Working with Acrylic...feel free to ask me any questions.

[ER9]

hey all. i'm a fellow aquarium enthusiast and have alot of experience working with acrylic. if anyone has any specific questions regarding fabricating with it...feel free to ask. i will try to make it to this site on a regular basis to answer any that might be asked. please dont be offended if it takes me a few days to reply as sometimes i can get busy. -ER

[SantaMonica]

Welcome. Nice to have acrylic experts

[nickq]

Hi, I am a total acrylic novice, can you help with the following quesions please?
I want to segment a small glass tank as a sump and think acrylic is probably the easiest way to go.

1. What thickness would you recommend? The largest panel I need is 230mm x 243mm.
2. What type of acrylic? I've seen cast acrylic, clear XT???
3. Can I silicone acrylic to glass?

Thanks,
Nick.

[dohn]

How do you join acrylic to acrylic. Like a T

[nickq]

I think we lost ER9.
Any other Acrylic knowledge out there?

[ER9]

Hi, I am a total acrylic novice, can you help with the following quesions please?
I want to segment a small glass tank as a sump and think acrylic is probably the easiest way to go.

1. What thickness would you recommend? The largest panel I need is 230mm x 243mm.
2. What type of acrylic? I've seen cast acrylic, clear XT???
3. Can I silicone acrylic to glass?

Thanks,
Nick.

sorry for my late response. been a hectic week and 3 days with no pc as new harddrive install didn't go so smoothly.

so i'm assuming you plan to use the acrylic simply as dividers within the glass tank? if i understood you to mean that then you should be able to get away with 1/4" plexi with no problems. in this situation i wouldn't think the quality of the plexi would be much of an issue since there would be little real pressure exerted on the pieces. silicone works reasonably well on plexi. not as strong as glass to glass bonding but should hold up well in situations where there would be only moderate pressure.

[ER9]

How do you join acrylic to acrylic. Like a T

i'm not sure if your asking for technique or glue. if its glue...acrylic to acrylic bonding is best done using solvent to weld the two pieces together. weld-on corporation sells most of the commercially used brands today. their #4 solvent is a decent one to use. most good acrylic solvents (the better ones) have high methylene chloride and trichloroethylene (not sure i spelled those correctly) content. unfortunatelly if you live in some states, especially california, you can no longer get them due to recent environmental regulation changes. if your not in california you can still order them online and have them shipped or visit a local plastics shop if you have one. alternatives would be pure methylene chloride solvent or like i mentioned weld-on made products. there are other companies that make them...i would look for acrylic solvent in any descriptions when looking for one to glue plexi to plexi.

you can also use many of the hardware store general purpose glues for plastic. most all will work fine. the drawback is they will not be as strong and you usually sacrifice alot of aesthetics when using them...meaning they may leave chalky residue etc....
these cheap hardware store glues should never be used in situations where quality glue joints are critical. for example any time you are trying to get strong watertight seams that will be under pressure.

for technique....its best to try and glue one piece so its situated on top of the other piece to be glued to. the solvents are water thin and will easilly run out of the seam your trying to glue. time spent preparing and setting up the two pieces so they are stable and squared will be invaluable. for example in pic i'm gluing the smaller piece to the larger against a 90degree backstop to align and stabilize it.

[worley]

I've seen some examples of people leaving 1/2 to 1" extra, over-sizing each piece then cutting off the excess once glued.
Is there any good reason for doing this?

[ER9]

I've seen some examples of people leaving 1/2 to 1" extra, over-sizing each piece then cutting off the excess once glued.
Is there any good reason for doing this?

yes. its better to leave a much smaller amount though. its hard to see in the above picture but i'm actually leaving about a 1/16th inch overhang on the bottom piece. the reason is that its difficult to make a box correctly using pieces that are the exact size of the finish box dimensions. there are a whole host of problems you will encounter when making boxes commercially that will ruin their sellability. the biggest is solvent run. the solvent is so thin that it will run everywhere if not carefully contained. if you glue two edges exactlly edge to edge solvent will drip over, run under and melt the bottom piece, ruining it aesthetically. the other main issue is precise dimensions. acrylic is generally not a flat material and often is slightly bowed. in the above photo you can see i force it against a backstop with the weights to keep it flat. at the bottom of that backstop there is actually a 1/16" underhang. we cut material slightly larger to compensate for the underhang. when the box is completed we route off this edge. it ends up being much cleaner aesthetically in the end as well.

[worley]

Thanks, knew there had to be a good reason for it ;-)
How about cutting the sheets? Yes, I'm a completely acrylic noob :lol: