The1and only;3633531; said:
Are you going to double up the 2x4 frame at all? It seems like alot of pressure on the frame.
If you mean the insert that the acrylic sets against, no. It's actually a 2x4 and 1x4 together. The 2x4 is glued and screwed to the 2x6 next to it. There's at least a 1/2 lb. of 3" deck screws in there.
The heavy duty liquid nails construction adhesive forms a bond that would likely hold even if the deck screws weren't in there. The Dow 795 that will be sealing the window bonds extremely well to wood, so the sheer strength of frame is extremely strong.
The greatest pressure is at the bottom of the tank then moving upward it lessens, so the most critical point is the bottom of the acrylic contrary to popular belief thinking the top is.
The entire forward thrust of the acrylic is distributed over almost 300 linear inches of surface on the 2x4/1x4 frame. Every deck screw would have to fail in addition to the bond between 300" x 3.5" of 2x4 to 2x6 frame and the dow 795 seal for that acrylic to go anywhere. I'm confident it's not going anywhere.
Also, doubling up the 2x4. If you mean adding another on the top of the one that exists, will do nothing to help the strength of it since the bond is between the first 2x4 and the 2x6 next to it.