Jump to content

Posted Image

PCS & Stuart M. Grant - Cichlid Preservation Fund - Details here

PCS Photo Comp 2018 - Enter to Win Prizes - Details here

July PCS Meeting  - Cichlid Diseases with Dr Richmond Loh - Tues July 3rd - Details soon

July Fish of the Month - Hemichromis guttatus - Details soon

June Photo Comp - Aquarium Plants - Enter Now! - Details soon


Acrylic 101

diy Acrylic fabrication

  • Please log in to reply
15 replies to this topic

#1 BigSkip

  • Forum Member
  • Joined: 22-October 15
  • Location: St James

Posted 26 October 2015 - 11:14 AM

Hey guys, i have a few spare minutes at work so im going to start up a series to help teach everyone about the use of acrylics and how to get the best out of them (to the best of my knowledge). My aim for this series of threads is to help make high quality acrylic work acessible and acheivable with common and reasonably cheap tooling.


First, a bit of background, I am a first class fitter and Machinist currently employed to manufacture experimental equipment used in reasearch and education. Alot of which involves some fairly high end acrylic fabrication work.


So What is Acrylic?


'Acrylic' is a collective term used to discribe a group of glass like thermo-plastic resins made by polymerizing ester of acrylic or methacrylic acid.Usually polymethyl-methacrylate.


Acrylic as it is commonly sold is a a cast or extruded product composed of Acylic Polymer, sometimes with additives (colours, uv-stabilisers etc). A polymer put simply is a plastic, getting its name frome the molecular structure displayed by plastics, Long chains of molecules joined and interlocked together.


In the manufacture process there are two main ways of acheving the desired profile for products, Extrusion and Casting. Extruded Acrylic products are cheaper due to much faster production methods but arent quite as strong as the cast material, but its reasonably close.


Why use Acrylic?



  • Weight - Acrylic is much lighter than glass, making it easier to move large tanks made from acrylic (most of the weight of a full tank is the water, substrate etc. So only comes into play when tank is empty)
  • Impact resistance - Although a very sharp blow will crack acrylic, its impact resistance is in the order of 10 times that of glass.
  • Shape - Acrylic is easily moulded in custom shapes with out the use of extremely high tempretures.
  • Strength - Acrylic tanks require thinner materials to hold the same water weight, so thinner acrylic is needed then if glass were used.
  • Refractive index - The refraction of light through acrylic materials is very close to that of water, so less viewing distortion will happen when viewing the tank from an angle.
  • Clarity - Acrylic is clearer than glass so gives a better veiw of the true colours of the inhabitants, although some acrylic yellow slightly with age, if cared for well this shouldnt happen for many many years.



  • Cost - Acrylic is more expensive than Glass, This is due to it being a petrolium based product, as aposed to glass which is silicate (sand) based.
  • Rigidity - Acrylic is more flexible than glass so needs more support under the tank and bracing at the top to prevent bowing and joint failure.
  • Scratchability - Acrylic is scratched much more easily than glass, although scratch repair in acrylic is significantly easier and requires less specialty equipment


What tools are needed for Acrylic work?


Basic Tank construction can be performed with a circular saw, a hand drill, a router, a good straight edge and a sander. In the posts to following you may see me using some much larger and more expensive peices of equipment, this is to acheive the best possible result, as some of the equipment will be used for scientific reasearch, for a hobbyist hand held powertools can work fine.


How is Acrylic sold?


Acrylic is usualy sold in Sheets and in lengths of Tube.


Sheet sizes are usually 1220mm X 2440mm, in thicknesses of 1mm, 2mm, 3mm, 5mm, 8mm, 10mm, 12mm, 15mm, 20mm, 25mm and upto 300mm (that would be a hell of a tank to need 300mm... hell of a budget too)




Tube is sold in length of 1M or 2M, in lots of diffrent sizes. It is dimension based on the external diameter and wall thickness, Wallthickness being the width of 1 side of the tube. Diameters can be from 3mm upto 2M.




How do i Size Acrylic?


There are alot of calculators online for working out the thickness of acrylic required. probably the easiest to use is the GRAF tank builder; http://www.garf.org/tank/buildtank.asp.

All of these Calculators assume the use of solvent cements with imperfect joins, so if you use the stronger more expensive glues you can get away with thinner acrylic, but at your own risk.


How do i join Acrylic?


The use of acrylic dictates the use of specialist glues, though some expoxies may adhere to acrylic, its no very well and will be pretty ugly. Silicone is a definate no-go as it will just peel straight off. Below are 3 of the Adhesives i commonly use in my acrylic fabrication work.



Here is a quick run down and pros and cons of each;


Weld-on 3 (Back Right):

A Dichloromethane based solvent cement. It has a medium Joint Strength. This is less of a glue and more of a Chemical welding agent. It works by chemically melting the acrylic and then eveaporateing away, leaveing the join to reharden as a solid joint. Adhesion time can be slowed by the addition of small amounts of Acetone.


Pros: Cheap.

Easy (with the right technique, will post a thread on that soon).

Sets within minutes, full bond strength in 24-48 hours (depending on joint width)

Cons: Messy if not carefull.

Only a medium joint strength.

Very little working time after application.

Requires extremely carefull edge preperation


Acrifix 192 (front and center):

A single part UV polymerising cement. Provides a medium bond strength. can be used to fill gaps and on slightly uneven edges. It is an acrylic monomer suspension with a uv activated cataylist


Pros: Fills Gaps

very attractive and highly transparent bonds

apply straight from the tube, no applicator needed

Edge prep can be a little rough

Cons: Price, Aproximately $15 a tube

Requires a bright UV light source to set

Takes 2-3 hours to set even with high power uv source, Full hardness in 2-3 days.

Can be very mesy if not very carefully.


Acrifix 190: (rear left)

a two part polymerizing adhesive. very high bond strength. provides near invisible joins and is the highest strength acrylic adheisive i know of.

Pros: Very strong

Can fill large gaps (accounting for shrickage)

very clear joins if mixed properly

Cons: Very expensive, $76 dollars for 1KG of the adhesive (aprox 1.1 litre) and $20 for the catalyst which is required.

Can be very hard to get hold of (my last order through work had to be special ordered from germany and took 8 weeks)

Takes 24 hours to set, 1 week for full hardness.

Smells very strong, definetely needs good ventilation when using it.

Special edge prep required for best joins.


How do i cut Acrylic?


While at work i actually use industial tablesaws and machine tools, not something avaliable to the average fish keeper. although good results can be acheived using the following method;


  1. Leaving the protective layer on, Using a circular saw and a guide rail (a straightish peice of wood will do) Cut all your peices slightly oversize (5mm or so) as the saw will heat up and 'gall' the surface, leaving a rough opaque white finish) Spray the saw blade with a thin oilbased lubricant as much as possible (WD40 works great) if you are game you can spray water on it to help keep it cool, but with electric powertools its not the best idea.
  2. using a flush trim bit in your router, align your straight edge with the final size of the panel and run the router along the edge is a smooth and consistent fashion. BigSkip tip: If you wrap a small amount of masking tape around the bearing on the flush trim bit you will cut ever so slightly off the final size, remove the tape and take the very light pass to finish, this will minimise heat build up and should provide a better edge
  3. repeat for all sides.
  4. DO NOT POLISH EDGES TO BE GLUED. this will cause 'crazing' (a spider web of micro crack across the surface, severly compromises the strength of the material)
  5. Remove a small amount of the protective coating to alow gluing, leaving as much as possible until the tank is complete TEAR THE COATING WITH A STRAIGHT EDGE, DO NOT USE A KNIFE TO SCORE IT. this will score the acrylic and cause headaches later.

How do i Drill Acrylic?


Although Acrylic can be drilled with unmodified drill bits, it can grab and pull the drill in, cauing alot of damage it the material, and can also chip where the drill is exiting. The Ideal way to combat this is to use a drill with a special point. The point angle on Most drill bits you buy is 118 degrees, for acrylic the ideal angle is 60 degrees (think of it as a much sharped point on the end) Also the rake angle need to be reduced to 0 degrees or very close, Exactly the same as is done with Brass. Reducing the Rake angle is more important than the point angle. a 118 degree point with 0 rake will still provide good results. See the below diagram for what this all means and the video on how to easily reduce the rake angle. Another major thing to keep in mind is it all has to be kept very cold, keep spraying water mixed with a small amount of detergent and run the drill fairly slow. this will both lubricate and cool the material to prevent galling of the hole.






How do i Finish the edges?


finishing acylic edges can be done in several ways, my preferred way and they method i believe provides the best results is to sand them upto 1500 grit, them use some micro mesh pads upto 12000 grit and finish with a light buffing.


Another common method is Flame Polishing. This requires care and a hot blow torch (the yellow one, blue isnt hot enough) or an oxy acetylene torch. its as simple as passing the flame quickly along the edge. This melts all the tiny micro cracks that cause the opaque look back into one smooth surface, but be carefull it is very easy to burn the acrylic and turn it brown. Also, any roughness in the surface will remain, saw marks will still be visible, just shiny.





Thanks all.
In the next post (when i can find time to make some photos etc) i will go more into the use of the 3 diffrent glues i discribed and show the processes of building a basic box from acrylic.


ADMINS: Am i able to link to suppliers of acrylic and adhesives that are not forum sponsers?


Edit 2: Damn it.... cant even spell edit right

Edited by BigSkip, 26 October 2015 - 02:58 PM.

#2 BigSkip

  • Forum Member
  • Joined: 22-October 15
  • Location: St James

Posted 27 October 2015 - 11:00 AM

Use of Solvent Cements.


So next up is a quick guide to the use of Solvent Cements to join Acrylic. This is probably the easiest method for making a tank, and with a little practice and patience you can produce very attractive joins with a medium strength. This is the method that Online Tank calculators assume you are using, and allow for a not so flash attempt at it. So a good join on a tank using the recommended thickness will be plenty strong for an aquarium.


First a quick bit on Safety: The active ingredient in Acrylic Solvent cements is a Chemical called Dimethyl-chloride. While the fumes of this chemical are pretty harmless with reasonable ventilation skin contact should be avoided where ever possible. It is suspected of being a chronic contact carcinogen (skin contact can lead to cancer later in life). Nitrile gloves will keep you safe, and are reasonably easy to get hold of.


How solvent cements work:

Acrylic, like all polymers (all plastics plus a few others) are long chains of molecules, often thousands of molecule long. these wind together and form the material we see. Solvent cements (and some other solvents, avoid cleaning with anything but soapy water and isopropyl alcohol) act on the acrylic by breaking up the polymer chains in to monomers, or single molecules. This melts the acrylic and causes it to swell slightly. Once the solvent is removed, evaporated in our case, the monomers actively try to re-join into polymer strands. Resetting the melted acrylic into a solid form. Dimethyl-chloride is also thinner than water in it’s consistently, this allows it to be 'wicked' into the join. Basically put, it pulls its self into the join if the gap is small enough.


Solvent cement Applicators:

There are 2 common method for applying solvent cements to a join. the most common is an applicator bottle, a small poly-ethylene bottle with a needle attached to the top (usually blunted). the applicator bottle is used where large joins in thick materials are needed. It allows a lot of cement to but laid down very quickly, at the cost of control. For aquariums this is the method I recommend.




The second method of applying the cement is the use of a syringe. This method allows much more more control, but sacrifices speed. I only recommend this method for small joins in thin material.




Using an Applicator Bottle:


There is a little trick to using an applicator bottle. if you just tip it over and squeeze you will end up with solvent everywhere (more on why this is bad later). The best way to use an applicator bottle is to only fill it a third full. Squeeze just over half of the air out of the bottle, and as you tip the bottle slowly release some of the pressure, the action of drawing air into the bottle will stop solvent coming out. When the needle is on the join and ready to add some solvent lightly squeeze the bottle. Once you have added all the cement you need to the join lightly start releasing pressure from the bottle and return it to upright.





Edge preperation:

The smoother and Flatter the edge to be joined the better. As i quickly started in the last post a router can do a good job of this, if you want to be extra sure you have a flat and smooth edge here is what i do. Using some double sided tape i attach long lengths of sandpaper to a straight edge. I use a coarse 80 grit on one side and 240 grit on the other. The longer the straight edge the better this will work, Long box levels from Bunnings work great and are pretty good for straight. Using your finger as a guide and to stabilise the tool, run it lengthways along the join holding it as square as you can, first with the coarse and then with the fine. If you want you can colour the edge with a marker to see where you’re high and low spots are, just make sure to clean it all off afterwards or it will colour your join.


It should look something like this;



Gluing method 1: (least recommended)

The method you will find most places on the internet is the following: Place the pieces of the tank and using electrical tape apply a small amount of pressure on the joins. run your applicator along each side of the joins allowing the solvent to wick in. leave for a while and hey presto!.




The major issue with this method is that it rarely produces full width joins, often leaving voids in the middle. These defects can greatly impair joint strength and they look ugly. Hopefully you can see what I mean below (taking photos of things that are really clear is hard :P)


This photo was taken only minutes after the join was made, the defects become worse as the acrylic settles to back to its final volume, shrinking a little.


Gluing method 2: (most recommended)


This method is known as the 'wire method' it produces much better and more consistent joins but is a lot more setup and for large tanks you will probably need a helper (you will hear why in a second). This method involves putting thin wire in between the join during the initial setup. Adding the solvent, waiting and then removing the wires. This allows all of the air to escape the join as there is a much greater gap for it to do so, and also the increase in volume of solvent allows for a longer exposure to the acrylic before evaporating.


To start you are going to need some thin wire, i actually use the old 8amp fuse wire, available for next to nothing from Bunnings, with a small bend at one end. The small bend is just to make it easier to grab with some pliers when it is time to remove it.



One of these wires is placed every 150mm. gently pulling on the wires, make sure they all have even drag on them, is one is noticeably less than the others small wooden wedges or shim should be placed under the sheet of acrylic until it is even. This is to even out the gap between the two pieces of acrylic to ensure the best join. The better your edge prep the easier this will be.



Apply your solvent, add enough to completely fill the void (don’t worry it will be easy to see with the protective coating peeled back a bit) adding enough to be visible on either side doesn’t hurt either. Wait 30-45 seconds then remove the wires one by one. Apply light pressure down while trying to keep everything in place; they will want to slide around a little.


After a few minutes your join will set. Leave it for 15-20 mins before trying to move anything just to make sure. As you may be able to see below the join is free from voids in the centre and looks much clearer (there are small bubbles around the side due to low pressure on the join. the test pieces weighed next to nothing, with the weight of a full panel behind it this won’t be much of an issue)



BigSkip Tip: Adding a small amount of acetone, 5-10%, will slow the setting of the solvent cement by a little while, giving a bit more time to work after applying it.




you will end up scaring the acrylic and you will have to sand and polish the mark out. below is a deliberate spill to show you why.




Un fortunetly the next installment may be a few days away, due to setting times for the glues, but enjoy for now, let me know if you have an questions.


Cheers, Skip

Edited by BigSkip, 27 October 2015 - 01:08 PM.

#3 Holy22

  • PCS Club Member
  • Joined: 05-September 14
  • Location:Halls Head
  • Location: Halls head

Posted 27 October 2015 - 11:19 AM

Fantastic thread, thanks a lot bigskip

#4 Rovik

  • PCS Club Member
  • Joined: 12-July 10
  • Location: Bullcreek

Posted 27 October 2015 - 01:59 PM

What a fantastic write up, thanks for sharing your knowledge With us. Think this one deserves a sticky !!

#5 BigSkip

  • Forum Member
  • Joined: 22-October 15
  • Location: St James

Posted 21 November 2015 - 11:53 PM

Part 3: Polymerizing Cements and Tank Construction


Apologies for this part taking so long, my partner hasn’t been well and so I have been snowed under with that and work. But better late than never.

In this part I will cover the use of polymerising cements and my recommended procedure for tank construction.

What is Polymerising Acrylic Cement?

Acrylic polymerising cement is a type of acrylic adhesive based on Acrylic monomers suspended in a solvent with a polymerization catalyst. Simply put, its thick glue that dries into solid acrylic material. There are two main types of polymerising cements; UV Curing and 2 part adhesives. Both have their own advantages and disadvantages. UV polymerising adhesives are usually very aesthetically pleasing and relatively easy to use. The two part type tends to have high strength and a longer working time. But much longer time to fully cure.


Also Polymerising Adhesives Shrink as they cure, so when using them allowances have to be made to compensate for the effect this can have on joint stresses and joint distortion.

In the following examples I use UV polymerizing cement, but the procedure is pretty much the same for the two parts, Except for the mixing and use of a separate applicator bottle.

How do I use Polymerizing Cements?


Polymerizing cements can be used in a number of ways, they can be used in the 'traditional' method of gluing, applying to both or one face to be joined and then pressing together, but this looks ugly and isn’t overly accurate. Below I will walk you through the process I find gives the most aesthetically pleasing result while also being very strong, although more advanced tooling is needed then when using Solvent cements.


Edge Prep: When using polymerizing cements edge prep is very important. Not as much the smoothness of the cut, but the straightness and the angle. Unlike when using solvent cements we want a slight angle on our edges, I like to use 5-6 degrees, but anywhere for 3-15 can also work. Below is an example with 15 degree edges to make it easier to visualise.


IMPORTANT: When cutting sheets to glue into your tank, how it will be constructed is very important. Some pieces need to be cut oversize. I cut the base 40mm over size on both dimension and the front and back oversize on the horizontal direction by 40mm. you’ll see why later.




Please note that a rough finished surface is ok for this kind of adhesive, I glue it straight off the saw with no additional preparation.




The next step is what allows this type of cement to be a lot more accurate than solvent type cements. Mark a like on your joined piece based on the inside edge of the join. Use a Metal working scriber (or a pointy metal stick, same same) to score a straight line, square to your edges.




Why did we do that? Well, look back at our edge prep photo, see that pointy bit? That will slide and nicely locate its self in that scribed line, so if you’re scribing is good, your tank will be quite accurate.


Locate the piece in the scribe mark and find something to hold it square, I have some pieces of Ply wood cut at 90 degrees with a 45 chamfer on one side. I use these with double sided tape for smaller fabrication jobs, bigger projects I make up more elaborate holding method, but anything that will hold it at your desired angle will work.




Here you can see the assembled joint before masking the ends and applying the glue (the edges are rough as this is a demonstration on scrap pieces)




Add some Sticky tape to the ends of the join. Try to 'Bulge' it out a bit, to allow for some shrinkage material.




Next apply the adhesive, don’t be shy. If you apply to little you will end up with a concave join, we want plenty of material left after wards for routing and polishing.





The adhesive will slowly pull its self into the join and fill the cavity. If your cut was nice and straight there should be no leakage on the back side of the join, if there is, leave it to dry and sand and polish it later.


After the adhesive has pulled into the join its time to let it cure. As i'm using UV activated cement I put some UV lights around to cure it. I have some special T8 tubes I use at work, but UV party lights and even regular fluros work as well, they maybe just take a little more time. It’s important to note that I place the lights at the back of the join, this sets the glue in a way that provides it with the ability to pull more cement in from the excess outside the joint to compensate for shrinkage. If you put the light source on the outside of the join you set the excess first and it starts to pull adhesive from the join out to compensate, leading to shrinkage bubbles, Which severely compromise joint strength..


Once the Adhesive has cured fully (allow several days to completely harden) Trim the oversize edges with a flush trim bit in a router and then sand and polish (I’ll do a post on this soon)


After wards you will have a very strong and (if you don’t have bubbles) Invisible joint.





Tank Construction:


Below is the procedure I use when fabricating a tank, I find it works very well for me and I always see good results.


Lay your Back piece out with the outside facing down. Prep and attach your two sides. Making sure the bottom edges are aligned.



Note: the bar across the top is to try and minimise Shrinkage distortion, as Polymerizing cements shrink when they cure they tend to pull things out of square, just like with welding. As the join is thicker on the outside it will try to 'spread' the two side pieces, this is a simple way of minimising this.




Once allowing the adhesive to reach a good amount of curing lay your front piece outside down on your work surface. Attach both sides at the same time, making sure to align the bottom edges the best you can.



finally lay your bottom sheet down and attach the rest of the tank all in one go.



Trim and polish (Will do up a post about sanding and polishing acrylic soon. but not 100% sure when)

And there you have it, using polymerizing cements and tank construction. These two methods with a good sanding a polish produce very attractive and strong Tanks. As shown below. This tank is a bit of an odd size as it’s for a specific project I have going on. But as you can see it’s very clean and professional. Although I may add some top braces before I put it into action.




#6 dicky7

  • PCS Club Member
  • Joined: 25-October 13
  • Location:Perth
  • Location: Noranda

Posted 23 November 2015 - 11:26 PM

Thankyou this is very interesting

#7 69olds

  • PCS Club Member
  • Joined: 03-November 07
  • Location: Esperance Western Australia

Posted 04 November 2016 - 10:55 AM

Really well written post and very easy to understand look forward to reading more

#8 LexAgate

  • Forum Member
  • Joined: 03-February 15
  • Location:Perth
  • Location: Mount Lawley

Posted 06 November 2016 - 09:41 AM

Words can't describe how satisfying this join is!!!

Sent from my iPhone using Tapatalk

#9 tropheus

  • Forum Member
  • Joined: 29-November 04
  • Location: Osborne Park

Posted 03 February 2017 - 10:12 AM

ADMINS: Am i able to link to suppliers of acrylic and adhesives that are not forum sponsers?

I didn't see an answer to this. A list of suppliers would be really useful, and I can't see that it would be an issue...?

Sent from my iPhone using Tapatalk

#10 Jules

  • Forum Member
  • Joined: 07-July 09
  • Location: Baldivis

Posted 03 February 2017 - 11:02 AM

I for one am looking to upgrade my 7x2.5 to acrylic possibly, can you PM me the companies that could give me quotes for an aquarium that size?


#11 tropheus

  • Forum Member
  • Joined: 29-November 04
  • Location: Osborne Park

Posted 03 February 2017 - 11:19 AM

I for one am looking to upgrade my 7x2.5 to acrylic possibly, can you PM me the companies that could give me quotes for an aquarium that size?

I'm not sure what happened but I was quoting from one of Bigskips posts...

I would love some info on this. Having details of suppliers for DIY projects shouldn't have any effect on forum sponsors, so hopefully we can get details for suppliers for this (and other projects)

Sent from my iPhone using Tapatalk

#12 Hood

  • PCS Club Member
  • Joined: 06-February 08
  • Location: Clarkson, WA

Posted 04 February 2017 - 02:17 PM

I too would like to know good suppliers of big acrylic tanks. :)

sent from Huawei P9 using tapatalk app.

#13 dicky7

  • PCS Club Member
  • Joined: 25-October 13
  • Location:Perth
  • Location: Noranda

Posted 04 February 2017 - 03:50 PM

I think you will have to import them from China  for the Big tanks , I have heard that even importing yourself still will work out cheaper than buying here .. don't quote me just what I have been led to believe

#14 BigSkip

  • Forum Member
  • Joined: 22-October 15
  • Location: St James

Posted 06 February 2017 - 07:19 AM

There Are a few places in perth that can make big Acrylic tanks. I would buy from them if i were to buy one, just because they will offer a warranty of sort, which you wont get from china.

#15 BigSkip

  • Forum Member
  • Joined: 22-October 15
  • Location: St James

Posted 03 June 2017 - 06:14 PM

Just thought id make a 'show off post'. This is an example of the kind of things I do at work with acrylic, although i actually work with metals mostly.

This is a prototype that never got commissioned. I cant say what its for, other than filtration research and its upside down in these photos.




#16 werdna

  • Admin
  • Joined: 10-March 07
  • Location: Coogee

Posted 08 June 2017 - 02:02 PM

ADMINS: Am i able to link to suppliers of acrylic and adhesives that are not forum sponsers?

I didn't see an answer to this. A list of suppliers would be really useful, and I can't see that it would be an issue...?

Yep, no worries

Also tagged with one or more of these keywords: diy, Acrylic, fabrication

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users