cheap plexiglass store.

E

Everfalling

Gawd
Joined
Jul 12, 2005
Messages
676
anyone know of a good online store that sells sheets of plexi glass for relatively cheap? i got a quote from my local plastics store and they said that six 18"x18" sheets of 3/16" plexi will run me about $67.50. i'm thinking that's kinda high, but i've never shopped for plexiglass before.
 
tap and us plastics are i think generally viewed as the place you wanna go... but if all you need is clear, any home improvement store should have it pretty inexpensively (lowes/homedepot) i know at lowes you can also have them cut the plexi to size for you, might save you some time/$.

-El
 
jeez, a place called modern plastics here sells it by the pound, dirt cheap too i think the sheet i used to temporarily replace the window upstairs that broke was $3 and change
 
i just checked their website, i wish it wasn't all the way out in san jose, cause the website has what i need, but they only sell one sheet size, and the thing is huge and is like 200 bucks. oh well. keep the websites commin. i'm gonna go back to my thing and see exactly how big my pieces are and see if i can't squeeze what i need down.
 
id be interested where we can get it in multiple colors, red blue green, etc.. i see it in mods all the time, no idea where it comes from though
 
I gotta be up front with you guys, if you're looking for specific colors, you're going to have to shell out some money to get the right stuff. 6x sheets of 18x18 for $67 is a deal. Now don't make the mistake and think because 3/16 is thinner than 1/4 that it's cheaper. Tap plastics will sometimes have higher prices on 3/16" and odd thicknesses because they don't order a lot of it. I don't know if others do that but I'd assume so.

So if you can, stick to 1/8" or 1/4".
 
they charge more for the 1/4". and all i want is clear plastic sheeting. if not 6 sheets of 18"x18", then two of 36"x36" maybe? donno if that's be cheaper cause they have to cut less...

well tomorrow i'm getting a protractor, so i can measure out exactly the pieces i need si can maybe shorten my order.
 
Well if you don't have the tools to cut it exact I wouldn't ask for larger.

Since it's just clear, go to home depot and see what they have. Clear is cheap in general. Compared to the colored transpared, it's a bargain.
 
Everfalling said:
i just checked their website, i wish it wasn't all the way out in san jose, cause the website has what i need, but they only sell one sheet size, and the thing is huge and is like 200 bucks. oh well. keep the websites commin. i'm gonna go back to my thing and see exactly how big my pieces are and see if i can't squeeze what i need down.
Click to expand...


See that y having the store nearby pays. they sell the "left over" in their storefort dirt cheap. Say you need a 18x18" peice and u find one in their "spare room" that's 19x22 that was left over from one of those huge sheets. it's like 1 dollar a pound.
 
ok, after talking with a guy at a fish store, he said glass would actually be cheaper, stronger,and easier to put together. he said if you screw up on bonding the plexiglass, you gotta cut away what you messed up on and try again. but with glass, the bonding agent is far easier to apply.

ok, i made the assumption that plexiwas going to be cheaper. guess i was wrong. so, does anyone know of a place that does custom glass cutting jobs? i'm thinking i can make cardboard templates, tell them to cut the pieces,and just bond them together myself.
 
glass wont be stronger, that is kinda the whole point about plexiglass, its stronger and more workable.

when you glue 2 pieces of plexi together with say wledon, they physically become 1 piece, so if you make a mistake, you can't just scrape the glue off...

Glass is just difficult to work with though, and i think thats the reason most people stay away from it. But if you are really keen on the idea, then, if you only want sheets cut, then Lowes will cut glass to any size rectangle... if you are looking for more intricate cuts, esp if you need a cut on the interior plane of the glass i would check with a local autoglass place and see what they would charge you.

plexi vs glass:

Strength (impact resistance): depending on what type you buy, plexi can be 10-100 times stronger and more resistant to crack/shatering then glass.
Ridgidty (warp resistance): plexi in thinner sheets is plyable and offers little to no warp resistance. Glass on the other hand is very ridgid even at thinner samples.
Durability (scratch resistance): glass is very hard to scratch, plexi is notorious for developing scratches, but in the same token, scratches in plexi can be delt with using a buffing kit.
Weight: depending on that type of plexi you are using, glass will be 2-10 times heavier then the same size/thickness of plexi.
optical clarity: glass is very good, most good acrylic is a little better, most cheap acrylic is a little worse.
Chemical resistance: plexi is resistant to many chemicals, acids, bases, salts, etc but it WILL react with some, the one most worth mentioning is alcohol, including the isoproyl and drinking varieties. These will cause small cracks to form (crazing). Acrylic can be exposed to alcohol in dilute solutions for cleaning, but high concentrations and prolonged exposure are very bad. If you dont mind paying a bit extra, some acrylics can be made to be more resistnat to a given chemical type. As for glass... not much phases it, esp in limited contact.
Shaping: Plexi is much more capable of being formed to shape, heating plexi to arond 400 degrees with a heat gun tends to be sufficient. heating and bending plexi slightly reduces clarity. In the case of glass, it can be heated to be bent or shaped, but it is much more difficult most heat guns arnt sufficiant, repeated heating/cooling can result in the glass cracking or shattering (dont ask how i know this) Also heating and bending glass greatly reduces its clarity.
Bonding: bonding 2 pieces of acrylic propperly results in a joint almost as strong as the sheet itself, the pieces 'melt' into 1 piece. while this is very strong, mistakes are costly, also the bonding agent (the weldon) will mark up any other acrylic it touches from run off/spilling. I've never bonded glass, so i dunno, but from all indications ive read/seen silicone 'goop' is used to join 2 pieces. not sure *looks blank*
Workability: all acylic will crack if not worked correctly, but if the correct precautions are taken, the chance of this happening is reduced to almost nothing. I have never cracked a piece of acylic by drilling/dremeling/sawing it. The only time i have ever tried to drill glass, it went... poorly and ill never do it again. But ill grant that i didnt know what i was doing at the time your results might be better~
 
ok, this is what i'm wondering. bonding plexi, you said it basically melts the plexi together. does the plexi bonding agent melt to the plexi as well, filling the spaces between? or does it ust chemically heat the plexi, let them join though pressure, then disappear, leaving only plexi? cause i'm thinking, if the bonding agent itself was also part of that seam, couldn't it go back and fill the gaps? let it melt again?

and if not, how do i make sure that i've filled all the gaps? i can't really apply the bonding, then put 15 gallons worth of water pressure behind said seal...

it seems like the 'goop' for glass seems a little more mistake proof, in that it's like caulking, and that any mistakes could prolly be scraped away and reapplied...i'm guessing...

so basically my problems are cost to cut either material, and risks in bonding said material together. if those risks fall more heavily on one side, i'm goin with the other i guess.

the strength/rigidity thing is another problem. plexi will bend, but not break as easily as glass. buy, glass doesn't bent at all, but if it does, it shatters. will, lets say a 14"x14" sheet of 3/16" plexy withstand the pressure of 15 gallons of water behind it, and will it bend if only 3 out of 4 sides of the 'cube' are bonded to it? and how thick will i need the glass to be to keepstrong for the same situation?

shaping is another problem. if it'x plexi, i'd prolly try to shape it myself, but that's where the bonding issues come in. f i dont make a stright enough edge i could be screwed. glass, on the other hand, i'd ust get someone else to do it. i'm not touching glass, i like my fingers. i think if i knew how to properly use those glass cutters i'd be ok. but i dont so..oh well. heh
 
the strength/rigidity thing is another problem. plexi will bend, but not break as easily as glass. buy, glass doesn't bent at all, but if it does, it shatters. will, lets say a 14"x14" sheet of 3/16" plexy withstand the pressure of 15 gallons of water behind it,
Click to expand...

Are you looking to make a fishtank?

Plexi will not work as the base of a fishtank unless you use a very thick piece or have a fishtank stance with a fill, suporting base... the bases where the middle is open are a bad idea.

welding acylic isnt accomplished by heat (not exactly anyway) it happens chemically, and can happen with a variety of agents in different viscosities. Weld on 3 and weldon 4 are water thin and are best for aplications where there is solid contact, this will evaporate and leave next to no trace. Weldon 16 has the viscosity of maple syrup (maybe a little thinner) and will work to help fill *small* gaps... very small gaps... I use this stuff a lot. for large gaps you need a structural adhesive I have never had call to use it, but i think Weldon 40 is what is needed for this. it is a 2 part compound like epoxi resin that will bond to acrylic and form acrylic to fill in spaces.

I have gotten very good water tight seals from weldon 3 using this trick, pour some weldon into a container, dip the edge of one of the pieces you wish to bond into this for 1-2 mins... put this piece into place with the other piece and apply pressure to the edge. At this point i tend to put a small amount of weldon3 along the seam while continuing the pressure to ensure that none-dipped piece is able to react and bond. Dipping the first piece softens the edge to a point where the pressure will cause any small gaps to be forced out. this takes some practice.
 
Oldwolf said:
Have you tried Tapplastics.com???
Click to expand...

umm. i said i did, that's where i got my first quote of $67.50. well, not the online store, but he B&M store near me.

Elleric: why does the base need to be thicker? i'm assuming it's cause water pressure is more there, but i wanna be sure... and what's a stand with a fill? like, a wooden frame with a depression for the glass to sit in or something?
 
The base of the fish tank needs to suport MUCH more then the sidewalls, using a pice of 3/4 inch plexi (dont know if you even need to go that thick) will make it so it is ridgid. The side walls dont have the full weight of all the water pressing on them. if yuor tank is cubed 14 inches, the 196 square inches of the base is suporting the full weight of the water, while the sides are suporting the water combined, so there you have 784 square inches to absorb the pressure. This analysis lacks a few (a lot of) factors but give you the idea.

the 'fill stand' was a typo, my bad, ment full. If you have an 'open' fishtank stand, where only the edges of the tank are suported then the plexi base, if its thin will warp and start to pull at the seams, which will causemore stress, which will cause more of a warp which will further pull at the seams untill the inevitable happens.... you need a stand that is more like a table top, so the full base of the tank sits on solid material. Also, cutting a piece of plywood and putting it on your open stand will work too. You would be surprised i think by how many fish tank stands dont completely suport the bottom of the tank >< this is bad for acylic because of the warping, but doesnt matter much for glass except in larger tanks.

I am a fan of plexiglass because of how easy it is to work with and i dont like glass because of how hard i think it is to work with...(a few bad experiances) In this case to use the 'easier' material you need to just do a little extra prep work.
 
well the base will be sitting inside the monitors plastic casing, so it's got full base support there. only problem is how strong the plastic casing is in the first place. but yeah, i'll prolly spring for a thicker base if t comes to that. thanks.

i'm in the process of making my templates in cardboard,so when i'm done i'll post pictures along with the pieces put together to show what the shape of the tank is gonna be.
 
here's the gerneral template and how it's assembled. hope it's not too confusing. i left out the actual measurements for the sake of time and, well, you dont really need them right?

fishtanktemplateol1.gif


looking at this, is there any reason i should get either material over the other? or wouldn't it matter?

ps: kinda looks like the tree of life huh? like in evangelion? no? ok just me then...
 
So your hope is to occupy the entire interior of a CRT display with a fishtank? Making that happen should be interesting.

Anyway, i havecontinued suport of using acrylic, 1/4 inch would work fine all around. With this many joints the likelyhood of a mistake in bonding might push you towards glass though... But i would Try to make the base all one piece, maybe be using some wood inside the monitor's floor to even it out, id do that using either material. Edit: i miss read the diagram, i see there is a single piece for the base. the top being wider threw me off.

When you are making your measurments though, dont be like me and forget to account for the thickness of the material your first time... glass or plastic...

Are you planning to have this stuff laser cut? there are a lot of joints and measurments to mark and cut by hand...

last night after following the thread all day at work i made a run at making a water tight container using plexiglass scraps i had sitting around. It took about 2 hours. It is no where near this complex, it only holds about 1.5 liters, but might give an idea of working with plexi a little. For glass, you're on your own though!

As you work on this, keep a work log, im really interested to see how this comes out

-El
 
yeah those are some of my worries. considering how complicated these masurments are, and how many piece i have to put together,the risk for mistake is almost exponentally harder than ust gluing together a cube or something.

and yeah, i'm not sure how i'm gonna deal with the thickness issue considering the material. so far i've been measuring off the less than 1mm metal chassis within the monitor, and making a cardboard mockup with equally thin posterboard. things didn't fit the first time because of a minor miscalculation, but i'm hoping it works next time.

see, with glass, i'm thinking i could bond two sides together by the corners of their edges, so that the sides meet kinda like this: X instead of like this: |--. cause i'm thinking with plexi, the sides need to be pressing up against eachother, while with glass it's just a matter of filling gaps with that goop.

thing is, this thing is hard enough to measure and have everything fit together without considering how precisely the sides will be bonded together, and how thick said sides are gonna be. the price between 3/16ths inch thick and 1/4th inch thick jumps my $67.50 to a little over $100, so what thickness these sides will eventually be depends on whether or not i choose 1/4th for all the sides, or just the base, and if i have them just cut it all for me instead of doing it myself.

arg, so many factors, not enough money to make many mistakes. but still, considering the cost of most fish tanks i guess i'm getting off cheap. heh
 
Building on the inside of the case is going to be hard, and im not sure abotu the bonding strength of the glass 'goop' to suport a kitty-cornered bond, before you go forward with that id ask around on how strong its going to be. Would the pieces need to be set inside the monitor case for bonding? or can you buildthe tank externally and then place it into the outer casing? Id find a way to do the later at any cost.

here is what i threw together for testing water tight seals with acrylic...

some extra plexi i had sitting here...
a1.jpg

getting ready to bend it some
a2.jpg

seekrit bending tools~ ok, maybe not so seekrit
a4.jpg
a3.jpg

Use the covered board to make a nice clean bend along the 'mold'
a5.jpg

Problem with making a good bend is sometimes the edges buldge a little... sand paper to fix it...
a6.jpg

more scrap plexi, this was what was left from my cube....
a7.jpg

cut
a8.jpg

stuck the 2 together for rough finishing to make sure they were the same
a9.jpg

good edge
a10.jpg

glue and glue aplicator (tap version of weldon 3)
a11.jpg

bent plexi soaking for 1-2 mins
a12.jpg

high-tech mounting system
a13.jpg

20 mins later... soak the other side...
a14.jpg

more fancy pressure aplication
a15.jpg

and finally the good seal... 3 hours later... water was cold when i added it thats condensation on there
a16.jpg


no leaks this morning, good deal... hoppe i can say the same when i get home tonight.

like i said, much less complex then your idea, but hope to give an idea of how easy the wleding of 2 pieces of plexi is. I used blue painters tape to make things off and make sure everything lined up. bonds take 20 mins to set, 3 hours to completely bond. this took me about 2 hours to bend, cut, sand, bond... then played titanquest for 3 hours for the stuff to completely set.

]might get a fish to put in there tonight, other wise i dunno wtf to do with it. /shrug
 
thanks for the little tutorial, but the way i'm gonna end up doing it, you'd have to have four seperate pieces, instead of one bent, and that last two pieces, the black ones on the side, should be cut into triangles accordingly. NOW put them together

thing is, i dont have the luxury to bend the plexi, though it would make things much much simpler.

here's a more accurate diagram of my layout, complete with current measurments. i'm praying they work the second time around. i'm gonna go buy thciker cardboard for it i think:

fishtanktemplaterealig1.gif
fishtanktemplateol1.gif


now looking at that, and the previous diagram, the ajoining 'back','top','base' and the two 'side's COULD be all one piece, then all bent inward with 'back' being the center point. thing is, that's a combined height and width of about 33"x44" (hxw). that's a pretty big sheet of plexi, not to mention all cuts would have to be perfect on such a large panel,and all bends would have to be perfect as well. and still you'd have the issue of bonding two edges at a right angle when not only do the edges meet like this: X but it widens toward the 'back' where the bends round off. only way to solve that would be to get some kinda bonding agent that not only bonds, but fills gaps. the weldon 3 with it's water like consistancy prolly would't be able to do that.

what i wish, is that i had the ability to cut whatever material i use like plexi, to allow for slith changes incase it's too big, and the ability to use a goop bonder like for glass so i dont gotta worry as much with screwing up the seal. but alas, it seems i'm split between having one or the other :/


update: i've called 5 glass places in my area, and i sent them the above template. waiting back to hear the prices of the cuts. hope they're reasonable. heh...
 
Good luck. remember to take pics of progress, we "less then three" pics of work :)
 
hey, quick question, if i get 1/4" glass, and i fail to compansate my measurments accordingly, can i take the flat edge of the glass ] and dremel it so it becomes a somewhat 45 degree angle \ ? cause then if i can't fit the glass like this: -|- then i can bond them like this: |/_ if that makes any sence.
 
i really dont know on glass. maybe if you are super careful, but it's risky
 
crap. so far i think two people have called saying that the L shaped cut is impossible w/o laser cutting, and they dont laser cut :/
 
ok. i think i'm going plexi. i'm gonna use the weldon that has the consistancy of maple syrup or something. i'm thinking i'll bond as much as i can, fill as many gaps as i can, and if anything doesn't seal 100%, i'm just gonna run silicone around the seams. i mean, the weldon is mainly for bonding the plastic, not for making tight seals. i mean, ican make a really strong bond, but it might leak a bit right? so i'll just fill the gaps.

Also, how easy is it to sand plexi? cause even though dreleming the edges to a 45 degree angle would be faster, i dont think it'd be accurate. so i'm thinking of just getting a sandpaper block or something, but only if it's fairly easy to grind away the plexi. is it?

also, i've run across some more measurment problems. i'll update with a better template by tomorrow. looks like i'll have to add another piece. not to mention i ned to extend the front, then i need to recalculate EVERYTHING for 1/4" thick plexi. i have it figured out how, but it;s still gonna be a bitch...

man, it's times like these you're either glad you payed attention in geometry glass,or you curse the heavens for not.

right now, even with my best efforts, i can't seem to figure out a 2 degree discrepancy in my angles. it's like something out of the twilight zone. i have a four sided polygon i'm trying to measure the angles of (it's nearly rectangular). from top left, going clock wise, the angles are 82, 100, and 90. the bottom left one is the mystery spot. drawing a line between the 100 degree corner and the X corner, the 100 degrees is split up into 60 on the top left side, 40 on the bottom right. the top left triangle is therefore 82 + 60 + x = 180. x = 38. the bottom right triangle measures 40 + 90 + x = 180. x = 50. 50 + 38 = 88 degrees. everything seems fine right? wrong. the bottom edge that meets the 90 angle continues onward to create the bottom edge of a rectangle with 4 right angle corners. i donno if you can picture that, but that means that the X angle is now both 88 degrees (according to my math) and 90 degrees (according to the rectangle adjacent to the polygon, whichshares the same bottom edge and middle edge, meaning right edge of the rectangle, and left edge of the polygon). 2 degrees, that's it, and i cant find it. i mean, the joining portion between the rectangle and the polygon is a little off (they're two seperate pieces bolted together with screws) but not a whole 2 degrees off. it's annoying as hell, because i'm trying to make these measurments as accurate as possible.
 
plexi sands very easily, this is related to how easy it is to scratch. The easiest way to get a perfect 45 degree angle is with a bench sander, but in lui of one of those, some heavy duty files and coarse grit sand paper on a block should do.

Is there any reason you choose to make 45 degree angles over straight edges?
 
Elleric said:
Is there any reason you choose to make 45 degree angles over straight edges?
Click to expand...

well, the thing is, the measuring process for this thing has been trouble enough, and i donnoo what kinda mess i'll get into trying to compensate for 1/4" thick plexi. so i'm thinking, worse comes to worse, and i order the panels w/o compensating, i can still put the panels together, edge to edge, if they all have inward 45 degree cuts.


Elleric said:
you peeked my interest, along with my pre-existing interest in working with plexi glass....

i found this today while avoiding doing actual work, its a really good read:
http://www.cichlid-forum.com/articles/diy_acrylic_aquarium.php
Click to expand...

oooh..that's cool. he has a good tutorial about weldon application. though i donno about the pin method.i mean, once the pins come out, is the weldon in between viscus enough so that it wont just drop and squish the weldon over hte edges? and will it be liquid enough to fill the gaps the pins left? hm. we'll we'll see. thanks for that link. should prove to be very helpful
 
the idea behind the pin method isnt to prevent those things, its to allow you to spread the weldon over the entire area of the joint when using larger joints. If your plexi is only 1/8 of an inch thick then capilary (spelling?) action will be sufficiant, but if you have thicker plexi then the weldon might not flow through the joint enough. the pins let the stuff flow and settle in all over, then you remove the pins and allow the pieces to touch to finish the bond, You have 20-30 seconds from application to remove pins and join pieces.

the Weldon he is using has the same viscosity as water, it will *not* fill any type of space what-so-ever on its own. Even the space created by the pins (which actually wont be maintained because the base acrylic will soften and the pins will sink in if you dont remove them in time) will not be filled by this.

When i try to join thicker sheets along longer joints my method is different. i place the 2 pieces where i want them to be and use blue painter's tape on the outside of the joint. I use blocks of wood on either side to help ensure a 90 degree angle later and then using the tape as a hinge move the top piece back to expose the entire seam. this is joining pieces like =|| rather then having the 45 degree edges.

side note: to make it so it will fill joints, take a few acrylic shavings and mix it with the weldon to achieve the desired thickness. This can be used as a structural adhesive in a pinch.

-El
 
alright, well i made a much better cardboard mock up this time around. i'm marking it for 1/4" think plexy, and i'll remeasure. there are only a few parts that might give me some trouble while moving everything around so that they fit with the new thickness, but i think it'll work fine. i'll start taking pictures. i'll prolly make a work log once i get a quote from the plastics guys.

also, considering i'm back to plexi, i'm still looking for good plastics stores to look at.
 
Since the tank wont be very high, you can use extruded plexi, which cost much less then cast.
If you are going to try the cuts yourself, then the best way is to find a plastics dealer in the area and buy scrap (SUPER cheap)... but barring that (there arnt any around where i live so im sol) lowes and homedepot will be generally affordable and will avoid shipping cost.

If you want to have them cut by a pro, then you are pretty well stuck with a much more limited selection...

www.usplastics.com
www.tapplastics.com
and
www.e-tplastics.com

are the places i have used with no complaints about service. I know you said you went to taps, if you have one close enough to pick stuff up at, thats your best bet, what you save in shipping will be worth it. For something like this, i would guess the sheet are going to run you ~$80-100. I doubt they would cut any scraps you buy, but it might be worth asking about since the scraps are so cheap, even if they charge you for the cuts it might be less $.

BTW, continued on, got a fish to put in that little bucket:
sushi.jpg

his name is Sushi. I had forgotten how much fun fish are, I am definatly going to incorperate something fish related into my next case! but im gonna see how yours comes out first (is scared)
 
ha ha, nice. glad iinspired you to build a little tank of your own. for a scrap project, it actually turned out pretty neat looking. let's just hope mine works out in general :p

thanks for the websites. i'll be sure to check them out. though i think i'll be using them to locate nearby stores, since my dremel skills suck and i dont wanna risk it.
 
You must log in or register to reply here.
Back
Top