# Acrylic vs Glass...Which is stronger?



## Guest (Mar 2, 2005)

First of all, is Acrylic just plexiglass? Also, if I were to build a tank, which of the two would be stronger?

--Dan


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## elTwitcho (Jun 22, 2004)

Depends on what you define as "stronger". Glass will not bend at all really while plexiglass is bendable to a fairly large extent and always requires a top brace to hold the tank together. Glass can shatter while plexiglass is almost unbreakable in terms of sharp blows. Glass will not scratch as easily as plexiglass while plexiglass has a softer finish.


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## Guest (Mar 2, 2005)

Bendable? Yikes, I dont know if thats a good thing or a bad thing....

--Dan


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## elTwitcho (Jun 22, 2004)

With a brace the bowing is kept to a minimum and it doesn't really affect the strength of the tank. So long as the seams hold, you won't have any problems.


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## RhomZilla (Feb 12, 2003)

elTwitcho said:


> Depends on what you define as "stronger". Glass will not bend at all really while plexiglass is bendable to a fairly large extent and always requires a top brace to hold the tank together. Glass can shatter while plexiglass is almost unbreakable in terms of sharp blows. Glass will not scratch as easily as plexiglass while plexiglass has a softer finish.
> [snapback]915892[/snapback]​


Saved me time on posting the sane info.


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## Guest (Mar 2, 2005)

elTwitcho said:


> With a brace the bowing is kept to a minimum and it doesn't really affect the strength of the tank. So long as the seams hold, you won't have any problems.
> [snapback]915934[/snapback]​


Im a little discouraged now, the last thing I need is the window on my tank poppin out, or leaking out the sides...

Maybe glass would be easier?

It's just I have easy access to quality plexi for cheap...

--Dan


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## hyphen (Apr 4, 2004)

glass is definitely cheaper. but it depends on what route you want to go. for larger tanks many people prefer acrylic/plexiglass. when they say bend/bow, they don't mean that you'll be seeing a bulge on the sides of the tank. it's just that the pressure of the water pushes outward and you'll notice that the panes are not perfectly flat, that's what the braces are for.

if you can get plexiglass for cheap, definitely do it. it won't crack or shatter. the downside is that it scratches much easier.


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## taylorhedrich (Mar 2, 2005)

From what I've heard about plexiglass is that it is the way to go when purchasing an aquarium. I've heard that it is more durable as far as not breaking, and I've also heard that it is much better insulated than glass, so it prevents heat fluctuations. Hope this helps you.


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## DepH (Jan 11, 2005)

I thought acryl was some type of glue. Like instead of silicone. We use to tighten between the doors and the floor etc. 
Have I misunderstood totally?


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## JAC (Jan 19, 2004)

Another advantage of plexiglass is that it is VERY light compared to glass, my 105gal tank(glass) is very heavy but an acrylic tank of the same size shouldn't weight more than 30 kilos.

To me the gratest disadvantage of acrylic is that it scratches very easily .


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## Scolopendra (Feb 24, 2005)

Sure ur not talkin about silicone DepH.....?

I like Plexi for is nice clear seams and 1 guy can move a 90-100 gallon tank without breaking his back...







But im clumbsy and scratch all that is plastic with rock work usually.....some say plexi will look like crud after a few years from scratches. My dads had the same tank (40 plexi) for about 18 years! It survived me and 2 siblings. If you can afford it i would go with plexi for the shear clean look combined with thfact that if it need be moved....it wont take a crew.


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## Natt King Shoal (Aug 7, 2004)

Acrylic (AKA plexiglass) is 17 times stronger than Glass. It is about 1/2 the weight of glass but scratches easily and is usually more expensive. It is a better insulator than glass and can be molded to create unusual shapes.


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## Guest (Mar 2, 2005)

I wanted to try building a betta barracks for my g/f who loves bettas, using a huge extra peice and some plywood, but it looks like Im not ready for that yet







If I canty figure out the plexi, I'll never find the right type of epoxy sealant, let alone put the thing together properly









--Dan


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## illnino (Mar 6, 2004)

plexy is the way to go for diy tanks. btw, you use stuff called acrilic cement to bond it, it basically melts tghe two pieces togeather.


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## Mykoe817 (Feb 13, 2005)

DannyBoy17 said:


> Bendable? Yikes, I dont know if thats a good thing or a bad thing....
> 
> --Dan
> [snapback]915932[/snapback]​


It depends on which company you go with. Sea clear tends to use the minimum acrylic and will bow ,
Tenecor makes there tanks with thicker material.


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## viZual (Jan 16, 2005)

DepH said:


> I thought acryl was some type of glue. Like instead of silicone. We use to tighten between the doors and the floor etc.
> Have I misunderstood totally?
> 
> 
> ...


acrylic is plexiglass or high-class plastic. it is what most people prefer there tanks to be. all silicone is pretty much the same, besides the grades and there uses. and yes. you have misunderstood totally.

as for dan..
i would definitely go with plexiglass. although it seems that glass is more durable. that idea is totally wrong. i had a 55 gallon glass that was custom made and it burst. plexiglass not only holds water better and is stronger, it is easier to produce a tighter bond because of it's softer and tougher texture. depending on your price limit, try going to your lfs and looking at the tanks with the rounded front corners. those have a lifetime warranty against leakage. basically making them leak proof. if you can or have a way of bending the acrylic at a right angle. use that method instead of having 5 individual pieces. you'll have one for the sides and front and one for back and bottom. good luck with your project.


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## Speedy (Sep 25, 2004)

Hi All,
Just a little education regarding the different types of plastics vs. glass...
All of the following "types" fall into the family called "Acrylics"

The term "Plexiglass" is most commonly referred to techically as "Polymask or Papermask"... Neither product is suitable for tanks as it can and will likely crack, sag, discolour, and scratch very easily, no matter how thick it is...This is the cheapest type of acrylic product available.
Don't ever buy this thinking it will work for your DIY tank...You'll regret it.

The term "Lexan" or sometimes "Bullet-Proof Glass" is actually technically referred to as "Polycarbonate" and will not crack, discolour, or sag over time.
In fact, it cannot be cut using the same methods as Plexiglass, as it must be cut with a saw... This product is substantially more expensive but still scratches easily.

The term "Margaurd" is really the same as above but has a micro-thin coating of silicone on it and is hardened more to prevent scratches from occurring so easily.
This is the material used in many professional racecar windshields.
Don't be fooled though....It still scratches easier then glass.

The bottom line is that, with the exception of "Plexiglass" in some cases, all acrylics are more costly then basic "annealed or float" glass product.

There are many pros and cons for both glass and acrylic use in home aquariums, however whenever I measure them, I come up with even results.
What I mean is that if you demand a "crystal clear" view into your tank and don't mind paying a high price for it...Then polycarbonates are the way to go.
If you want durability over many years and can afford to have the added weight of an all-glass aquarium in your viewing room...Then go with glass.
I could likely go on and on but my point was to tell everyone about the difference between Plexiglass and what they use to professionally manufacture aquariums.

By the way, in case you're wondering, I've been working in the glass business for more then 20 years now... Yes we often use plastics too for some applications.

Hope this helps anyone considering using arylic for their next DIY project.

Speedy


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## JustinRice (Feb 24, 2005)

My 33 Gallon has a Slight Bow in it and its made of glass. IS this normal? it don't show any sign in cracking or strain and does not leak.....


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## FrontMan (Feb 7, 2005)

With all this stuff there are more elements to them than just saying "stronger".

Both glass and Plexi come in different thicknesses... and the thicker the material, usually the stronger it is.

Not to mention that Glass has different processes like Tempering that increase its hardness...

so, I think there are some other questions you should ask... and some information that you need to think about...

IMO


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## Dr. Giggles (Oct 18, 2003)

Acrylic is lighter and stronger and the scratches can be buffed out to new condition.


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## Puff (Feb 14, 2005)

to solve the whole scratchign issue with plexi. wouldnt you be able to use an environmentally friendly diamond coat or something on the indside to stop scratching???

has anyone tried that? i know you can get enviro friendly hard coats...somewhere out there


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## Speedy (Sep 25, 2004)

JustinRice said:


> My 33 Gallon has a Slight Bow in it and its made of glass. IS this normal? it don't show any sign in cracking or strain and does not leak.....
> [snapback]922852[/snapback]​


Justin,
My 1/2" all glass 200gl bows in the centre too and it's not uncommon to do so...
However with a tank this size you also need braces to keep it from bowing out to the point it actually breaks the glass or the actual bond to the rest of the tank.
Whether or not it's Acrylic or Glass, braces should always be used on large tanks.

If anyone is still wondering about the difference between Plexiglass and Lexan, just drop by a local glass or plastics shop and ask them to demonstrate it for you.
You cannot break Lexan by "scribing and cracking" it...At least not properly.
Plexiglass will "crack or split" with the least amount of stress and also discolour.

Many people out there think that the term "Plexiglass" encompasses every kind of acrylic out there that they can build an aquarium out of.
Besides Glass, "Polycarbonates" are the only plastics suitable for this!









Speedy


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