Not another tank trim removal question!

Tom@HaslettMI · Feb 26, 2014

OK so I know this question has been asked many times, and I know the answer is (almost) always "no". But I think this one might be different.

I am going to be building a sump out of a 30 gallon breeder (36"x18"x12"), and am contemplating taking the top trim off. The water level will run at about 9" and there will be 3 baffles that span front to back.

So, what's the consensus? Is this one of the rare "yeses" to this question?

Thanks,
Tom

bct15 · Feb 26, 2014

Don't do it, your baffles might help a little but don't do it.

xthunderx · Feb 26, 2014

I personally wouldn't risk it, I realize it's just a sump and the level won't be that high. But a leak is a leak and ultimately it's all plumbed together. I say no.

Mike J. · Feb 26, 2014

No, and I'll give you a reason. Rimless tanks are made differently to hold the panels together. Tanks with trim are made to depend on the trim.

Tom@HaslettMI · Feb 26, 2014

So, everyone is in favor I see! Just kidding.

@Mike J. - Do rimless tanks use a different silicone/sealant? Not doubting, just looking to learn.

Thanks for the replies.

Tom

Fin · Feb 26, 2014

No guts no glory. If you will have baffles siliconed in place, you should have no issues with bowing. It is just a sump. I would do it if I wanted the trim off of it. I would use Momentive RTV-103 (black) or 108(clear) to attach the baffles. I get mine from Amazon.

wangspeed · Feb 26, 2014

Fin said:
No guts no glory. If you will have baffles siliconed in place, you should have no issues with bowing. It is just a sump. I would do it if I wanted the trim off of it. I would use Momentive RTV-103 (black) or 108(clear) to attach the baffles. I get mine from Amazon.

Only a sump? If it leaks, it isn't just the sump that leaks.

Fin · Feb 26, 2014

Why would it leak? Take the trim off, install the baffles and do a leak test. If it doesn't leak, it doesn't leak.

KorL · Feb 27, 2014

There. You got your "yes" answers that you were waiting for. Go ahead and give a try

I think it will be ok. Especially if you're going to be adding baffles and not filling the tank to the top. At least go with a thicker acrylic or glass for the baffles for extra insurance

TriggerThis · Feb 27, 2014

I think with the baffles you will have no issues with just removing the top trim.
But on the same note WHY is a great question.
What would a rim on the sump matter. Any equipment that was on my sump that wouldn't fit over the trim I just notched a bit of it and everything fit fine.
Why risk it just for "sump aesthetics"

bct15 · Feb 27, 2014

Tom@HaslettMI said:
So, everyone is in favor I see! Just kidding.

@Mike J. - Do rimless tanks use a different silicone/sealant? Not doubting, just looking to learn.

Thanks for the replies.

Tom

Rimless tanks are designed with thicker glass, which allows for more bonding area at the seams.

Mike J. · Feb 27, 2014

bct15 said:
Rimless tanks are designed with thicker glass, which allows for more bonding area at the seams.

They are also bonded between the glass panels with thicker silicone. The framed tanks have very little silicone between the edges and rely on the bead of caulk on the outside of the seam.

Tom@HaslettMI · Feb 27, 2014

Fin said:
No guts no glory. If you will have baffles siliconed in place, you should have no issues with bowing. It is just a sump. I would do it if I wanted the trim off of it. I would use Momentive RTV-103 (black) or 108(clear) to attach the baffles. I get mine from Amazon.

I like your attitude! Thank you for the silicone recommendation.

KorL said:
There. You got your "yes" answers that you were waiting for. Go ahead and give a try

I think it will be ok. Especially if you're going to be adding baffles and not filling the tank to the top. At least go with a thicker acrylic or glass for the baffles for extra insurance

Looks like I got two "yes" answers... As for the baffles I am going to use .25 inch (6mm) starboard, which is thicker than the glass I would use. Does that influence anyone else's thoughts on doing this?

TriggerThis said:
I think with the baffles you will have no issues with just removing the top trim.
But on the same note WHY is a great question.
What would a rim on the sump matter. Any equipment that was on my sump that wouldn't fit over the trim I just notched a bit of it and everything fit fine.
Why risk it just for "sump aesthetics"

Why is an excellent question. My answer is two fold. First, my stand is open so aesthetics is part of it. Second, and more importantly, I like to DIY and try new things with my reef tank. A few examples: I've built my own Wavebox, canopy, stand, overflow, full spectrum LEDs, and LED refugium light. And as stated above am going to use starboard for the sump baffles.

bct15 said:
Rimless tanks are designed with thicker glass, which allows for more bonding area at the seams.

That makes sense. But using that logic, wouldn't adding multiple baffles provide more bonding strength than a few extra millimeters of silicone on the corners?

Thank you everyone for the input. I'm still not sure if I will do this or not... so keep the posts coming! Ideally I would like to find an online tool that could provide a hard number as to whether this is doable. Something that takes the bonding strength of silicone, water height, glass thickness, water pressure, ect. and calculates if this will hold. Anyone know of such a site/resource?

Thanks,
Tom

Tom@HaslettMI · Feb 27, 2014

Mike J. said:
They are also bonded between the glass panels with thicker silicone. The framed tanks have very little silicone between the edges and rely on the bead of caulk on the outside of the seam.

So, the seams are the weak point? I was always under the impression that the concern was with the front and back panels bowing due to water pressure. If the seams are the issue then that makes me less inclined to remove the trim.

Thanks for the info,
Tom

Fin · Feb 27, 2014

The thicker glass on rimless tanks is to prevent deflection in the glass. This allows for less, if any bracing. Some are still "Euro-Braced" along the bottom to add strength.

I think you will like the Momentive RTV sealant. I recently built a large sump from scratch, using the RTV 103. I decided to go a different direction and scrapped that sump. I later tried to remove parts of it for re-use and it was not fun cutting those parts out.

I prefer using glass baffles in my sump. If you are not handy cutting glass, have your local glass shop cut them to size, using 1/4" plate glass. Remember to leave a little room for sealant in between the edge of the baffles and the sump wall. You don't want glass on glass.

I would also suggest taping off the area where you will be using silicone. Apply the sealant, smooth it out and remove the tape immediately. Leaves a nice sharp edge and keeps trimming and clean-up to a minimum. I just use regular painters tape.

Bad Company · Feb 27, 2014

Water pressure is a function of the water depth X the area of the glass it is pushing on. If you are truely only filling you sump half way, the water pressure on the glass will be much less than if the tank were full. Be aware though, when my return pump shuts off, my sump fills almost to the brim! This depends on how much your overflow holds, as well as the extra maintained above the bottom of the overflow teeth by the return pump's flow. Should you have a sump failure, will the stand hold all the water? If not... I would be leery about messing with the manufacturer's designs. You WILL bump the sump walls some time. Your sump WILL fill up at some point. Water damage is really nasty.

dvskin · Feb 27, 2014

You won't have structural problems. The tank is short enough, but you will be cutting your arm up every time you reach into the sump. The glass under the rim is very raw, n not sanded at all. Found out the hard way on my 20L

Tom@HaslettMI · Feb 27, 2014

dvskin said:
You won't have structural problems. The tank is short enough, but you will be cutting your arm up every time you reach into the sump. The glass under the rim is very raw, n not sanded at all. Found out the hard way on my 20L

Good point. I was planning to sand/smooth the exposed edges. I believe a fine grit sandpaper will do the trick. Can anyone confirm that or offer a better technique?

Tom