need advice on bonding an acrylic sump lid to an acrylic sump

[salt_water_aqua]

I am in the process of setting up a 500 gallon sw aquarium. During my wet test, I cut off the power to simulate a power outage. As expected the water level dropped below the overflows in the aquarium and the level in the acrylic sump (72"L x 22"W x 20"H )went up to approx. 2 inches from the top. Unexpectedly, it was noticed that the acrylic sump lid separated from the long sides on both the front and back in the middle portion of the sump. There was bowing on both sides such that the max separation was around 1/2 of a pinky finger in the middle of both walls front and back. The end wall portions along this length remained intact with no separation. Thus each wall has approximately one 3rd length still intact and two 3rd's length has gradual separation starting near the ends and max'ing out in the middle. It is to be noted that upon sump drain down, the walls relaxed and came back together. No leaks occurred during the scenario. The sump manufacturer is sending me something to bond it back together.

I had to make special provisions to put this 72"L x 22"W x 20"H sump in the steel stand and replacing it is not a practical option. I strongly desire to repair it. Does anyone have any experience with acrylic glues/bonding and techniques. Any advice would be most appreciated.

[medic29]

I would think you are going to need to remove this to repair it properly. I would think the acrylic solvent is going to need to be applied on/from the inside; at least this is how I would perform the repair.

Others with more expertise may jump in, but this is what I'm thinking.

[Acrylics]

I tend to agree, it should be removed to be repaired properly.
If this is absolutely not possible, you may be able to squeeze some solvent in there. Weld-on 40 or 16 may be a suitable candidate as well. You may wish to smear some on a gusset and simply smush the gusset into place to reinforce the affected area. Won't be pretty or perfect but more effective than nothing.

HTH,
James