Sanitizing 3D printed parts

[bjhbrew]

I'm guessing that with all the DIYers on this board that there are people printing parts to use in their home breweries. I have access to a machine that prints using pla but I'm completly new to the concept. One thing that I've noticed is that while the parts come off with great accuracy and detail that the surface is kind of rough. So what do y'all think could I sanitize a finished part in a starsan dunk or am I just looking for trouble? If it makes a difference, the part I'd like to make is a bulkhead fitting that would attach to the lid of my fermonster so it may or may not contact the fermenting wort.

 

[corey1581]

I don't know much about the material used in the 3D printing process, but a Star San dunk should do just fine I think, as far as sanitizing it.

 

[brewslinger]

From what I have heard regarding most 3d printer raw material is that it is not food safe.
I would recommend against beer contact at this time.

 

[brewslinger]

FYI: An acetone mist apparently can partially dissolve the surface making it smoother.
http://makezine.com/2014/09/24/smoothing-out-your-3d-prints-with-acetone-vapor/

 

[bjhbrew]

Hmmm, thanks for the replies. I'll look into the food safe angle, my understanding was that the pla was food safe while the abs is not. I like the acetone idea I'll look more into that too

 

[mattd2]

There doesn't seem to be a lot of info on chemical resistance of PLA, I would not hold my breath but the best bet would be to print out a test piece (or just get some of the PLA filament from the spool) and test it in some stars an to see if it gets brittle or starts to disintegrate.

 

[Golyo]

PLA is corn starch, it is mostly food safe, and there is special food safe PLA that could be used, if it is in constant contact with the wort or beer. There is also PETG that is also considered food safe.

 

[brewslinger]

That's good to hear!

 

[kaminsknator]

PLA will continue to absorb moisture over time and become brittle. I would recommend PETG. It is really easy to print with only requiring a higher temperature. PETG is food safe as well. PETG has the benefite of being temperature resistant and stronger than PLA also.

 

[bjhbrew]

Great info, thanks all for offering your insights. I think I'll give it a shot with pla first as I have a friend who uses it exclusively on her machine. If I find that sanitizing it with starsan causes it to break down than I'll look into getting my hands on some pets filament. The part that I'm hoping to make would be a bulkhead with probably 1/2" npt thread that would seal through a fermonster lid and the have the same threads as a pop bottle on the outside so I can cap it with a pop lid during primary ferment (with airlock) and the take the lid off and screw on a carbonater cap to push the beer out under co2. That's the thought anyway...

 

[tomofdarkness]

If you're going to be in contact with foodstuffs, you should coat it in a food safe epoxy. Worth noting is that PLA softens considerably at around 130-160F and so you should be careful not to expose it to hot wort....

And now I see that this is from 3 months ago, so now I'm curious what you ended up doing

 

[bjhbrew]

Haha, I kinda stalled out on this one. I'd still like to try out this project so I'll report back if I make it past the modelling stage. (Learning solid works is hard)

 

[Sadu]

PLA is foodsafe but the pigments they use to color it aren't always foodsafe. So buy one that actually says foodsafe.
The other risk is the tiny gaps in between layers makes it real hard to sanitise.

 

[barrooze]

I'm looking to print something similar to MoreBeer's Ultimate Sparge Arm, so it'll need to handle hot wort. I've read PETG is foodsafe and can handle higher temps. Do you guys think this will be a good filament to use? Should I still coat in a foodsafe epoxy? Suggestions for this epoxy?

 

[tomofdarkness]

better safe than sorry, I say. PETG is a pain to print in, make sure you have an enclosed build chamber. I'd still coat it in a food safe epoxy to eliminate the rough spots that could harbor bacteria between sessions, but that's your call ultimately.

 

[sandyeggoxj]

This is going in the mash so it doesn't need to be sanitized. Just cleaned after use.

But stick with food safe filaments. PLA gets soft at warm temps and will just flop around.

 

[boasist]

I printed up a few misc. sized bowls for myself in PETG. Prusa mk2, really tight layer size, it isn't watertight, but with your application, it shouldn't matter.

Either way, I've never had any issue with them being exposed to the boil or mash.

 

[barrooze]

Thanks all for the input! I just ordered my printer, so I'll let you know how this project goes for me! Thanks again!

 

[sandyeggoxj]

What printer did you order??

 

[barrooze]

I went with the Monoprice Maker Select V2. Seemed like a good printer with a decent print size. I’ll be doing the MOSFET mods to it. I’m getting a couple spools of PLA and a bud from work gave me half a spool of PETG to mess with.