the entirety of this thread, this is the first I have heard anyone mention it. Consider the absence of a sand bed and the fact that no one fills their tank full to the brim to be either cancelling each other out of just an additional safety factor, either way it needs not be considered, really.

I agree, in a nut shell!!

 

[Phixer]

Yes, normally a physics topic. Havent seen it mentioned so decided to. Call it anything you want but the fact still remains. Water volume is affected by the contents inside the tank. And water volume affects water pressure. Water pressure determines thickness.

Actually it does because water volume is less. There is physically less water in the tank because more of it is displaced in relation to the density/mass of the objects placed inside the water column.

Thickness calculators are based on mathematical formulas which support this and the physical properties of the acrylic. These calculations assume all water column. Which is a good conservation on the side of safety. The fact is that the volume of water will be less if displaced by rock or sand. Less water = less pressure and the requirement for thicker material. The block of lead example is a good analogy of this.

To consider this or not? IMHO it's better to be informed by understanding all factors.

 

[solareclisped]

I am wanting to build a ATO storage tank and with the space I have I could make it 20" long, 8" wide and about 20" tall. What type of acrylic do I need to use for this, what thickness and what is best to use for bonding?
Thanks
Gary

 

[Phixer]

I am wanting to build a ATO storage tank and with the space I have I could make it 20" long, 8" wide and about 20" tall. What type of acrylic do I need to use for this, what thickness and what is best to use for bonding?
Thanks
Gary

Will it have a top? Cell cast, solvent cement, web search for aquarium thickness calculator they are all over. Id use 3/8 all around with radiused access cutouts in the top" Gary.

 

[solareclisped]

I was gonna put half a top on it maybe and then just cover the other half. Not certain yet.
http://www.tapplastics.com/product/plastics/cut_to_size_plastic/acrylic_sheets_clear/508
Is that what I would want to use?
Thanks
Gary

 

[peppie]

I was gonna put half a top on it maybe and then just cover the other half. Not certain yet.
http://www.tapplastics.com/product/plastics/cut_to_size_plastic/acrylic_sheets_clear/508
Is that what I would want to use?
Thanks
Gary

Didnt see that your link specified that it was cell cast. You should find some Pexi-G or Polycast for your acrylic. 3/8" will work. You should euro brace the top as stated above.

 

[Floyd R Turbo]

For 20" tall, you might be pushing the limit for 3/8" material, but again this isn't a display tank so you don't care about bowing - but you do care about good seams, so your process must be good to make sure the seams are strong. what you can do is make an interior baffle at the mid point that extends within 1" from top and bottom, this will eliminate the bow and pressure on the seams when the reservoir tank is full.

For this you can use go with cheaper products, stick with a good extruded at the very least, meaning Acrylite FF or Plexiglas MC. For a cheap cell cast, if you can find it, go with Pmax which is sometimes hard to find but it is made by Arkema (Plexiglas parent company) and is sometimes referred to as their "general purpose" material, it is mostly the same as Plex-G but without the print on the mask.

If this is a 1-off project (meaning you don't need extra material laying around) then I would find the name-brand extruded and call it good.

 

[solareclisped]

Thanks for the help. Now for the searching.

 

[solareclisped]

Ok any good suggestions as to where to buy this stuff at?

 

[solareclisped]

I did not realize the expense of acrylic. Maybe I should just do this in glass.

 

[Floyd R Turbo]

Sabic Polymershapes, Laird Plastics, Regal Plastics for whole sheets, many of them will sell you scrap or cut a full sheet into pieces for your needs, or you can go online and have smaller pieces cut custom and delivered but that's $$ and lots of times you get whatever they have, which may be total cr-p.

Glass, that's a whole nother topic.

 

[GrampaDon]

edge preping ?

edge preping ?

Exactly how is it done. Sounds like a simple question right.?
I hear all the time use a router. Well I have one and 2 flush cut bits too.
Since I dont do acrylic much I made a DIY router table and a fence. Which just left a series of ridges along the edge.

Well I saw a photo of James using one but different than I thought.
He used it like a saw with the fence far away from the piece.
Where I assumed the how was like making molding. With the fence over the bit and just enough bit showing to work the edge in a profile.

So will someone put a picture up of the correct method. ?

I want to get better at this and could use help.

 

[solareclisped]

Would the acrylic from glass cages .com be ok to use? So far they are the cheapest I have found already cut to size?

 

[dattack]

The cheapest acrylic would probably be your local acrylic distributor. Best to buy a sheet and have it cut to your specs.

 

[Sulcata102]

does anyone know a good book to read, or a good internet net source, that covers, in depth, acrylic tank building? Not including this forum.

 

[peppie]

does anyone know a good book to read, or a good internet net source, that covers, in depth, acrylic tank building? Not including this forum.

There are none

 

[Floyd R Turbo]

This thread is the best and probably only internet source of acrylic fabrication for aquariums.

 

[Kurkis493]

I am trying to go through this entire thread start to finish but it is long. I plan to do this however and I am sure somewhere in this storybook my question has been answered.

Someone please humor me.

If I wanted to make a 24x24x24" rimless cube from acrylic, can I do it with 1/2" or is that an awful idea? If I want rimless, what should I be considering?

My next question, I am wanting to match a sump to this which would be ruffly 22x22x16...

Can I use 3/8 or should I use 1/2"? Between the baffles and the duo filter sock holder acting as a brace I assume I can use a little thinner material...

I don't want bowing - MP10s hold on max 1/2" and that is what I plan to use on this system....

I would be ordering Polycast.

Thanks!

 

[peppie]

I am trying to go through this entire thread start to finish but it is long. I plan to do this however and I am sure somewhere in this storybook my question has been answered.

Someone please humor me.

If I wanted to make a 24x24x24" rimless cube from acrylic, can I do it with 1/2" or is that an awful idea? If I want rimless, what should I be considering?

My next question, I am wanting to match a sump to this which would be ruffly 22x22x16...

Can I use 3/8 or should I use 1/2"? Between the baffles and the duo filter sock holder acting as a brace I assume I can use a little thinner material...

I don't want bowing - MP10s hold on max 1/2" and that is what I plan to use on this system....

I would be ordering Polycast.

Thanks!

You could build your rimless 2' cube using 3/4''. If you dont want any bow you will need to use 1''.
If you are bound to the 1/2'' material cause of the MP 10s you will need to use a top euro-brace.
As for the sump you can use the 3/8'' as long as the baffles are place at least 1/3rd division of the tank.
Polycast is good.