Overflow box hairline crack sealing

[cec009]

Hi,

I I have these small hairline cracks on internal overflow box.
I filled the back of the box and it does leak very slowly into the display tank.
What's the best way/product to seal these cracks and make it look decent?
I was thinking either some 2 part epoxy or super glue. Maybe silicone but I feel its a bit harder to make it look clean.

Thanks

 

[cec009]

Not sure if super glue, 2 part epoxy, or silicone ( or combination of the 3) would be best suited for this

 

[Dreminon]

I would not worry about them unless they where leaking into a dry area or above the drain line. Some of the new add on to turn a tank into a AIO have small gap all the way around the box that is held to the wall with magnets.

 

[Dreminon]

Oh and Welcome to the Salty Crew. just noticed was your first post.

 

[littlebigreef]

Depending on the plastic type Weldon is another option, it comes in different thicknesses. If it’s internal and you’re using stand pipes/silent over flow assembly I wouldn’t worry.

 

[cec009]

Thanks! It is an internal overflow. I guess my concern is a pump failure and having the display tank leak into the box and flooding over the sump. My sump can handle if water simply drained to the weir height but not all the way to the herbie main drain several inches below.

 

[Dreminon]

Thanks! It is an internal overflow. I guess my concern is a pump failure and having the display tank leak into the box and flooding over the sump. My sump can handle if water simply drained to the weir height but not all the way to the herbie main drain several inches below.

no matter if the cracks are there or not if you lose power the water will drain all the way to shortest drain. So may need to increase size of sump if it can not handle it.

 

[cec009]

no matter if the cracks are there or not if you lose power the water will drain all the way to shortest drain. So may need to increase size of sump if it can not handle it.

If the internal overflow box is completely sealed wouldn't the display tank just drain to the height of the weir and the water inside the overflow box only drain to the shortest drain? The sump can handle it in this situation but not if the entire display tank also drains to the height of the shortest drain (which would be something like ~30 gallons out of the 100 gallon display tank.

 

[Dreminon]

no it would drain to lowest drain. let me put it this way do you think water can just sit on top of a hole and not go down it? nope its going to take the path of least resistance that being the pipe down to the sump. sorry.

 

[Dreminon]

If the internal overflow box is completely sealed wouldn't the display tank just drain to the height of the weir and the water inside the overflow box only drain to the shortest drain? The sump can handle it in this situation but not if the entire display tank also drains to the height of the shortest drain (which would be something like ~30 gallons out of the 100 gallon display tank.

ok yes it will drain to weir but also the water in over flow box will drain to the lowest drain. sorry if im not explaining it right

 

[cec009]

ok yes it will drain to weir but also the water in over flow box will drain to the lowest drain. sorry if im not explaining it right

Yes ok I think we are thinking the same thing then. If the pump stops and the display tank drains to the weir + the water in the overflow box drains to the lowest pipe, my sump can handle it.
But if the display tank is leaking into the overflow box through these hairline cracks, eventually the display tank will also drain to the lowest drain inside the box which would be too much water for my sump, which is why I need to seal these hairline cracks.

I think I'm going to try using super glue first on the cracks to see if it seals the water in the box. Just not sure if super glue will hold up to that pressure. Its a 100 gallon display tank with a 40 gallon sump, but the sump will probably only hold ~25 gallons.

 

[Dreminon]

is the cracks above or below lowest drain?

 

[cec009]

there are cracks both above and below the lowest drain in the overflow.
I may use flex seal to patch them up.

 

[littlebigreef]

@cec009 A product like weld-on fuses the plastic as opposed to a product that just adheres. You’d just need to double check the materials. On the other hand super glue might get the job done.

 

[cec009]

@cec009 A product like weld-on fuses the plastic as opposed to a product that just adheres. You’d just need to double check the materials. On the other hand super glue might get the job done.

I see, I've never used weld-on but I am looking for a solution that would be more durable without making the box look like a mess. Do you think weld-on would be better than super glue. My concern is super glue may not hold under the water pressure long term.

 

[littlebigreef]

I see, I've never used weld-on but I am looking for a solution that would be more durable without making the box look like a mess. Do you think weld-on would be better than super glue. My concern is super glue may not hold under the water pressure long term.

Happen to know the tank manufacturer? I did a Google search but I’m not finding what plastic internal overflows are of. I’ve used it to build acrylic boxes, fix sumps and replaced overflow ‘knock out’ covers in the past.

It fuses a few kinds of plastic and the thinner viscosities can really get into cracks. Attaching the label of the bottle I have on hand.

 

[cec009]

Happen to know the tank manufacturer? I did a Google search but I’m not finding what plastic internal overflows are of. I’ve used it to build acrylic boxes, fix sumps and replaced overflow ‘knock out’ covers in the past.

It fuses a few kinds of plastic and the thinner viscosities can really get into cracks. Attaching the label of the bottle I have on hand.

The tank maker is CAD Lights. The model is 100 gal Artisan 2. To patch the cracks would you suggest the thinner Weldon 3/4 or 16?
I read also that weld on might make the cracks worse? https://www.nano-reef.com/forums/topic/90290-fixing-cracked-acrylic/

Thanks!

 

[littlebigreef]

The tank maker is CAD Lights. The model is 100 gal Artisan 2. To patch the cracks would you suggest the thinner Weldon 3/4 or 16?
I read also that weld on might make the cracks worse? https://www.nano-reef.com/forums/topic/90290-fixing-cracked-acrylic/

Thanks!

I read the thread. Seems to suggest that it’s just not solving the underlaying issue of why the cracks started in the first place.

I’ve always used 16 (or a thicker one).

Worth point that article is about an acrylic tank. Still need to make sure it’s able to the type of plastic your overflows are made of.

 

[cec009]

I read the thread. Seems to suggest that it’s just not solving the underlaying issue of why the cracks started in the first place.

I’ve always used 16 (or a thicker one).

Worth point that article is about an acrylic tank. Still need to make sure it’s able to the type of plastic your overflows are made of.

I'm not sure how to tell what type of plastic the overflow is made of. I'm thinking its acrylic but not 100% sure. Maybe flex seal would be enough to do the job...plus it seems easier to get than weld on.

 

[RealFish]

I would first try a thin bodied Weldon product. I've never fixed an overflow, but I've built a small sump before and the capillary action will pull the Weldon into the open space as long as it's not too large.

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.tapplastics.com/image/pdf/PB-IPS2354.pdf