4’x8’x4’ plywood tank

[jonathanM]

Hey guys I’m new here so if this has been asked and answered to death I’m sorry lol. I’m building a plywood tank and planning on using a 4x8 3/4 thick sheet of acrylic, do I need to use a center beam support or is the acrylic strong enough to span that width? Thanks for any help or suggestions

 

[LukeOscar]

Hey guys I’m new here so if this has been asked and answered to death I’m sorry lol. I’m building a plywood tank and planning on using a 4x8 3/4 thick sheet of acrylic, do I need to use a center beam support or is the acrylic strong enough to span that width? Thanks for any help or suggestions

most plywood tanks will have it setup like an actual window. so you have plywood lining the top and bottom of the acrylic sheet. needing a brace will depend on how strong you build the actual structure. 4ft depth is pushing it for 3/4" in my opinion.

 

[jonathanM]

most plywood tanks will have it setup like an actual window. so you have plywood lining the top and bottom of the acrylic sheet. needing a brace will depend on how strong you build the actual structure. 4ft depth is pushing it for 3/4" in my opinion.

Thanks for the quick response I I’ll put a center beam in just be be safe

 

[wednesday13]

Thanks for the quick response I I’ll put a center beam in just be be safe

Bare minimum for 4’ height would be 1” acrylic. Even then only a 4’x4’ span would support that height. Ud need a center support on the front of the tank to prevent the bowing by making 2 windows on an 8’ span. 36” for 3/4” acrylic would be a better choice here. Thats about the max for 3/4” is 36” tall, even then 30”-32” is safer for 3/4” height. I used 3/4” on a 30” height diy build 8’ span.

 

[LukeOscar]

Bare minimum for 4’ height would be 1” acrylic. Even then only a 4’x4’ span would support that height. Ud need a center support on the front of the tank to prevent the bowing by making 2 windows on an 8’ span. 36” for 3/4” acrylic would be a better choice here. Thats about the max for 3/4” is 36” tall, even then 30”-32” is safer for 3/4” height. I used 3/4” on a 30” height diy build 8’ span.

yea i would advise he cut that 4x8 sheet to 3x8. only way i would run the 3/4" at 4ft is if i bolted the entire pannel to the plywood tank.

 

[jonathanM]

Thanks again for all the help, so far I have the bottom and one wall built I could still drop it down to 3’ but would like to keep it at 4 if possible. The frame is a double studded wall made with 2x4s and they are all glued and screwed together with metal brackets. It’s 4x8 foot outside diameter so the plywood and acrylic will have a solid frame to rest against. I will get some pictures after work today and try to document the build

 

[LukeOscar]

Thanks again for all the help, so far I have the bottom and one wall built I could still drop it down to 3’ but would like to keep it at 4 if possible. The frame is a double studded wall made with 2x4s and they are all glued and screwed together with metal brackets. It’s 4x8 foot outside diameter so the plywood and acrylic will have a solid frame to rest against. I will get some pictures after work today and try to document the build

you dont have to make the entiire tank 36" just the viewing pannel itself.

 

[jonathanM]

you dont have to make the entiire tank 36" just the viewing pannel itself.

Yeah true if I go with 1” do you think it will be ok with a center beam? Plus the bottom and top will have a tripled 2x4 to rest against and the two sides will have a 6” wall. So it won’t be a true 4x8 view panel it will be shorter