Bracing for rimless 65g Tank?

Glasswalker · Mar 28, 2016

Hey, so I'm new to the hobby/site, I've got another thread documenting my first tank build here:
https://www.reef2reef.com/threads/first-build-some-questions-and-documenting-my-build.241255

I just got my new (used) tank home, and am wondering if I should add any bracing to it. So thought I'd toss the question up here for evaluation.

Here is the specific post in my build thread that has a pic of the tank close-up in my garage:
https://www.reef2reef.com/threads/f...and-documenting-my-build.241255/#post-2830827

Now for the story on the tank:

Dimensions are 16" wide x 47" long x 20" deep which equates to a 65 gallon tank.
It's a custom tank, which was made in the 80s by an avid fish keeper (freshwater). Who has over 10 tanks, and at one time owned an LFS. It was apparently carefully maintained up until he passed away in the fall. His son was selling off all his gear (how I acquired it). The Son did not know any of the specifications or other details. Other than it was custom made, and it's approximate age, he doesn't know any technical specifics of the tank (for example is it tempered?). I plan on trying to use the polarized glasses method to determine if it's tempered shortly.
He did tell me it was full and in use right up until about 30 days ago, and never had any bowing at all. He was trying to keep up his father's hobby, but didn't have the time to continue maintaining it.
The seams look very clean, silicone cleanly applied, very even, and still retains it's elasticity, no cracks or discoloration or anything.
Glass is 10mm thick EXACTLY (checked it in about 10 spots with digital calipers, it's 10.00mm exactly in all samples but one which was 10.01mm lol) so it's slightly thicker glass than 3/8" (which is about 9.5mm)
Glass is polished/bevelled on the top edge. Has about a 2-3mm bevel on it.

So my question is should I add any kind of bracing to it before starting my reef build? If so, does DIY Eurobracing work? And if so what kind of brace thickness should I go with?

I'd like to avoid bracing if it's not needed, but I don't want to "cheap out" and end up with a catastrophe.

Thoughts/suggestions?

Thanks!

Glasswalker · Mar 31, 2016

So just an update, I've fully washed down the tank at this point, and filled it with water. Pics in my main thread here:
https://www.reef2reef.com/threads/first-build-some-questions-and-documenting-my-build.241255

Another pic I'll repost here is one I took looking along the front pane of glass on the edge (looking for bowing from the water weight).

As you can see there is almost no perceptible bowing (I used a long straight edge, and found it to be a total of approximately 1mm maximum deflection at the center point)

So what's everyone's opinion. I'm not concerned about the look of the bowing, as I said unless you're doing this look down the edge, you totally can't see that it's bowed at all. 1mm across a 4' length doesn't sound like much to me.

But do I need to brace it to be safe? Thoughts?