Acrylic fabrication questions? I can help!

[Floyd R Turbo]

That's why I plan to practice quite a bit on the pieces of extruded that I have laying around that my Dad gave me. I've built filter boxes before but never really paid much attention to technique and materials, now that I know more, I can make them better. Plus I have a bunch of different kinds of solvents/glues to try out. I have #3, #4, #40, and after this weekend I will have my 99.9% MC and 99.7% AA to make my owns, along with a big load of material from Sabic Polymershapes. Best price I've found so far by the way. Plus the one I found stocks Polycast. Good for when I decide to actually build a tank down the road.

So far, I've managed to get through this thread, all the way from the very beginning (03!) and I'm up to about post #200 in this 3rd split. That's 3300 posts so far. Only 1600 more posts to go.

But, it's like any super huge thread, like BeanAnimal's "Silent and Failsafe" 3-pipe overflow system thread, no one reads from the beginning, so the same ?'s over and over. And I'm guilty of it too. For anyone reading this, go way back to the original thread in the archive and read that. No pictures, but the 'meat' of what this thread is all about is in that part before the first split. Really, really, really really great info. After that, you have to search for the good tidbits of advice, which I am copying into a doc as I go so I can sort through it.

I almost want to put together a summary post.

 

[Floyd R Turbo]

**DEEP BREATH IN**

**EXHALE**

I just finished reading ALL of this thread, all the way back to the beginning. That is over 5000 posts, and by far the longest thread I have ever read. I have to say that this is by FAR the best DIY thread I have ever read.

I just wanted to share a little bit of what I learned both here and from making dozens of calls to suppliers and chemical supply companies.

I have managed to find a couple of lab supply, chemical supply, and plastic distributors that carry Methylene Chloride (MC) and Acetic Acid (AA). I had to pull teeth with these guys to get the 'assays' on the MC in some cases, apparently they are not used to so many questions. The AA is easy, because you just need to ask for "Glacial" or "ACS grade" AA and you're good. I found a lab supply house that had a 4oz (125 mL) bottle of it for $9.50 and a chemical supply company that had a 2.5 L of it for $60 - which will be enough to last me a VERY long time, but I won't get that until I run through the 125 mL bottle first.

The same lab supply had MC 99.9% pure for about $9 for 4oz, but Sabic Polymershapes had Caseway SC125 (99.9%) for $5 for 4 oz, so that's what I got. The Chemical Supply place I found the AA at also had 99.9% MC, but it was $60 for 4L (1 gallon!) so that place it definitely my supplier for MC, once I go through the stuff from Sabic.

Unfortunately, before I figured all this out, I bought WO #3, #4, #16, #40, and #2007 (for some PVC). So at least I have a much of scrap acrylic that I can practice on with the WO #3 and #4, and eventually I can try mixing up some #40 and playing with that, and I can then mix up my own using the MC and AA and try that.

I also called probably a dozen acrylic suppliers, and managed to find that Sabic Polymershapes (formerly GE Polymershapes, for those of you that also read this entire thread) that is only a few hours away carries Polycast, and in one case, it's actually the same price as I can get plex-G for locally. Their Plex-G price averaged 25% less than my local shop, no charge to cut in half, and no 'per order' fee like Regal (local).

In case anyone else in searching and wondering if they're getting good prices, as of Friday, here's what I was able to find:

Polycast, 4x8 sheet
3/8" 0.375 true $201
1/2" 0.500 true $323
3/4" 0.750 true $454

Plex-G 4x8 sheet clear
1/4" 0.236 $107
3/8" 0.354 $168
1/2" 0.472 $214

Plex-G 4x8 sheet Opaque Black
1/4" 0.236 $130

Those are the best prices I could find. So I loaded up with some material for a few projects I have in the works, next step is to get the router. The woodworking store in my town has a great deal on a Bosch router set that I'm going to get, then a Bosch router table to get me by until I make my own, and I'll have get a set of Whiteside bits.

That's all for now. That you to all of you that contribute to this thread!!!

 

[ClemQuat]

I hate to do this but I'm going to ask questions that you've probably heard hundreds of times. I don't have the patience to search through these threads (including the archived one) to get the info I need.

We are working on building an acrylic box for an algae scrubber therefore it needs to be water tight but won't have much pressure from water (theoretically). We bought black acrylic which appears to be extruded due to the instructions to not use windex on it. The paper on it says Marga Cipta and a quick google search says it's cell cast?? Little confusing... Dimensions are 20" x 9.75" x 13" and we have 1/4" thick acrylic.

First, I'm trying to figure out this needle/wire method. At what point do you put the wires in? Do you place them and then place the acrylic on top of it? Then after 15-30 seconds after using the solvent you remove the wires?
Second, we purchased DAP Household Adhesive Sealant, 100% Silicone as our material to put the box together. After more reading, I'm thinking we should have gotten a solvent. We were more focused on something that said "aquarium safe". If we can get away with using this sealant, it would be great so it's one less thing to buy. Your thoughts?
Third, what are suggestions for things to clamp to? Are there any household items that might work? We currently don't have a gluing jig figured out...
Fourth (if we have to go with solvent), are you applying the solvent to the outside of the joint?

Hopefully I was clear and sorry for so many (likely repeat) questions. This is also making me realize we didn't plan or research as much as we should have when we decided to go this route.

Thanks,
Jenn

 

[Acrylics]

We are working on building an acrylic box for an algae scrubber therefore it needs to be water tight but won't have much pressure from water (theoretically). We bought black acrylic which appears to be extruded due to the instructions to not use windex on it. The paper on it says Marga Cipta and a quick google search says it's cell cast?? Little confusing... Dimensions are 20" x 9.75" x 13" and we have 1/4" thick acrylic.

instructions for acrylic are pretty much all the same. To the best of my knowledge, Marga Cipta is cell cast, but it's generally bad cell cast for these applications. Would much rather see you use extruded in this case.

First, I'm trying to figure out this needle/wire method. At what point do you put the wires in? Do you place them and then place the acrylic on top of it? Then after 15-30 seconds after using the solvent you remove the wires?
Second, we purchased DAP Household Adhesive Sealant, 100% Silicone as our material to put the box together. After more reading, I'm thinking we should have gotten a solvent. We were more focused on something that said "aquarium safe". If we can get away with using this sealant, it would be great so it's one less thing to buy. Your thoughts?
Third, what are suggestions for things to clamp to? Are there any household items that might work? We currently don't have a gluing jig figured out...
Fourth (if we have to go with solvent), are you applying the solvent to the outside of the joint?

First, forget the silicone, it's pretty much useless for what adhering acrylic together in a water-tight application.
For reference, take a look at the first page of the following thread for a brief tutorial; I believe it answers most of your questions if not all of them
http://www.reefcentral.com/forums/showthread.php?t=390652

HTH,
James

 

[ClemQuat]

instructions for acrylic are pretty much all the same. To the best of my knowledge, Marga Cipta is cell cast, but it's generally bad cell cast for these applications. Would much rather see you use extruded in this case.

First, forget the silicone, it's pretty much useless for what adhering acrylic together in a water-tight application.
For reference, take a look at the first page of the following thread for a brief tutorial; I believe it answers most of your questions if not all of them
http://www.reefcentral.com/forums/showthread.php?t=390652

HTH,
James

That thread is why I asked most of my questions. Guess I didn't read far enough into it.. Sorry about that.

 

[Floyd R Turbo]

ClemQuat,

I've built a few algae scrubber boxes and up to this point I've made them out of a mix of Plex-G black (cell cast) and Plex-MC clear, and I have made them by cutting the pieces to the 'final dimensions' and then using Weld-On #3. I was able to make the joints watertight and 'good enough' but over time, bubbles start to show in the joints and warping causes the joints to start to pull apart. Following the advice in this thread (and the DIY ATS thread that srusso and I manage) will put you on the right track. That mainly being:

For an ATS, you can get away with using a good extruded material, like Acrylite FF (and James, is Plexiglas MC ok also?) and use a minimum of 1/4" material no matter what. Otherwise solvent welding the joints is difficult. Also you definitely need to take bowing into account, not due to water pressure, but rather due to water absorbtion and heat from light. External bracing in an ATS is a must, even if you use thicker material.

Also it would be advisable to join the pieces in the manner described in this thread, by making the 'outside' piece 1/4" larger so that the joint fills in completely and you get a 'fillet' on either side of the perpendicular joint, and then flush trim the excess off 24 hrs after welding. Otherwise as the solvent bonding process continues, you will get bubbles and that may eventually lead to a leak/joint separation. Not what you want when having a water-filled box and a light right next to each other.

If you're bonding black to black, this is tricky, as you cannot see inside the joint to make sure it is sealed. This is where Weld On 40 or 42 comes into play, you can use either of those on the inside joint after the solvent weld is done as an insurance policy. Again, for our application (ATS) this is a situation that *most* people don't worry about, but we have to. Designing the box so that the black-to-black bond is avoided would help. But that means sacrificing some of the desired light blocking.

When you see my next ATS box build (actually, the next 4 I will be building) you will see that I address all of these issues. To do it right, you really need the right equipment, or at least access to it. For making just one device, you can probably get away with a few shortcuts.

 

[gods child]

sir turbo did you get any price on 1 inch? That is what I need to go with thank you for your reply sir

 

[Floyd R Turbo]

The only prices I got for 1" material were Acrylite GP for $539 and Plex-G for $590. I didn't bother asking about the Polycast at Sabic but that is probably what I would use since it's imperical (1"=1") instead of metric, which is probalby thinner, but like I said, I didn't look much into that thickness.

Where are you located?

http://www.sabicpolymershapes.com/polyshapes/en/Home/Home/home.html

Click locations and call them up. Also look up Laird

http://www.lairdplastics.com/

 

[gods child]

I live on Long Island Got a friend that works with this stuff all day .Said he would love to give me a hand building a tank .I said it would be the other way around I woulb helping him .That a lot more than he had said he can get it from the same place that thay get it at work .But he said at around 325 a sheet thats a big diff

 

[Floyd R Turbo]

What material is he talking about specifically though, is it Polycast, Acrylite GP, Plexiglas-G, or some other brand? Is is cell cast, continuous cast, or extruded? Is it domestic or imported? This is what you need to know before going any further.

 

[ClemQuat]

So I read the entire thread that you posted, James. One question I have wasn't answered (or brought up). We need to drill two holes. Do we do this before we glue the box together or can it be done after? Right now we can do it before.

I've got a list of supplies we need now. Weld-On 3 or 4 and 40 or 42, denatured alcohol, and a syringe/applicator bottle. We're headed to HD/Lowe's to see if they have any or all of these. I'm crossing my fingers but using the search function on HD yielded zip for "Weld On".

Turbo: I'd be lying if I said you don't have me worried. I'm an engineer so this build has been trying for me with not doing a lot of research on my part. My BF James has been doing all the reading until today. We had all the pieces pre cut from the place we ordered from. We're not in a position to return any of it and get the materials that have been suggested. Therefore we don't really have much room for what you mentioned:

Also it would be advisable to join the pieces in the manner described in this thread, by making the 'outside' piece 1/4" larger so that the joint fills in completely and you get a 'fillet' on either side of the perpendicular joint, and then flush trim the excess off 24 hrs after welding.

I'm actually a little confused as to what that means anyway. I'll ask some of my ATS questions in the proper thread and post some pictures of what we have so far. Thanks for the advice!

 

[Floyd R Turbo]

Most full tanks or sumps are assembled by taking the front or back and laying it flat, then setting the end (side) on top of it and positioning it where it will be bonded so that the front overlaps the end. The finished product has this corner such that the outside edge of the front piece is flush with the side, but that's not the way it's bonded. The front is usually cut to be 1/4" longer than the intended finished dimension, then the end panel is positioned such that there is a 1/8" lip that sticks out that will be trimmed off after the bond is formed. This is done because as you feed the solvent into the gap formed by the pins, then pull the pins and push in the shims, the glue will form a fillet

http://en.wikipedia.org/wiki/Fillet_(mechanics)

on either side of the joint, which helps prevent air from being sucked into the joint as the MC evaporates.

For an ATS box, it may not be that big of a deal. The only instance during which the box will fill up completely is when the drain clogs (which shouldn't happen if you maintain is properly) or when the screen grows thick, depending on where you place the drain. You can always run a bead of WO 40/42.

FYI you won't find any weld-on at your local hardware store. The only place I could find it was at my acrylic supply place. In CT you can probably get it somewhere within reasonable driving distance.

#40 is a 2-part mix kind of like epoxy (but it's not) and you can use that to run a bead after the initial joint with 3 or 4 is done. I don't know for sure how long you want to wait between the two, the longer the better I would think so that the weld has time to 'relax'. #42 is the same as #40 except it's in a tube and you need a gun and applicator tips, so unless you use a lot of it, just get the #40. I got mine online at ridout plastics www.eplastics.com.

 

[Acrylics]

So I read the entire thread that you posted, James. One question I have wasn't answered (or brought up). We need to drill two holes. Do we do this before we glue the box together or can it be done after? Right now we can do it before.

Doesn't matter, holes are holes, drill before or after - up to you. I drill the before gluing cuz I hate cleaning shavings out of finished products and the more crud flying around raw material is more chance for things to go south.

I've got a list of supplies we need now. Weld-On 3 or 4 and 40 or 42, denatured alcohol, and a syringe/applicator bottle. We're headed to HD/Lowe's to see if they have any or all of these. I'm crossing my fingers but using the search function on HD yielded zip for "Weld On".

They'll have the denatured alcohol in the paint section, also called shellac thinner. I've never seen any hardware store carry solvent or solvent applicators. Plastic supply shops are the places to get these items.

@Floyd, for the most part, extruded is extruded, Plex MC is fine. I prefer Acrylite FF only because the surface quality is the best IMO.

James

 

[Floyd R Turbo]

Awesome. Local guy carries clear FF, more $ than Sabic, but I don't have to drive 4 hrs each way.

Right now I am all focused on router bits. I have settled on the Bosch 1617EVSPK kit and the Bosch router table for a start. Eventually will build my own table, but this one will do for now. Right now I have a Ryobi combo table/router that I haven't even opened, because the fence is a total joke. But for my current needs, I can get a stock table, and the Bosch one is about the best one I've found (for a stock table). I can hook my shop-vac up to it and rig up my air compressor to keep the bit free of chips. Plus Lowe's (and Home Depot) has a pretty liberal return policy.

All the notes I've taken have basically led me to the conclusion that the best bits are Whiteside, but other good ones are Bosch, Amana, Onsrud. I know that the big box HWSs have Bosch, and I have a few bits, but they're 1/4" shank so I will have to go up to the 1/2". My local woodoworking store has Amana, Timberline, and Freud, the Amana and Freud look good, Timberline not so much. You know which one is better when one brand is in a locked case and the other is not.

For trimming off flashings, I will be getting a spiral upcut flush trim bit to keep chips away from the bearing. I think I will end up buying whatever I can find that works, as long as the brand is a decent one, then I will invest in the Whiteside bits when I have a better feel.

For squaring edges, I will get a double-fluted bit of the highest diameter I can reasonable afford. I read that the 1.5" bits cut like a dream, so we'll see what I can find.

I will also pick up a 1/8" roundover bit for outside corners.

One question, I had always kind of assumed that Onsrud bits were the best for acrylic. But it seems like just about any good bit will do. Is there any specific advantage to the Onsrud bits?

 

[Acrylics]

One question, I had always kind of assumed that Onsrud bits were the best for acrylic. But it seems like just about any good bit will do. Is there any specific advantage to the Onsrud bits?

Onsrud cutters are good, but IMO/IME the are designed for production CNC machining and stacking sheets where specific feed rates and whatnot are assumed, not necessarily one-off or hand machining. I wouldn't argue with you if you decide to go that route, but IME, nothing specifically tailored to acrylic is significantly better than those cutter/blades used for other applications - provided rake angles and other geometries are similar.

James

 

[sean04]

Hi,

I want to build an external overflow on my acrylic tank. I have a basic 55 gallon acrylic with a blue back. How do I know that the material this tank was made of is one of the recommended types? If I spend the extra money buying the material for an external overflow and my tank itself is made up of the cheap acrylic, wouldn't that cause problems?

Thanks!

 

[Acrylics]

Hi,

I want to build an external overflow on my acrylic tank. I have a basic 55 gallon acrylic with a blue back. How do I know that the material this tank was made of is one of the recommended types? If I spend the extra money buying the material for an external overflow and my tank itself is made up of the cheap acrylic, wouldn't that cause problems?

Thanks!

All of the cheaper tanks that I've see are using good material. They make them cheap cuz they're using thin material and lots of 'em. The bigger question in my mind is; considering the tank is made without about as thin of a material as you can get away with - how much structural integrity are you losing in cutting out the back of the tank? Not saying don't do it, but just be *real* careful.

James

 

[sean04]

Thanks for the advise.

My idea was to have a thin internal overflow and have a few holes on the back that would dump the water out to the external overflow. Then my external overflow will have the bulkheads with pipes feeding back down to the sump below.

Does anyone have any shops I can buy the good acrylic in the SF Bay area that sells small quantities?

 

[CJBROWN]

Thanks for the advise.

My idea was to have a thin internal overflow and have a few holes on the back that would dump the water out to the external overflow. Then my external overflow will have the bulkheads with pipes feeding back down to the sump below.

Does anyone have any shops I can buy the good acrylic in the SF Bay area that sells small quantities?

A plastics manufacturer should be able to supply scraps by the pound. We have one here in Costa Mesa, great place to pick up project pieces. At 20lbs the price is $1.30 a pound. I got enough to make a ATO reservoir and a mini cocktail table to hang on the side of my tank base.

Did a quick search for acrylic manufacturers in SF, these guys came up in Petaluma: http://www.archplastics.com/

 

[Phishguy]

are there multiple types of cell cast acrylic and is one better than the other? I am having to build my mantis tank after all and I found this cell cast acrylic locally at a plastics company. can someone (james) please take a look and let me know that it's ok? It doesnt list any of the brand names that are mentioned. Thanks

http://www.lairdplastics.com/content/view/886/71/