Best way to completely dissolve PETG from nozzles?
Supposedly Acetone won't dissolve PETG, but MEK and/or Toluene will. The only problem is that MEK and Toluene are typically no longer stocked at the hardware store like they used to be. So, what to do? I notice that some of the cheaper lacquer thinners appear to contain those two solvents, such as: https://www.grainger.com/ec/pdf/5KPY2_1.pdf
Anyone using or aware of better PETG solvents for completely cleaning PETG from nozzles?
Best Answer by dimprov:
Ultrasonic cleaning at 40khz knocked off most of the residual:
There still exists some PETG inside the nozzle (I lack the equipment to photograph there), but the outside is clean enough. I think the lesson here for the future might be to use a cleaning filament to clean the inside of the nozzle *before* demounting it, so that the effectiveness of said cleaning could be evaluated by direct inspection after de-mounting.
As it stands, though, it could be re-mounted, and then cleaned after-the-fact with a cleaning filament as described by bobstro above:
I find it a lot easier to push some cleaning filament at 265C to melt any leftover PETG, let it cool then do a cold pull or three. Takes a few minutes of effort plus cool-down time, but it works well.
Then, as long as it prints well, one could infer that the cleaning worked.
By the way, this is a genuine E3D nozzle.
RE: Best way to completely dissolve PETG from nozzles?
They are absolutely stocked, In most states in the US, and hell I live IN California the worst state of them all. you can get Toluene all day long in the form of Goof off original, and methyl ethyl ketone is still on the shelf's everywhere. Most lacquers in the US are now water based (they have been fazing them out for the last ten years) now unless you have a lic. to get them (which I do) as well as a special HAZMAT training, the thinners aren't the same as they used to be. So buy Goof off , and Methyl Ethyl Ketone, shouldn't be an issue. (Ace Hardware). and you really don't need either to clean your nozzle, heat and/or a brass brush will do the trick on the outside no problem. inside can be handled a variety of ways.
The Filament Whisperer
RE: Best way to completely dissolve PETG from nozzles?
inside can be handled a variety of ways.
Which of those ways is the best?
RE: Best way to completely dissolve PETG from nozzles?
I have never let a nozzle get into that condition, regular cleaning inside and brass brush outside with a wipe with IPA (outside while hot) keeps them in very reasonable clean working order until its time to get rid of it from wear. that image shows neglect.
The Filament Whisperer
RE: Best way to completely dissolve PETG from nozzles?
I have never let a nozzle get into that condition, regular cleaning inside and brass brush outside with a wipe with IPA (outside while hot) keeps them in very reasonable clean working order until its time to get rid of it from wear. that image shows neglect.
It was brand new two weeks ago.... And it's a genuine E3D nozzle.
But a blob of death was involved, so maybe that's where it went south.
I'm a bit unsure about the brass wire brush because, well: Brash against brass? Seems like that might tear at the nozzle opening. Plus, I'll soon be switching to Matchless nozzles, and I don't want to wear away at their coatings.
RE: Best way to completely dissolve PETG from nozzles?
A small bottle of lacquer thinner costs on average $10 US. a new brass nozzle E3D average 10$ US, ( and that's only since COVID) a brass brush will not wear the outside of the nozzle out or effect the tip in a negative way, this has been proven over many years and isn't new. it is in fact the accepted method. (lacquer thinner is hit or miss and you will have to use it with caution as it is volatile) Matchless nozzles make for even easier cleaning, but since your going to buy them I'm sure you are already aware of this. however, if you don't take the time to care for them, they can look the same as the image you shown.
The Filament Whisperer
RE: Best way to completely dissolve PETG from nozzles?
@swiss_cheese
Thanks to your informative comments I have the neglected part now taking a bath in "Pro Strength" Goof-off at this very moment.
BTW, what's your favorite brand of lacquer thinner? I've tried the Sunnyvale brand that I linked to above but found it incredibly noxious. I'm partial to the Jasco myself (the original, definitely not the "green" version), which Lowes still sells. When I last looked into it, I was surprised to learn the term "lacquer thinner" isn't particularly well defined, and so different manufacturers can have very different formulations.
RE: Best way to completely dissolve PETG from nozzles?
Hmmm... Well, after 5-10 minutes of soaking in the "Pro Strength" Goof-off, I'm not seeing any dissolving at all. Not even a hint of it.
I had no idea PETG was so chemical resistant. I may have to step it up to paint stripper. That stuff is liquid death.
RE: Best way to completely dissolve PETG from nozzles?
Ah, this explains it: https://goofoffproducts.com/wp-content/uploads/2017/08/ProStrengthAerosolRemoverMSDS.pdf
There's no toluene in it, nor any MEK.
I guess I'll try the Sunnyvale lacquer thinner next.
RE: Best way to completely dissolve PETG from nozzles?
Well, the sunnyside lacquer thinner was another fail. God only knows what's really in that stuff.
So, I stepped it up to Jasco Paint and Epoxy Remover, which it's now bathing in and which is the strongest stuff I have on hand.
RE: Best way to completely dissolve PETG from nozzles?
Your right, Goof off was "Xylene" not Toluene, and apparently now its only Acetone. you can still buy MEK at, Home Depot, Lowes, Walmart
The Filament Whisperer
RE: Best way to completely dissolve PETG from nozzles?
Reporting back: after sitting for 25 minutes in paint stripper, chunks of the PETG have broken off into the solution, but I'd say even more is still attached. Honestly, I was expecting much faster results than this. I'll let it soak overnight.
It has me wondering now as to whether even pure MEK and/or Toluene would also be slow acting as well.
RE: Best way to completely dissolve PETG from nozzles?
It certainly would be nice If I could refresh a thread without having to leave the page and come back. the refresh page option doesn't seem to work here.
The Filament Whisperer
RE: Best way to completely dissolve PETG from nozzles?
It certainly would be nice If I could refresh a thread without having to leave the page and come back. the refresh page option doesn't seem to work here.
It might be your browser cache. You could turn off caching, and then maybe it would work the way you want.
RE: Best way to completely dissolve PETG from nozzles?
I find it a lot easier to push some cleaning filament at 265C to melt any leftover PETG, let it cool then do a cold pull or three. Takes a few minutes of effort plus cool-down time, but it works well.
RE: Best way to completely dissolve PETG from nozzles?
@bobstro
Good suggestion!
As a last resort someone on the stackexchange chemistry forum claims "very good experience" in using Tetrahydrofuran to dissolve both freshly printed PETG as well as any overheated residues: https://chemistry.stackexchange.com/questions/61703/solvents-adequate-for-dissolving-overheated-polyethylene-terephthalate-glycol-mo
Unfortunately, he makes no mention of how long it takes, which, based on tonight's trials, seems like it may be an important consideration.
Amazon actually sells the stuff: 
RE: Best way to completely dissolve PETG from nozzles?
[...] As a last resort someone on the stackexchange chemistry forum claims "very good experience" in using Tetrahydrofuran to dissolve both freshly printed PETG as well as any overheated residues [...] Amazon actually sells the stuff.
Interesting reading the Amazon page. THF can apparently be used for smoothing PLA prints. While it may not be useful for clearing your nozzles of PETG, a quick experiment with PLA would be most interesting! Let us know if you try it.
RE: Best way to completely dissolve PETG from nozzles?
@dimprov
Was a sock fitted when the printer did that to the nozzle? If not, always wear protection!
RE: Best way to completely dissolve PETG from nozzles?
@dimprov
Was a sock fitted when the printer did that to the nozzle? If not, always wear protection!
Yes, indeed. It was even an official E3D sock.
RE: Best way to completely dissolve PETG from nozzles?
Just noting that THF is not a particularly pleasant substance to be using without suitable safety precautions - similar to DCM - ventilation and suitable PPE required.