Reef Safe Plastics

[Cory]

Ok well i guess activated carbon would remove that compound? Lots lf people have used it but the only concern was it breaking down by uv light. Then they made the pomd version which doesnt.

Msds for pond foam seems the same?

http://www.dow.com/webapps/msds/ShowPDF.aspx?id=090003e8803b2d8f

 

[Prozium]

Do you recall where you saw that?

FWIW, I don't see how lye solution will have that effect (although I've never tried it), or that water would penetrate this very hydrophobic plastic anyway. I do see how wax would seal it, but I used an untreated ABS sump for many years with no issues that I ever detected.

It's not so much the material, as it is the 3D printing process. "As a result of the layer-by-layer deposition characteristics of Additive Manufacturing (AM) processes, fabricated parts exhibit limiting qualities and have yet to achieve the requirements for end-use applications. Specifically, the use of AM-fabricated parts in fluid pressure applications is limited due to part porosity as well as non-optimized building variables (e.g., build orientation and material properties)." (from the PDF I linked below)

Hmm I can't seem to find the information that said the lye would work. I thought I had read it and saved the article, but I can't seem to find it.

cope413 on here suggested I look into it, but as of today's search the only thing I found was a hint that some people use it to desolve PLA support material.

I did find this PDF document that tested some sealers on FDM parts: http://sffsymposium.engr.utexas.edu/Manuscripts/2011/2011-15-Mireles.pdf
"Minwax Sanding Sealer" or "Thompson's WaterSeal" be a good choice?

 

[Randy Holmes-Farley]

Oh, I didn't realize it was printed. Mine was a big molded part from Home Depot.

 

[FranklinDattein]

Great thread. following.

I have been doing a fair bit of 3D printing for my tank and controller in the past 3 years. Reefing for me has always been 60% about DIY and building things and the 3D printer is the ultimate tool. If you also enjoy DIY, I strongly recommend a 3D printer.

I print prototypes in PLA, as the ABS fumes are toxic and the printer is right under my nose. Once I am happy, I reprint it in ABS.
I have also experimented with Nylon, I just don't have any aplication for flexible plastic.

Just for curiosity I have placed a couple of small PLA parts in the sump, a mix of colorless and colored parts. They have been there for over 1 year and so far no noticeable signs of being consumed or losing color. So my pratical experiment has been positive, so far.

Tank is mixed reef, with LPS, SPS, clams and softies, using passive activate carbon, Vinegar dosing and Phosguard.

 

[TylerS]

Nylons mechanical properties and final part sizes are affected significantly by moisture when compared with other plastics. I would go with ABS.

 

[Randy Holmes-Farley]

Ok well i guess activated carbon would remove that compound? Lots lf people have used it but the only concern was it breaking down by uv light. Then they made the pomd version which doesnt.

Msds for pond foam seems the same?

http://www.dow.com/webapps/msds/ShowPDF.aspx?id=090003e8803b2d8f

Yes, GAC would remove it.

That MSDS certainly lists lots of stuff I wouldn't add as uncured chemicals.

 

[Prozium]

What about smoothing ABS with acetone, would it be OK after it has had time to evaporate/rinse?
I'd either apply it lightly with a rag, or like in this video.

 

[Randy Holmes-Farley]

Trace amounts of acetone are not a big deal.

 

[Prozium]

Trace amounts of acetone are not a big deal.

Thanks! I'll have to try it out then.

 

[Randy Holmes-Farley]

You're welcome.

Happy Reefing.

 

[Milktooth]

Hey it's not a 3D printer issue but I do have a materials safety question for you guys. See link to my question :
https://www.reef2reef.com/index.php?threads/286050/
Safety of these materials

 

[Randy Holmes-Farley]

deleted

 

[starvinmarvin01]

Hey! Great thread - I appreciate the information and it seems like the consensus is that for the purposes of printing "Frag plugs" or in-tank decorations, or stuff like Algae clips, breeder boxes, etc, a person could use PLA if they were ok with the product breaking down and dissolving into the tank over an extended period of time, and it seems like user experience on this thread indicates that a 1-3 year period is too short to notice any of that dissolution.

For items like overflow boxes, sump baffles, skimmer parts, or anything holding back water from getting your feet wet, it seems like ABS is a good choice provided you can smooth it out to ensure the correct adhesion between the Additive layers, or are ok with the end result your printer produces for the application at hand.

Did I capture/summarize/understand that correctly?

If so - I had 3 follow up questions:

(1) I was wondering if anyone knows whether PLA or ABS can be bonded well with cyanoacrylate glue? And would a person need to rough up the surface with sandpaper? What would the best grit be to use, if so?

(2) Which has more strength (ABS or PLA) in the application of making a "Frag rack" which will have magnets glued to it, and some weight placed on it? As far as having it not "crack" from the weight when stuck to the side of the glass and having Frag plugs placed on it.

(3) Would Smooth-On Smooth Cast 327 stick to ABS or PLA printed products? It's a tintable 2-part resin for giving the item some aesthetic colour. It's made from 35% 4,4' Methylene bis(phenylisocyanate) (MDI), and 55% Polymethylene polyphenyl isocyanates, and 10% Butyl benzyl phthalate. It is advertised as a reef-safe product for painting decorations.


Thanks in advance,
Marvin

 

[Randy Holmes-Farley]

I don't know much about biopellets, but could they be 3d printed in PLA? If so could they be designed to be super efficient in terms of the amount of bacteria they can serve?

Not sure what you mean. You just mean make a high surface area for growth?

 

[FranklinDattein]

@starvinmarvin01 that is a pretty good summary, but I would also consider the following:
- It isn't clear what side effects PLA could cause in the long term. It could, for example, leech the filament coloring ink or any other chemical that was mixed in it.
- The types of Filament types are growing fast and PLA and ABS are no longer the only options. I wouldn't be surprised if there is already a filament with the best of both worlds, that isn't toxic and also doesn't dissolve in saltwater.

(1) I was wondering if anyone knows whether PLA or ABS can be bonded well with cyanoacrylate glue? And would a person need to rough up the surface with sandpaper? What would the best grit be to use, if so?

There is plenty of youtube videos on how to glue both. The topic is extensive.

(2) Which has more strength (ABS or PLA) in the application of making a "Frag rack" which will have magnets glued to it, and some weight placed on it? As far as having it not "crack" from the weight when stuck to the side of the glass and having Frag plugs placed on it.

If you ignore the fact PLA will become brittle in saltwater, these points are more dependent on design and printing characteristics, than the material itself.
Things like thickness, infill percentage and a good design with no weak points, will make the difference here. For example, a frag rack with 50% infill will absorb water, while 100% wont - regardless of material.

One of the main advantages of 3D printing is that you have endless possibilities when it comes to designing object structure.

 

[cope413]

CA glue works great on PLA and ABS. Though for max strength, use a solvent weld for ABS. I think I used weld-on 77 and it works very well.

For strength, ABS will certainly hold up better than PLA.

I'm going on 3 years now with a PLA overflow on one tank, and an ABS on another. No issues with either and both have been removed once or twice for cleaning/maintenance.

I smoothed the ABS one with acetone too.

I printed some screens out of nylon for my wp-40s after a lawnmower blenny decided it would be smart to go into one while it was off for a few seconds.

I've printed parts in TPU, nylon, PETG, PLA, and ABS. They've all been in tanks for 2+ years. Not a single issue.

 

[starvinmarvin01]

I printed some screens out of nylon for my wp-40s after a lawnmower blenny decided it would be smart to go into one while it was off for a few seconds.

Cool! What Nylon filament did you use? And why did you choose Nylon for this application?

...a frag rack with 50% infill will absorb water, while 100% wont - regardless of material.

Good point!

 

[cope413]

I used MatterHackers pro series black nylon. I used it because it's black, and because nylon is the toughest material I've used in the tank. I clean my powerheads fairly frequently, and the nylon doesn't crack or break with repeated removal and reassembly

 

[Divreig]

Very confused on this subject. As per everything I've read Not Aquarium related ABS is not considered food safe because it gives off a toxins. But everybody seems to recommend abs on various fish forums. Also I've been told Legos are made out of abs, so they must be food safe if toddlers put them in their mouth all the time.

So how can ABS be fish safe but not food safe?

 

[cope413]

So how can ABS be fish safe but not food safe?

"Food Safe" does not mean what most people think it means. First, you ought to be instantly skeptical these days when you hear the word "toxins" - especially as it relates to food. (As an aside, you ought to ask anyone speaking about "toxins" to provide you with the specific chemical(s) they are referring to)

As for ABS, it's a polymer made up of Acrylontrile, Butadiene, and Styrene.

Each of these, by itself, is definitely not good for humans or aquatic life - acrylonitrile especially so.

Enter the magic of polymer chemistry.

ABS is a pretty stable polymer. Unless you're burning it, it doesn't really decompose into its monomers (acrylonitrile, butadiene, and styrene). Contrary to what you may have heard, it doesn't "leach".

I know I swallowed quite a few Legos in my younger years, and am happy to report no ill-effects

Now, regarding the "food safe" part. There is more to getting FDA approval for direct or indirect food contact than just the chemical formula of the plastic.

A significant portion of that designation has to do with the ability to clean/sanitize the object after use.

So, for example, I could take an FDA approved plastic like PET, put it in filament form, and print something with a 3D printer, and the printed object would not be FDA approved for food contact.

Why? Because the process of 3D printing inherently leaves a bunch of gaps and crevices on the surface of the part that would/could become breeding grounds for bacteria and other microbes.

So, you could have a perfectly safe plastic that doesn't leach any harmful chemicals, and poses no threat to humans, but have it in a non-food-safe form.

As for how you can be certain that ABS is reef-safe...

Many (most?) of the pumps and wavemakers are made of ABS. There are lots of common plumbing fittings (typically bulkheads) that are ABS. Media reactors, parts of protein skimmers, and other common reef devices are made of, or use ABS plastic.

Anecdotally, I have 3D printed at least a dozen ABS parts for 3 of my tanks, and they have been running for 3+ years with no issues.