# Acrylic fabrication - I can help



## MiamiAG (Jan 13, 2004)

Acrylic fabrication is something that I really enjoy. I am by no means an expert, but I have worked with it quite a bit. I have made calcium reactors, protein skimmers, overflows and sumps. This is an image of my calcium reactor that I later turned into a canister filter/CO2 reactor combination.

Anyway, following in the tradition of Dennis' great woodworking thread, if you have any questions or need help building things out of acrylic, please post them here. I and others will try to help. I'll post my work here as well. I'm currently working on a protein skimmer.


----------



## Sir_BlackhOle (Jan 25, 2004)

Cool! I would like to learn about working with acrylic. Maybe even build my own tank one day...


----------



## MiamiAG (Jan 13, 2004)

It actually is really easy once you get the hang of it. Just need a few good tools. Specifically, a good router, router table and a table saw.


----------



## dennis (Mar 1, 2004)

Art, great idea. Thanks

Could you maybe give a few quick points or basinc info about working with acrylic. Maybe a quick little cheat sheet of the tools and different materials, joinery methods, etc. I have been meaning to do this for hte woodworking thread but life is not being kind lately

Thanks fopr starting this.


----------



## bharada (Apr 17, 2004)

Is there any structural reason to not make an acrylic tanks with five flat pieces as you would with glass? You only see acrylic tanks that have the front and sides formed from a single bent piece, which adds a lot of complexity for the home DIYer.


----------



## MiamiAG (Jan 13, 2004)

Dennis, I'll do that. Little later today though.

Bharada, most acrylic aquariums are made from 5 flat peices. There are a number of acrylic manufacturers that bend a piece of acrylic to create curved edges of bow fronts. I don't recommend that a hobbyist do that as it requires large ovens to achieve a bend in large 1/2 inch thick acrylic.

You can bend thinner pieces using a heat gun of heat tape, but this is more of an advanced technique.

To build an aquarium, use 5 flat pieces.


----------



## bharada (Apr 17, 2004)

Thanks Art. Seems like all the acrylic tanks I see locally (mainly TruVu) are three pieces (not counting the top bracing) and have a flat front face. But the sides are bent off of the front. The backs are usually colored acrylic.

I know how hard it can be to get a good bend using a heat strip. I used to fabricate assembly fixtures and molds out of acrylic in a long past job. The thickest material I ever worked with was 1/4" so I can't even imagine how hard it would be to try bending a 1/2" sheet with DIY equipment.


----------



## MiamiAG (Jan 13, 2004)

For those of you contemplating building something out of acrylic, here are some tools you'll need.

1. Router, router table, good acrylic router bits
2. Table saw with a good acrylic blade
3. Glue: Weld-on #4. No. 40 for certain applications
4. Pins or thin wire
5. Some sort of flat weight. I use bricks wrapped in duct tape.

That's it. The rest is up to your imagination.


----------



## dennis (Mar 1, 2004)

Thanks Art.

I have 2 more questions though. First, what traits would a good acrylic router bit or saw blade have? I am assuming the bit would be a sharp carbide spiral bit and the saw blade would be a ATB (alternate top bevel) but I could be wrong. Also, what are good bit and blade speeds for working with acrylic?

Thanks


----------



## MiamiAG (Jan 13, 2004)

Dennis,

Really depends on how much acrylic work you're going to be doing. For a one off project, good carbide blade or bits meant for fine cuts would work.

If you are looking for a good cut that won't cause melting, you need to look for acrylic specific products. For blades, look for triple chip with a negative rake. I bought a Freud for about $90. It has a triple chip grind, 3-degree hook and .110" kerf. You are looking for 60 - 80 teeth.

Same goes for router bits. Carbid buts will work for one-off projects. Specific acrylic bits from Unsrud if you are going to do more than one project.

As far as speed is concerned, anywhere from 6,000 to 14,000 ft/min is what is required. Based on my blade, I'm at 9,000. However, I've found it just as important to feed the piece at just the right speed. Not to slow or too fast. You get the feel once you practice a bit.

At the end of the day, you want a good clean cut without chip outs or melting.


----------



## Troy Hendrickson (Jun 20, 2004)

Got any sources for decent prices on sheet acrylic?

I'm quoting an aquarium for a customer built into the end of a bar, 24"L X 24"D X 18"H, I've built several of these in glass but quite frankly, I'd like to build the tank in my shop and take it to the job site after I build the column that supports and the weight is getting to be a bit much for a middle aged man :shock: 

It would have a solid surface underneath it supporting the bottom piece and the vertical corners would have 3/4" oak frames covering them to take the minimal load from the top of the column (it actually hangs from the ceiling).

What thickness acrylic would I need in your opinion as well?


----------



## MiamiAG (Jan 13, 2004)

Troy,

Depends on whether you will use a top brace for it or not. I would recommend 1/2 Acrylite GP from Cyro. Here are a few resources for you.

Check out the Cyro Website for good information on building aquariums and calculating thickness.

I've uploaded an Excel spreadsheet that will calculate thickness for you. You can download it at http://www.aquaticplantcentral.com/files/tankthicknesscalculator.xls.


----------



## Aaron (Feb 12, 2004)

Hey Art,

What is the router for? Half lapping/ mitering the joints? Also, I notice you mentioned that the tanks you make use 5 pieces. Do you not use top braces? 

Aaron


----------



## MiamiAG (Jan 13, 2004)

Well, I should have said, the tanks I've seen made. I've not made a tank. The tanks I've seen made are thicker so that you don't need the top brace.

The router is for everything- making holes, finishing edges, rounding over, making O-ring slots, slos for the tubes, etc.


----------



## Daemonfly (Mar 21, 2004)

Ebay has a section on acrylic pieces, most are left over stick from CNC machining, etc... can usually get good deals on smaller pieces.

Also. I'd rather get "Cell Cast" acrylic over normal stuff, as the cell cast is said to be stronger.


----------



## MiamiAG (Jan 13, 2004)

Great points.

If you can strike up a relationship with a local acrylic shop, they will usually give or sell you their scraps. Ebay and other portals also have excess items you can purchase cheaply.

For aquarium use, always go with cast acrylic. Extruded acrylic is cheaper but won't last in an aquarium setting.


----------



## pineapple (May 4, 2004)

For general advice on making an acrylic aquarium, the following link seems to be the best on the English-speaking Internet:

http://duboisi.com/diy/BNdiytank/bndiytank.htm

Andrew Cribb


----------



## MiamiAG (Jan 13, 2004)

Andrew,

Thanks for the link. However, I would disagree with the tools and jigs used in that summary. If you are looking to build an acrylic aquarium, I would refer to ReefCentral's DIY forum.

Tools would include Weldon 4, wire, router, table saw with acrylic blade and assorted jigs.


----------



## pineapple (May 4, 2004)

Art,

That's an excellent source that I have overlooked. I'm still in the learning phase of tank making. More to come if I can manage to put together a reasonable prototype that would be of interest to the Board.

Andrew Cribb


----------



## bharada (Apr 17, 2004)

Art,
Do you have any experience in bending acrylic tubing? What would you recommend I use to keep the tube from collapsing while bending? I know they use springs when bending copper pipe, so is there an equivelant tool used for bending acrylic?


----------



## pineapple (May 4, 2004)

A good question. I very much doubt it is possible without supporting the inside of the tube (which would be hard or impossible to remove after bending). Narrow tubing such as that used for filter intakes and returns is possibly best made with glass since glass can take a good scrubbing without incurring scratches.

Andrew Cribb


----------



## MiamiAG (Jan 13, 2004)

Acrylic tube would not work well for bending. If you need a clear bend I would suggest using clear PVC elbows.


----------



## bharada (Apr 17, 2004)

Well I tried bending a piece of 5/8 OD acrylic tube, packing it tight with fine quartz gravel and heating it over the kitchen stove. By keeping inward pressure on the ends while making the bend I was able to keep the tube from stretching and collapsing around the gravel. I ended up getting a decent bend albiet with some ripples on the inner radius.

Of course, when I tried to drill a test hole in it using a brad point bit it cracked :lol:. I'll pick up an appropriate bit when I go back to Tap Plastics for more tubing.


----------



## gpodio (Feb 4, 2004)

If you're going to be doing several bends, you can invest in bending springs, I have several that I used for bending PVC pipe for electrical work. You just slide them in, heat and bend then pull them out with a string. Very easy and gives perfect bends up to 90 degrees.

For drilling, if you get desperate, just put the new drill bit to a piece of cement for a little while to remove the sharp edges, obviously if you have a grinder use that  Old worn out drill bits usually do a good job with acrylic, as do worn out jig-saw blades. I don't know about drilling where the bend is though, that may get a little too thin and brittle to drill easily, specially if doing it by hand.

Giancarlo Podio


----------



## bharada (Apr 17, 2004)

I tried using a spring (pulled out of a curtain rod) but the acrylic tends to mold itself to the shape of the spring making it near impossible to pull out.

I've got some old jobber bits in a drawer. Next time I'll give one of them a shot.

Thanks.


----------



## gpodio (Feb 4, 2004)

Never had that problem, but never tried regular springs. You usually need to pull them out with a little force but they never got stuck on me. Perhaps the spring you used was a little "stiff", these are very flexible and I'm guessing that when pulling on one end the coild expand making the outer diameter smaller, enough to pull out.

This is a UK site but just to give you an idea of what they look like:

http://www.tlc-direct.co.uk/Main_Index/Conduit_Pvc_Index/Bending_Springs/

Giancarlo Podio


----------



## bharada (Apr 17, 2004)

Well, I anticipated problems with the curtain rod spring as it wasn't tightly coiled like a true bending spring...but what you gonna do when the fabrication bug hits you at 8pm?


----------



## gpodio (Feb 4, 2004)

bharada said:


> Well, I anticipated problems with the curtain rod spring as it wasn't tightly coiled like a true bending spring...but what you gonna do when the fabrication bug hits you at 8pm?


....start tearing down the curtains of course! :wink:


----------



## Gumby (Aug 1, 2005)

I work with acrylic at one of my jobs (making tanks/sumps). Here's the pointers I can offer:

If you can get a wet table saw(stuff heats up pretty well) with a grinding blade, that works well. 

For tanks, building a rim on the top of the tank provides extra support. A support brace is always a good idea if you've got a long tank. Becareful about building tall tanks with acrylic. The taller the tank, the more pressure is put on the seems and panes and you'll have to use thicker acrylic. When in doubt, use thicker acrylic. If the acrylic is too thin the tank will bow. Be 1000% your welds are perfect.

If you can find a local plastics supply company you should be able to get sheets of acrylic at a reasonable price. Bulding supply places might have it as well. 

If you somehow scratch the acrylic, take a heat gun or blow torch to it, the scratch will "melt out."

One last thing to keep in mind: cutting acrylic is very bad for your health, it causes cancer. Wear a mask when cutting.

I'm no where near an "acrylic expert" but the guy I work for is. If you have any questions that Art can't answer, ask me and I'll see what I can find out.


----------



## Osteomata (Jan 11, 2005)

Anyone know what the 1 gallon or 1.6 gallon hex tanks (common in the US sold under various brand names) are made from? Acrylic or Plastic? Does the lack of any seam indicate that it is plastic?

Reason I ask: I am thinking about taking 3 small hex tanks and connecting them via clear plastic swim-through tubes. I would need a good method for cutting holes and a secure method of glueing the tubing into place. Any thoughts?


----------



## alexanderM (Sep 6, 2005)

Where does one get clear acrylic pipe? What is the best way to cut perfect circles for the top and bottom of the calcium reactor? The supplied picture of your calcium reactor looks great.


----------



## niko (Jan 28, 2004)

Better answer late than never.. something like that...: 

http://www.tapplastics.com/shop/product.php?pid=140&

--Nikolay


----------



## SkinniMini (Mar 26, 2006)

Someone earlier mentioned scratches..
I recently bought an acrylic tank & before I filled it, I rinsed it out, wiping it down with a washcloth & noticed that I scratched it! (With a washcloth, for crying out loud!)They are not deep scratches, but noticeable enough across the front of the tank to be upsetting.
Is there any way to get these out? Do I drain it & use a heat gun? 
What is a good way to clean it in the future?


----------



## wiste (Feb 10, 2006)

They sell micromesh pads to restore acrylic aquariums.
They can be found at the site below.
http://www.sisweb.com/micromesh/reference/aquarium-restoral.htm
I just used the kit to remove a scratch on my acrylic aquarium. Works great.
I went with the variety packs and a bottle of antistatic cream.


----------



## wiste (Feb 10, 2006)

I would be hesitant to use a hot airgun or blowtorch on my aquarium.
Using the micromesh seems to be lower risk.

Here is a scratch that I got on my 35 gallon hex during moving.
I followed direction on the site listed. I used 400 grit paper to smooth the scratch.
Always using an up and down motion during sanding. Repeating the process for each of the finer grit pads. Taking pictures with a digital camera with the flash helps identify any scratches too fine to see unaided. Applied antistatic cream when sanding complete.


----------



## steamer (Oct 18, 2006)

I have manufactured acrylic tanks for a couple of years. I have not read the whole of this thread so I apologise for repeating things. 

I am sorry to say that I personally do not recommend making aquariums out of five pieces of acrylic together as I have found that the glue generally runs out of the joint so its easy to get very small leaks if you are not carefull, then you fingd that you are having to add extra adhesive into the corners of the tank which I believe reduces the benefits of using acrylic over glass, which is 1/4 the price of acrylic, in this country anyway. Nice bent acrylic corners will never leak and look more proffessional IMO. An acrylic bender makes much nicer corners and are available for a few hundred dollars but they can be simply made with a long heating element, some steel section and a dimmer switch. 

When attaching the base, first glue thin strips of acrylic along the inside of the base plate leaving 1-2mm gap between the strip and where the side of the tank will sit. When you attach the base to the tank the strips prevent the adhesive running out of the joint. You can also fill this gap with extra adhesive to give the joint extra strength.

Acrylic is so easily scratched and I think micromesh kits are brilliant but they are also expensive for what you get. Polish out scratches with 600 grit, slowly reducing the courseness through 1000 and finally 2000 grit. for the finish use car colour restorer then Brasso and finally silvo silver polish (you can also use a dedicated plastic polish but they are expensive). Polishing Acrylic is a bit of an art and sometimes its easy to leave a milky appearance in the tank if a fine polish is not used. You can also use a plastic diswashing sponge with a plastic mesh cover (25 cents from the supermarket) to get the last few scratches out, before the final polish. Ensure that you wash the tank after polishing as some of the polishes are toxic to fish.

Hope this is helpful

Mick


----------



## wiste (Feb 10, 2006)

> Polish out scratches with 600 grit, slowly reducing the courseness through 1000 and finally 2000 grit. for the finish use car colour restorer then Brasso and finally silvo silver polish (you can also use a dedicated plastic polish but they are expensive).


With regards to sanding, a point not mentioned is that it is my understanding that you should sand in a up and down motion in one direction and not a circular motion to get best results.

Additionally, I recommend you continue to finer micromesh including 4000, 6000, 8000 and finishing with 12000 grit. If you finsih with 2000 grit there will be many fine scratches and would leave a lot of work for the polish.



> I think micromesh kits are brilliant but they are also expensive for what you get.


The kit that I purchased did not seem expesive. I ended up with multiple pads of each mesh and bottle of static cream in order to meet the minimum order requirement of $25. The pads seem to last well if you use them in order and do not make large jumps when going to a finer mesh.


----------

