Removing plastic centre brace on my 45 gallon tank

[apepper]

I have a 45 gallon tank (36Lx12Dx24H) that has a plastic centre brace. I want to remove the brace to eliminate the shadowing (I don't want to get a second MH light). I have seen a modification described on reef central where the plastic brace was replaced by a clear acrylic brace.

(http://www.reefcentral.com/forums/showthread.php?s=edb0e60d9663e068d76814fc71ab04ea&threadid=289473 ).

As Steve pointed out in another thread the MH may heat the acrylic enough to cause it to weaken and stretch (could also happen to the existing plastic brace) so this is probably a flawed approach.

Since I will not be buying a new tank right now I have two choices:

1) Install glass euro-bracing along the edges, but this may interfere with my HOB skimmer.

2) Install a glass cross brace. What size joint will provide enough strength under tension?

Any thoughts?

[Aquattro]

What thickness is the glass?

[apepper]

I'll check when I get home. Any idea how thick the glass should be before a brace is uneccessary on this size tank? I guess I have some research to do on material strength of glass.

[Aquattro]

I believe 7/16" is enough to go without the brace. Maybe Steve can pop in an opinion, as he removed the brace from his 3' long, 2' high tank. My 75g had no brace with that thickness, but it was also 18" high.

[StirCrazy]

get an accurate measur of the thickness of your glass, my glass is 3/8" thick and it is fine but I would recomend doing it with a empty tank and filling it with fresh water to measure the bow.

is there any tension on your plastic center brace?

Steve

[apepper]

The glass thickness is 5/16". It doesn't take much pressure to cause the top edges to deflect and put tension on the plastic centre brace. The tank is currently empty so now is the time to make any modifications. What thickness glass would you use to make a cross brace 3/8 or 7/16 (or thicker)? One brace or two?

[StirCrazy]

I would make your cross brace out of 1/2" glass and make it about 4" wide.

Steve

[apepper]

Ok thanks Steve. I was originally thinking thinner and wider (3/8x6") for about the same contact area but the thicker glass would provide more impact resistance which is good. 0.5x4" gives me 2 square inches of surface area which should be able to hold about 900lbs of force using GE 1200 silicone...that should give me a healthy margin for error ;)

[wayner]

I did exactly that 2 years ago, cut out plastic brace on a 65 gallon aga, replaced it with a glass brace, I did it mainly because I heard over time the plastic brace would become brittle due to the heat from the Halides.

Just siliconed the glass brace right in place where the plastic one was.


It worked out great, no issues.


Exactly what steve said is what I did, half inch by 4" wide.

[apepper]

Does anyone know where to find GE 1200 silicone in the Victoria area (tried HD and Cnd Tire), or can someone recommend an alternative high tensile strength silicone?

[Aquattro]

Does anyone know where to find GE 1200 silicone in the Victoria area (tried HD and Cnd Tire), or can someone recommend an alternative high tensile strength silicone?

I have some here. You can have a bit to glue your brace in. BTW, it's black, in case it matters.

[StirCrazy]

is that stuff ge1200 Brad?

Steve

[Aquattro]

is that stuff ge1200 Brad?

Steve

Ya, I got it from Wayne at Seastar

[StirCrazy]

ok I thought it wasn't marked.

Steve

[apepper]

Hey, thanks for the offer Brad, black silicone will be fine. I will pm you.

Alex

[apepper]

This is a picture of the finished brace. Thanks again for the silicone brad.

http://www.canreef.com/photopost/data/500/827TankBrace.JPG?9700