Plywood tank build: Multiple viewing panel question.

[Phil125]

I was given 3 - 47" x 34" x 1/2" Acrylic sheets for free.

I was thinking of building a roughly 12' x 36" x 36" plywood with 2x4 & 2x6 frame. It would have three viewing panels probably 42" x 30". I have made plywood tanks before, but nothing of this size. The free acrylic gave me some motivation. My question is would 1/2" be fine for this build? and could go wider? say to 40" or 42"

The acrylic was used as the bullet proof panels that protected Hillary Clinton when she came to our area during the election. When they were done they told the stage crew to toss them. There were 8 or 9 of the panels. Couple grand of acrylic bought by taxpayers for single use and thrown out. lovely....

 

[Deadliestviper7]

Give em a try, if their the projectile rated ones than they are probably denser, put our tax dollars to work for something better than protecting a monster

 

[Phil125]

Give em a try, if their the projectile rated ones than they are probably denser, put our tax dollars to work for something better than protecting a monster

hmm now you got me thinking. These could be Polycarbonate which is usually what they use for bulletproofing. Which would make them considerably stronger than acrylic. Don't want to push my luck though. I thought acrylic because the guy I got them from said acrylic, but they probably are polycarbonate.

Wonder if there is a way to tell the difference? If i knew for sure I think I would probably be safe to push it a little wider.

 

[wokka]

Unless someone really messed up, these are polycarbinate

Had to determine between polycarb and acrylic when panels got mixed up on a packdown myself.
FYI
Polycarb yellows in sunlight
Check clarity, Acrylic is clearer
Poly carb scratches much easier than acrylic
If you still arent sure, grab a Mapp torch and apply to the edge for 3 or 4 seconds. Acrylic will polish up under the flame, Poly carb will blacken

 

[esoxlucius]

Yeah I agree, these sheets if used for the purpose you say, are definitely polycarbonate. My job is in plastics, or the recycling of to be more exact. There are subtle differences to the eye if you know what you are looking for but the best way, as mentioned is just to burn the corner of one of the sheets, just until it ignites. The resultant flame, and smell for that matter, are a world apart on each of these polymers.

When you light acrylic the flame will be calm, no flickering or spitting or popping (unlike some plastics). When it is lit, blow the flame out and you immediately see slight bubbling on the surface of the distinguished area. Also the resultant fumes are quite sweet smelling.

Now polycarbonate is the complete opposite. It's not easily lit, as you pull the lighter away the flame mostly self extinguishes itself. That's one tell tale sign. If you do manage to light it the flame flickers (unlike the calm flame of acrylic). That's your second tell tale sign. The third is that the resultant smell is acrid, not nice at all. And if that hasn't sealed the deal for you burnt polycarbonate will have a black crusty carbonised area where it was burnt, acrylic won't.

Hope this helps.

 

[Phil125]

Thanks guys ill try that on a piece scrap i have from a fourth sheet i already cut