How to glue a internal overflow box to non-flat acrylic surface

[xeanliao]

Hi,
I am attaching a small internal overflow box to a used 75g acrylic tank, and I just found out that the surface is not fat when the overflow box lays on the surface: about 1/8 inch gap!

It seems not idea to use the watery acrylic glue, do you think so? Do you think I can use heat gun to soften acrylic surface and use clamps to force to eliminate the gap while applying the watery glue? or given it is a small overflow box, perhaps silicone glue would be good enough? Or ???

This is my first time ever working with acrylic and did not think thru enough before getting this used acrylic tank :-(. Please share your thoughts or freely share what you would do.

 

[lapin]

Weld on #16 might work. When dry apply a good second bead as a secondary seal.

 

[theMeat]

Google “amazing goop”. Get marine or plumbers version. Really is amazing how well it works. Have it on my sump for 10 years and still stupid strong

 

[xeanliao]

Google “amazing goop”. Get marine or plumbers version. Really is amazing how well it works. Have it on my sump for 10 years and still stupid strong

It looks promising. Thank you!.
When applying it, would you recommend applying it with or without force to eliminate the gap? wondering if I should use it to "bound" two piece together, or should I use it to "fill" the gap?

 

[theMeat]

It looks promising. Thank you!.
When applying it, would you recommend applying it with or without force to eliminate the gap? wondering if I should use it to "bound" two piece together, or should I use it to "fill" the gap?

It’s pretty thick, you might be able to do both with one application

 

[Augus7us]

Glue the overflow to a flat piece, then glue the flat piece to the tank. Drill through. What I would likely do.