Dec 15, 2019 - 12:19 PM
The Short Answer:
We prefer to use acrylic sheet to manufacturer all of our display and test tanks. The critical issue is to remain below acrylic materials' operating max temperature at all times. Most, but not all!, acrylics have a max temperature of 70C, so make sure to check the datasheet for your material before using it!
Acrylic is easy to work with, but you must only use chemical solvent welding techniques when building your tank, do not use any type of adhesive as we have seen that some adhesives are prone to failure due to pressure and temperature.
The Long Answer:
Poly(methyl) methacrylate (acrylic) and polycarbonate are both listed as "recommended" on our Materials Compatibility Guides (MGC), however please note that some brands of these materials may be subject to yellowing due to heat and age. Also, they have maximum operating temperature limits that must be observed at all times for safety.
In all cases you want to chemically weld the your tank parts together using typical solvents including Acetone and MEK (Methyl Ethyl Ketone). We use MEK as we find its faster and provides a stronger joint, however, your parts must butt against each other perfectly to get a joint without bubbles in it. Also please make sure you only use MEK in areas with excellent ventilation for safety as it has very strong fumes!
There are plenty of excellent YouTube videos showing you how to chemically weld acrylic using solvents, so we recommend you watch a few of these, and then practice a bit before you take on your own tank construction as its a little tricky until you get the hang of it. Also, we find using piano wire and guitar strings as spacers attached to story sticks so they can be simultaneously removed makes things much easier. Having two people also gets you better joints as one can hold the parts in place while the other applies the solvent and removes the spacers quickly and smoothly.
Products we use include:
Acrylic sheet marketed under the names: Plexiglas®, Acrylite®, Lucite®, Polycast®, Optix® and Chemcast®
Usable temperature range: -34°C to 70°C / -30°F to 158°F
Polycarbonate sheet marketed under the names: Lexan®, Makrolon®, Monogal®, Palsun®, Zelux®
Usable temperature range: -40C to 140C / -40F to 284F
We've done a lot testing with both acrylic and polycarbonate as we build tanks and containers with them for testing, demonstration units, and displays units for our customers. While both of these materials can be used to make demonstration tanks and displays, we have come to prefer the use of acrylic sheet as it has better scratch resistance, cheaper, and generally easier to work with. Polycarbonate sheet is definitely stronger and has a higher operating temperature, but we find it more difficult to get a clean chemical weld on these materials. However, plenty of professionals have no issue getting a good weld, its just practice!
If you are going to use these materials for large tanks, you can use the same recommendations in terms of thickness and strength that the manufacturer provides for use with water at the operating temperature you specify. Our Dielectric Coolants are 20% lighter than water, so you'll have an added safety margin in your design.