Tiny leak through Shadow overflow gasket area

[FishPersonFL]

I am testing for leaks right now in my new plumbing set up. There is the tiniest of leaks through the entrance to the external box. I have a gasket on each side of the glass. The 'washer'/big plastic nut to hold the box in place was pretty tight when leak noticed. I tightened it more which reduced it. It's about max tighness, which i'm nervous can damage the box or the glass of the tank (?). I'm sure someone has experience this before. Im' glad I used unions, so I can detach the shadow. What should I know and do to fix this? Silicone grease??? get new gaskets? they are new. and I have others with an 'extra' shadow overflow. The hole drilled in tank looked perfect. I'll likely see it again as I need to fix this. Maybe i'm lucky this seems to be the only leak in my first ever piping project (?)

TIA!

 

[FishPersonFL]

I see others have had leaks with shadow. But my problem may be that the bak of my tank has a black film on it. I bet that's it. I'm 90% sure I can cut it with a sharp blade. I'll cut aroudn the drill holes so the gaskets have only clean glass. I was also reading that others used other brand gaskets that solved their leaks.
*How do you unscrew a very tight washer/nut on this? I may have tightened it too much that I cant lossen it . There is little room to get your hand in the box to get the best grip as well. I was going to try to find online a rubber pad used to open glass jar lids lol. Amazon product

 

[John Bolden]

Can be a pinched seal try unscrewing and check seal.

 

[John Bolden]

I see others have had leaks with shadow. But my problem may be that the bak of my tank has a black film on it. I bet that's it. I'm 90% sure I can cut it with a sharp blade. I'll cut aroudn the drill holes so the gaskets have only clean glass. I was also reading that others used other brand gaskets that solved their leaks.
*How do you unscrew a very tight washer/nut on this? I may have tightened it too much that I cant lossen it . There is little room to get your hand in the box to get the best grip as well. I was going to try to find online a rubber pad used to open glass jar lids lol. Amazon product

If it is a pinched seal you most likely damaged it and will have to get a replacement. Try channel locks with a towel around the nut to not damage the plastic.

 

[FishPersonFL]

If it is a pinched seal you most likely damaged it and will have to get a replacement. Try channel locks with a towel around the nut to not damage the plastic.

I have extra shadow brand gaskets... The nuts have nothing for a wrench to grip is nearly smooth and round, with some very shallow indentions. If i need to then I'll carefully break the nuts off. I have spare set of those as well.
**Could it be the black film that's causing the leak?

 

[John Bolden]

I have extra shadow brand gaskets... The nuts have nothing for a wrench to grip is nearly smooth and round, with some very shallow indentions. If i need to then I'll carefully break the nuts off. I have spare set of those as well.
**Could it be the black film that's causing the leak?

1. Send a picture so I can visualize.

2. The towel and the channel locks will grip on to it. They look like this

Channellock 10 in. Tongue and Groove Plier 430 - The Home Depot

The Channellock 10 in. Straight Jaw Tongue and Groove Pliers are constructed with high-carbon steel and fashioned with laser heat-treated teeth for strong, nonslip jaw action. Undercut tongue-and-groove

www.homedepot.com

 

[FishPersonFL]

1. Send a picture so I can visualize.

2. The towel and the channel locks will grip on to it. They look like this

Channellock 10 in. Tongue and Groove Plier 430 - The Home Depot

The Channellock 10 in. Straight Jaw Tongue and Groove Pliers are constructed with high-carbon steel and fashioned with laser heat-treated teeth for strong, nonslip jaw action. Undercut tongue-and-groove

www.homedepot.com

I missed you said to use a towel. That might help with grip also. Heres pic.
what abiut the black film on back of tank?
Ty

 

[John Bolden]

I missed you said to use a towel. That might help with grip also. Heres pic.
what abiut the black film on back of tank?
Ty

Try to take it off because either way you need to take it off to 1. fix the seal 2. cut the black vinyl off.

 

[FishPersonFL]

Try to take it off because either way you need to take it off to 1. fix the seal 2. cut the black vinyl off.

Thank you!! Ill do this tomorrow after making sire no other leaks. Im thiniking the nut cant be made too tight since there is little grip on to it to actually overtigjhten it.