Without my final approval, my 11 year old daughter chose this - “When Air Masses Collide” as her 6th grade science experiment. Of course, I’ll be doing the bulk of the prep work. The commitment to this experiment is established - no turning back.
After one failed attempt with an odd-shaped tank, we now have a borrowed 10 gallon rectangular fish tank to use, although it has a plastic lip surrounding the top edge, effectively narrowing the opening slightly all around. This makes sliding a barrier straight up/down into a full tank impossible. We’ll have to fill the tank halfway, and rotate the barrier above the water to position it.
They suggest a piece of cardboard to separate the cold and hot water; I don’t see that as feasible. I’ve tried using a snug piece of foam board (styrofoam enclosed in heavy paper) but it leaked immediately. I’ve thought about putting a bead of silicone caulk around it, but that doesn’t strike me as much of an improvement. The material never cuts smoothly to begin with.
So, does anyone have a suggestion for an easily-cut and workable material to use as a (nearly) leakproof hot/cold barrier that will easily slide in and out of the tank without significantly disturbing the water?
A couple of good demos on YouTube, maybe will give you some ideas?
Here.
and here.
and here.
and here.
Maybe contact the videos’ owners, and ask for details?
In the absence of any other ideas, I’d suggest you laminate multiple layers of cardboard using 3M Super77 spray, and then cut with a straightedge and utility knife. This would give you a very rigid panel, but creates a material that cuts relatively easily.
You mentioned a lip at the rim of the tank. So put weatherstripping foam on the acquarium glass, using thick enough foam so that your removable panel is narrower than the distance between the lips at the top of the tank. You might have to put electrical tape around the edges of your carboard panel to create smooth surfaces that slide over the foam without tearing it.
Leakage around the panel can also be minimized by filling both sides of the tank at the same time.
The plastic lip usually helps hold the tank together. You can wrap fiber-reinforced tape around the top of the tank below the lip for strength and then cut slots through lip so you can insert the barrier. But it will be tough getting it to seal well unless you put some gasket material around the edges of the barrier that contact the glass. You can also get plastic edge molding that extends past the lip and silicone it to the sides and bottom of the tank, similar to this.
Thanks for your assistance, Tri & Elf…I didn’t want to cut the lip, as I had done this with the previously-borrowed tank (from same friend) and didn’t want to ruin two tanks.
I was able to use some weatherstripping foam I had lying around. Wrapping packing tape around two pieces of cardboard joined with Super77 spray (as Machine Elf suggested), we were able to conduct about 6 trials with little to no leakage. While the experiments didn’t look as dramatic as those in the videos, there was good separation between the layers and some decent “wavefront” motion.
Thanks again guys!