Alternatives to plexiglass?
- Thread starter vmiller
- Start date
Travis L. Stevens
New member
Why are you using PlexiGlass? You might want to check into Acrylic.
scotia-reefer
Premium Member
Vin - If you don't need it to be pretty go to Home Depot and get some rigid styrofoam. That will keep the water at temp and act as a good cover. Plus it will be cheaper and stronger. I covered a 20 long with 1/4" plexi and within a few weeks it was sagging like crazy.
scotia-reefer
Premium Member
I think they have an insulation department near the windows and doors. They might not have them as wide as you need but you can just get a couple and zip tie them together.
WinkeyWoneye
Premium Member
Sorry dont mean to pick on you here Dave.....BUT Plexiglass, Lucite, Lexan or any other brand name acrylic...is exactly that, Acrylic sheets....they are all the same exact materials. The only diffrences between them all is price, name brand, and the way they are manufactured. There is 2 ways to manufacture acrylic, what they call "cast" and "extruded". In aquarium applications Cast acrylic is most commonly used as it is stronger than Extruded acrylic and is more resistant to "crazing" (stress cracking) than extruded. I just spent 45 minutes looking for a thread on this, that I had seen not too long ago. No luck finding it again though. It explained the diffrences in the manufacturing process between cast and extruded acrylic.
Lucite may however be one of the more popular brand names of acrylic in the aquaria hobby as they probably only produce Cast acrylic. So when you see acrylic that seems expensive you are most likely getting cast acrylic as it is more expensive to manufacture. Just remember you get what ya pay for
or most of the time anyways. If unsure of the type of acrylic, for the price, than stay away from it. If someone at Lowes or the Cheapo cannot help you in finding out what type of acrylic it actually is than find a knowledgable supplier who can, possibly a glass company. As for stopping the sag in your current acrylic top.. Get a small strip of thicker acrylic and glue it to the middle of the flimsy one, length wise to act as a support. Or use the PVC as you mentioned to do the same thing. The only problems I see with using the PVC is it will block some lighting , possibly create shading, and astetically will possibly look crappy. Either way Good luck with the project.
EDIT: I missed you saying it doesnt have to be clear or pretty....than in that case your PVC idea seems like it should work just fine. I would use nothing thinner than Schedule 40 PVC though as PVC can also be flimsy when spanned in long lengths.
Polymethyl methacrylate (PMMA) or poly(methyl 2-methylpropenoate) is the synthetic polymer of methyl methacrylate. This thermoplastic and transparent plastic is sold by the tradenames Plexiglas, Perspex, Plazcryl,Acrylite, Acrylplast, Altuglas, and Lucite and is commonly called acrylic glass or simply acrylic. The material was developed in 1928 in various laboratories and was brought to market in 1933 by Rohm and Haas Company.
Properties
The material is often used as an alternative to glass. Differences in the properties of the two materials include:
PMMA is lighter: its density (1190 kg/m3) is about half that of glass.
PMMA does not shatter
PMMA is softer and more easily scratched than glass. This can be overcome with scratch-resistant coatings.
PMMA can be easily formed, by heating it to 100 degrees Celsius.
PMMA transmits more light (92% of visible light) than glass.
Unlike glass, PMMA does not filter UV (ultraviolet) light. PMMA transmits UV light, at best intensity, down to 300 nm. Some manufacturers coat their PMMA with UV films to add this property. On the other hand, PMMA molecules have great UV stability compared to polycarbonate.
PMMA allows infrared light of up to 2800 nm wavelength to pass. IR of longer wavelengths, up to 25,000 nm, are essentially blocked. Special formulations of colored PMMA exist to allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example).
PMMA can be joined using cyanoacrylate cement (so-called "Superglue"), or by using liquid di- or trichloromethane to dissolve the plastic at the joint which then fuses and sets, forming an almost invisible weld. PMMA can also be easily polished to restore cut edges to full transparency.
To produce 1 kg of PMMA, about 2 kg of petroleum is needed. In the presence of air, PMMA ignites at 460° C and burns completely to form only carbon dioxide and water.
If hydrogen atoms are substituted for the methyl groups (CH3) attached to the C atoms, poly(methyl acrylate) is produced. This soft white rubbery material is softer than PMMA because its long polymer chains are thinner and smoother and can more easily slide past each other.
PMMA Acrylic glass is commonly used for building residential and commercial grade aquariums.
PMMA is used for instance in the lenses of automobile running-lights. The spectator protection in ice hockey stadiums is made of PMMA, as are the largest windows and aquariums in the world. The material is used to produce laserdiscs, and sometimes also for DVDs, but the more expensive polycarbonate (also used for CDs) has better properties when exposed to moisture.
Chemical name poly(methyl 2-methylpropenoate)
Chemical formula (C5O2H8)n
Synonyms polymethylmethacrylate
PMMA
poly(methyl methacrylate)
methyl methacrylate resin
Molecular mass varies
CAS number 9011-14-7
Density 1.19 g/cm³
Melting point 130-140°C (265-285°F)
Boiling point 200.0 °C
Refractive index 1.492 (ë=589.3 nm)
V-number 55.3
SMILES C[C](C)C(=O)OC
Overview
Lucite® methyl methacrylate polymer was among the first plastics derived from petrochemicals. DuPont chemists discovered Lucite® in 1931 while exploring the high-pressure technology developed for ammonia production. The polymer’s crystal-clear appearance and its strength were far superior to nitrocellulose-based plastics.
sigh.... we all are right, and yes, it is a trade name, but LUCITE is used far more often as is is made slightly different that the common "plexi-glass". Plexi glass had more "give" to it and will bow easier where as LUCITE is a bit more fragile in thin sheets.
HTH
Properties
The material is often used as an alternative to glass. Differences in the properties of the two materials include:
PMMA is lighter: its density (1190 kg/m3) is about half that of glass.
PMMA does not shatter
PMMA is softer and more easily scratched than glass. This can be overcome with scratch-resistant coatings.
PMMA can be easily formed, by heating it to 100 degrees Celsius.
PMMA transmits more light (92% of visible light) than glass.
Unlike glass, PMMA does not filter UV (ultraviolet) light. PMMA transmits UV light, at best intensity, down to 300 nm. Some manufacturers coat their PMMA with UV films to add this property. On the other hand, PMMA molecules have great UV stability compared to polycarbonate.
PMMA allows infrared light of up to 2800 nm wavelength to pass. IR of longer wavelengths, up to 25,000 nm, are essentially blocked. Special formulations of colored PMMA exist to allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example).
PMMA can be joined using cyanoacrylate cement (so-called "Superglue"), or by using liquid di- or trichloromethane to dissolve the plastic at the joint which then fuses and sets, forming an almost invisible weld. PMMA can also be easily polished to restore cut edges to full transparency.
To produce 1 kg of PMMA, about 2 kg of petroleum is needed. In the presence of air, PMMA ignites at 460° C and burns completely to form only carbon dioxide and water.
If hydrogen atoms are substituted for the methyl groups (CH3) attached to the C atoms, poly(methyl acrylate) is produced. This soft white rubbery material is softer than PMMA because its long polymer chains are thinner and smoother and can more easily slide past each other.
PMMA Acrylic glass is commonly used for building residential and commercial grade aquariums.
PMMA is used for instance in the lenses of automobile running-lights. The spectator protection in ice hockey stadiums is made of PMMA, as are the largest windows and aquariums in the world. The material is used to produce laserdiscs, and sometimes also for DVDs, but the more expensive polycarbonate (also used for CDs) has better properties when exposed to moisture.
Chemical name poly(methyl 2-methylpropenoate)
Chemical formula (C5O2H8)n
Synonyms polymethylmethacrylate
PMMA
poly(methyl methacrylate)
methyl methacrylate resin
Molecular mass varies
CAS number 9011-14-7
Density 1.19 g/cm³
Melting point 130-140°C (265-285°F)
Boiling point 200.0 °C
Refractive index 1.492 (ë=589.3 nm)
V-number 55.3
SMILES C[C](C)C(=O)OC
Overview
Lucite® methyl methacrylate polymer was among the first plastics derived from petrochemicals. DuPont chemists discovered Lucite® in 1931 while exploring the high-pressure technology developed for ammonia production. The polymer’s crystal-clear appearance and its strength were far superior to nitrocellulose-based plastics.
sigh.... we all are right, and yes, it is a trade name, but LUCITE is used far more often as is is made slightly different that the common "plexi-glass". Plexi glass had more "give" to it and will bow easier where as LUCITE is a bit more fragile in thin sheets.
HTH
scotia-reefer
Premium Member
I hope this comes up on Jeopardy tonight! 
I feel so learned. It's like being in one of them big schools.
I feel so learned. It's like being in one of them big schools.
WinkeyWoneye
Premium Member
I dunno where in the heck you pulled that out of! Glad you found a breakdown of it , as my 45 minute search for that thread I saw made me late for work this morning LMAO. :lol:
Glad you found a breakdown of it , as my 45 minute search for that thread I saw made me late for work this morning LMAO. :lol:Dan.. remember.... I used to do this crap for a living
I think I've forgotten more information than links google could ever compile :lol:
The archives of my PC are mind boggling with innane drivel and random documents . If I could get my 170 MB hard drive to ever work again, I'd have 1/2 my book on it.... saddly it was corrupted when my PC died a few years ago.
I think I've forgotten more information than links google could ever compile :lol:
The archives of my PC are mind boggling with innane drivel and random documents . If I could get my 170 MB hard drive to ever work again, I'd have 1/2 my book on it.... saddly it was corrupted when my PC died a few years ago.
