Reef Central Online Community
Marine Depot

Home Forum Here you can view your subscribed threads, work with private messages and edit your profile and preferences View New Posts View Today's Posts

Find other members Frequently Asked Questions Search Reefkeeping ...an online magazine for marine aquarists Support our sponsors and mention Reef Central

Go Back   Reef Central Online Community > General Interest Forums > Do It Yourself
Register Blogs FAQ Calendar Mark Forums Read

Notices

User Tag List

Reply
Thread Tools
Old 02/24/2020, 08:43 PM   #1
Jade5051
That guy...
 
Join Date: Nov 2004
Location: Illinois
Posts: 1,217
Glass bottom safety factor

Can someone please help me or point me in the right direction? I'm trying to calculate the thickness for a 3.8 safety factor on the bottom of a 28x28x17 aquarium. I'm using 0.5" glass for the sides and need to cut a 28x28 bottom but I don't know how thick the bottom needs to be. I've been looking on the interweb for over an hour now.


__________________
The dream that is now a memory - http://reefcentral.com/forums/showthread.php?t=2550891
Jade5051 is offline   Reply With Quote
Old 02/24/2020, 08:52 PM   #2
Jade5051
That guy...
 
Join Date: Nov 2004
Location: Illinois
Posts: 1,217
Finally found a calculator that says 8.5mm which would be 3/8" glass. I'd like to not have 55 gallons of water on the floor could anyone please reply? Does that sound right? I was going to do rimless if that makes a difference.


__________________
The dream that is now a memory - http://reefcentral.com/forums/showthread.php?t=2550891
Jade5051 is offline   Reply With Quote
Old 02/25/2020, 07:46 AM   #3
mcgyvr
Registered Member
 
mcgyvr's Avatar
 
Join Date: Sep 2003
Location: North Carolina
Posts: 20,050
@Jade5051
The answer depends on how the bottom is supported..


__________________
Who me?
mcgyvr is offline   Reply With Quote
Old 02/26/2020, 07:40 AM   #4
lapin
Registered Member
 
lapin's Avatar
 
Join Date: Aug 2017
Location: Austin
Posts: 793
When in doubt and not being a seasoned builder I would error on the side of thicker.

Disclaimer:
Most of my glass tank experience is with the old metaframe slate bottom tanks.


__________________
Tank sizes, 2-10's a 55 and one that's about 500gal

Current Tank Info: Interior decorating happening
lapin is offline   Reply With Quote
Old 02/27/2020, 11:43 AM   #5
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,726
Quote:
Originally Posted by Jade5051 View Post
Finally found a calculator that says 8.5mm which would be 3/8" glass. I'd like to not have 55 gallons of water on the floor could anyone please reply? Does that sound right? I was going to do rimless if that makes a difference.
3/8 = .375 = 9.5mm approx.
Should be thick enough..

Calc I play w/ given your dimensions (17 is DEPTH right) would give 3/8" bottom a safety factor of 4.8...


side glass needs to be only 6.4mm...283" thick.

If you actually go 1/2 sides just do 1/2 bottom..
Or all 3/8" glass.

l and width can't be equal thus the discrepancy ..and also rounded a bit.




oreo57 is offline   Reply With Quote
Old 02/27/2020, 01:25 PM   #6
mcgyvr
Registered Member
 
mcgyvr's Avatar
 
Join Date: Sep 2003
Location: North Carolina
Posts: 20,050
You want more than a 3.8 safety factor on a rimless tank..
Often they use near double (7-7.6) or more for rimless..


__________________
Who me?
mcgyvr is offline   Reply With Quote
Old 02/27/2020, 02:40 PM   #7
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,726
Quote:
Originally Posted by mcgyvr View Post
You want more than a 3.8 safety factor on a rimless tank..
Often they use near double (7-7.6) or more for rimless..

AFAICT those calcs assume "free standing" i.e rimless..
1/2 thick glass bottom on a 50gal tank..for a factor of 7+ btw.

Quote:
The calculator calculates the bending of a glass pane with the forces that would be exerted by water on the pane if it was freestanding (supported on 4 corners, but not fixed).
https://www.marineaquariumsa.com/thr...ss-tank.48280/


Calc maker..and good discussion..


I have no problems w/ "overbuilding" anything..and would rarely settle for "minimum" thickness but don't see 3.6 as minimum..

You could check w/ Glasscages to see their glass thickness. They have a close tank size:

Quote:
40 Square (Rimless) 24 x 24 x 16 tall




Last edited by oreo57; 02/27/2020 at 02:48 PM.
oreo57 is offline   Reply With Quote
Old 03/04/2020, 10:47 PM   #8
Jade5051
That guy...
 
Join Date: Nov 2004
Location: Illinois
Posts: 1,217
The reason I'm using 1/2" glass for the sides is because it's scrap glass from another tank that broke. I just need a bottom and I have a tank.


__________________
The dream that is now a memory - http://reefcentral.com/forums/showthread.php?t=2550891
Jade5051 is offline   Reply With Quote
Old 03/05/2020, 09:27 AM   #9
oreo57
Registered Member
 
Join Date: Apr 2013
Posts: 1,726
Quote:
Originally Posted by Jade5051 View Post
The reason I'm using 1/2" glass for the sides is because it's scrap glass from another tank that broke. I just need a bottom and I have a tank.
I get stuck in my head...

Using thinner glass for the bottom (regardless of safety factor) is just psychologically unacceptable..

14.8 (sides) and 8.5 (bottom) safety factors for 1/2 all around..

1/4" (6mm) ..nope
5/16" (8mm) It is not common in US. nope..
3/8" (10mm) pick one
1/2" (12mm) pick one


oreo57 is offline   Reply With Quote
Old 03/10/2020, 01:39 AM   #10
H2oGarden
Registered Member
 
Join Date: Sep 2013
Posts: 52
3/8 if supported, 1/2 if not supported.


H2oGarden is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -6. The time now is 07:28 AM.


TapaTalk Enabled

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2020 Axivo Inc.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef CentralTM Reef Central, LLC. Copyright 1999-2014
User Alert System provided by Advanced User Tagging v3.3.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.