# Lexan (polycarbonate)



## boogsawaste (Jun 28, 2008)

Ok, I've been searching on here trying to find an answer. I've seen people saying that lexan will warp the same as other plexi glass and others saying it can't because it cannot absorb water. Who's right? I have no idea! I want to replace the front half of the top of my 44 gallon pentagon tank with polycarbonate from home depot. I'm not sure of the thickness but I imagine it's pretty thin, 1/8th inch maybe? I absolutely do not have the patients to drill through the glass top. Nor do I have a diamond bit, drill press, or a spare top to drill through because my inhabitants are already in the tank. 

I wish I thought of this before, but I have since ordered a misting kit that needs a couple holes drilled and also want to put in a spot for my fan.

So, bottom line of people with experience or knowledge of plastic. Will polycarbonate (lexan) warp over the top of a dart tank? And What is the minimal thickness I could use? Thanks for any help!


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## Conman3880 (Jul 8, 2007)

I use 1/8" lexan for the fronts of my 10g verts. My oldest has been up & running for about 6 months with zero warping... and not showing and signs of doing so any time soon.


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## scott r (Mar 2, 2008)

Yes, Lexan will absorb water. However, it will absorb something like 1% totally submerged for extended periods, and this one percent is not enough absorbsion to cause warping.
I use polycarbonate for all of my enclosures, and alot of other things. You can cut it with regular woodworking tools.
Lexan is GEs namebrand. Use it. Rhinotough is another brand, and the paper is hard to remove without scratching.


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## jubjub47 (Sep 9, 2008)

My recommendation is to pick the thickness you want then go one size thicker. We do some lexan tops on some of our custom aquariums at work and the lights at times will cause a bit of warping. Usually the thicker you go the better off you'll be though. And for whatever reason, they don't always warp so you might get lucky. That's why I recommend going a step thicker.


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## boogsawaste (Jun 28, 2008)

Ok, sounds like it will work out for me then. I'll have to look around for thicker pieces. Is it possible to seal 2 together if I can't find the right thickness?

EDIT: Will 1/4" be ok? The area is a trapezoid. Measurements are 21" long at the top, 9.5" down the straight side, and the other 2 sides are 12"


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## jubjub47 (Sep 9, 2008)

That should be safe.


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## scott r (Mar 2, 2008)

1/4 inch will work just fine.


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## boogsawaste (Jun 28, 2008)

Good deal guys, thanks!

~Jim


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## parkanz2 (Sep 25, 2008)

What products do you use to weld pieces of polycarb together? is there a different weldon product good for polycarb?
max


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## scott r (Mar 2, 2008)

I use silicone


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## nish07 (Mar 16, 2008)

Weldon 16 might be fine and I'm using Lexel for acrylic to metal and metal to glass. Lexel isn't FDA approved for submerged tank use though (I get the impression most of the possible problem is due to the product before the curing process has completed).

-Nish


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## JJuchems (Feb 16, 2004)

I have used Lexan with no issues.


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## ofblong (Sep 11, 2008)

scott r said:


> I use silicone


silicone doesnt properly seal to any plastic. Silicone will eventually break away.


use weld on. I use weld on 3 at work. I have made box's out of it that get banged around and knocked into metal machinery because people dont care. I have yet to have one brake in the 7 years I have been welding lexan and acrylic together with weld on 3. Its not really "welding" but the weld on causes a chemical reaction in the lexan to melt the pieces together.


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## scott r (Mar 2, 2008)

I have an enclosure I built out of Lexan in 1997, and used silicone for all of my joints and it hasn't failed me yet. Eleven years and counting.


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## boogsawaste (Jun 28, 2008)

Well I just ordered some 1/4" polycarbonate and will cut it to size when I receive it. Thanks for they help!


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## boogsawaste (Jun 28, 2008)

Got a little warping...Well it might be a design flaw. Those dimensions I gave early are accurate, but the 21" section is NOT supported. It has warped about 1/8" down in the middle. I don't know if it will go any farther. Any ideas? 

Is there anything I can do to fix this? I have the original glass piece that goes on there but cannot locate the hinge that took up the gap where the 2 pieces went together, which is about 1/4". So any fixes with the lexan still on the tank is best. Does anyone make a hinge that adapts regular aquarium top glass to 1/4"? Any help is appreciated!


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## nish07 (Mar 16, 2008)

You can always try and frame the lexan using extruded aluminum U channel. That'll support it. You can then hinge it with any aquarium type hinge. Glasscages.com has both the black and the clear but be aware that the clear makes a larger gap between the pieces yet at the same time will hold thicker glass (I believe it's closer to 1/4 inch gap but you can make up a little bit with the aluminum frame (not much though).

-Nish


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## boogsawaste (Jun 28, 2008)

Cool, what is that u channel stuff usually used for? Just so I know where to find it in the hardware store. Or if you know what section it would be in.

The 1/4" gap is only there when I have the 2 pieces of glass on without the hinge installed. But I took the front glass off and have the lexan on there and there is basically no gap. Well, maybe 1/16".


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## nish07 (Mar 16, 2008)

Brunner - aluminum channel, extruded aluminum angle, anodized aluminum shapes, aluminum pipe, bar, tube, square tubing connector,aluminum channel, extruded aluminum angle, anodized aluminum shapes, aluminum pipe, bar, tube, square tubing connector, a

It's used to frame glass (acrylic too I'd imagine). If you're going to have no space then you might not need a hinge. The U channel will add a very small ammt of length to the glass (width too unless you decide to not use it on the sides).

I'm not sure why you chose lexan to begin with over glass. I'd think it'd be more expensive. Either way, that'll work but remember the width added by the thickness of the U channel and also remember you're going to need some decent ammt of space between the two pieces for the hinge (though like I said you might not need one if they fit close enough that flies can't get out).

-Nish





boogsawaste said:


> Cool, what is that u channel stuff usually used for? Just so I know where to find it in the hardware store. Or if you know what section it would be in.
> 
> The 1/4" gap is only there when I have the 2 pieces of glass on without the hinge installed. But I took the front glass off and have the lexan on there and there is basically no gap. Well, maybe 1/16".


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## boogsawaste (Jun 28, 2008)

I used the lexan simply because I got a piece cut to size shipped to me off of ebay cheaper than a diamond bit to drill out my holes for my misting nozzles. I also am not interested in drilling glass. I might take my original piece of glass to a shop around here and see if they could drill a couple holes for me. That was not an option until I put the lexan on top because the frogs are in that tank. I'll have to buy another hinge if I go back with the all glass top. Also, I don't need a hinge with the mixed top. Thanks for the info.


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