Question PET G printing issues

I recently purchased a roll of PETG filament and have been having major problems trying to print with it. It seems to be stringy and huge globs appear in the print which end up meaning i have to stop the print, since the print head wont go over them.
I am printing it at 230c. its 1.75mm filament. 0.2mm nozzle.
I have tried slowing the feed rate but still get problems and I upped the hotend temp from 215c to 230c which didnt seem to help either.

Has anyone experienced this before and can recommend what I might be doing wrong?
Alternately - could it just be a bad batch of filament?

hopefully this illustrates problem. this was a test print so i can check sizes and shrinkage etc. With the big blob in the centre i didnt allow it to finish printing, but you can see the stringy natures, plus the blobs.

Hi
I print PET-G with a 0.4 nozzle at 250 degrees C.

wow, thanks. if mine came out like that i would be very happy.
I will try and emulate some of your settings and see how i go.

hi guys.
I also print PET-G with a 0.4mm nozzle at temps between 240 and 250 at 60mm/s depending on the filament that arrives as they vary a bit. Its a little hard to tell from a single photo but looks like the problems i was having before i upgraded to a j-head v6. The nozzle heats up initially before you start printing but as the filament passes through the nozzle it cools as it heats the plastic until the nozzle temp drops bellow the PET-G melting point and jams the nozzle. Once it is jammed and no more filament can pass the heater brings the nozzle temp up again as the filament is no longer moving and where the extruder was still trying to push filament through while jammed that pressure causes a blob with a string on it. Also the retract wont work while jammed no matter what the settings are. Nearly drove me mental i can tell you.
The things i would try are raising the nozzle temp to 250C and turn the print speed down to about 30mm/s until you get it printing and the bring the print speed up until problems start then back it off a bit.
If you are using a Bowden setup then this will increase the problem as there is loads of elasticity in the Bowden tube. I use a direct drive extruder with a mount that i printed myself from a thingiverse design that allows me to print PLA, PET-G, ABS, TPU as these are the ones ive tried. My next adventure is a hardened steel nozzle and carbon fibre.
You may have a completely different problem to the one above but it might help
Does your printer print PLA ok?

Thanks @yellofella I print PLA and ABS with no problems. One thing I found after watching it carefully for a long time, was the petg was oozing out from where the heater block joins the threaded throat. That was causing the blobs. I tightened the heater block to the throat while whole unit was at printing temp and it improved that part of the print.
I am going to run some ABS and try a couple of prints to make sure everything is working and the filament is the problem - not some other printer issue. Then I can try the larger nozzle.

Hi buddy @Damien602
Sounds like your on the right path to fixing it but i would add this to help you if problems persist....
The filament oozing out of the top of heater block is usually a sign that the hotend was not put together properly before printing. There can be no gap at all between the threaded throat and the nozzle inside the heat block or the filament will melt and run up the threads and produce the mess that you describe dripping off the heat block. I myself would change the threaded throat, nozzle and heat block for new ones as they probably wont come apart now that there is melted filament gluing all 3 parts together and you will probably snap the threaded throat when you try to remove it from the heat block now anyway.
The procedure for installing the nozzle/hotend is as follows
While cold screw new 0.4mm nozzle all the way into the heat block with fingers then slacken off a quarter of a turn.
Screw threaded throat all the way into the heat block so it is touching the nozzle (there can be NO GAP).
Heat hotend to its maximum with no filament loaded then tighten the nozzle the quarter turn that you backed off before with a spanner to create a good seal between the threaded throat and nozzle (referred to as hot tightening). You have to make sure that you hot tighten the nozzle at a temp above what the printing temp will be and please be carefull as it is extremely hot. Also be aware that the spanner you will be tightening the nozzle with is made of metal and will suck the heat out of the hotend while tightening so be fairly quick with the spanner then let it heat up again for a few seconds then check its tight. It may not need the full quarter turn but you get what i mean.
This will completely stop the problems you are having with the blobbing and get you printing buddy.

Fantastic, thanks for the help everyone. I replaced the heater block and throat and did the hot tightening thing. I have been able to print in ABS with no issues.
Now to test for PETG again.

Here are the latest prints after taking some of the steps advised by yellofella and xxpelle.
Much better quality than previously. These are in ABS not petG though.

The biggest issue I had with PETG was the distance between the nozzle and the bed. It needs to NOT smoosh the fist layer, almost prints in air. It took a lot of trial and error to get it perfect. Also a clean nozzle tip helps (outside as well), ensure the filament isn't curling out of the nozzle. Just have it print in air above the bed to test. Other than that I had problems with the speed/cool ratio. The print would cool and rise to the nozzle after about 30 layers. Ended up knocking the print off the bed. Sadly I can't remember how I fixed it. I'm convinced my printer is a lemon based on the time I've spent fixing it vs. printing. That's half the fun I guess.

I hear you re lemon printers and spending more time to fix than to print! I have the Anet and while it prints OK and is cheap I have spent heaps of time fixing and updating it.
Some (most??) problems, admittedly, were my fault. Toasting the main board, breaking the print head fan, snapping the throat thread, etc. Here's a handy tip, dont try soldering the hot bed connector with the power on. Just saying...
Jury is out whether the hotend main board mosfet death last week was my fault, but either way i had to fix it. Luckily i had a spare main board that no longer worked.
On the positive side the DIY build part of those models gives great knowledge into how they work so fixing becomes easier.

I bought a prebuilt anycubic i3 mega-s. Had problems ever since I upgraded to an E3D hotend (hot end works great, but something is off). So many variables change when you make 1 adjustment. I love tinkering with it,but sometimes it's nice to just have it work .

Sounds like you need to calibrate your settings; especially if you haven't done so already. Make sure temp, esteps, z height and flow are are calibrated. Keep in mind, PETG generally needs around 5-10c more than PLA. I use an all-metal hot end, sand print at 245c nozzle and 65c bed.

I just got a roll of PETG and have been having similar issues. Just seems like softer gooey stringy stuff. Have played with some retraction settings, but doesn't feel like it has done anything. Have read several places about having a slightly larger print gap, so that was going to be my next attempt if I can figure out a way to do it without actually physically adjusting the base height of my bed (like just changing an offset value). The last roll of filament I bought was Colorfabb nGen which was great stuff, though a bit pricy. It printed really nicely though, had good mechanical properties, and didn't absorb water, so I could actually use up a whole roll over the few years it took me to go through it. Wanted to get another one, but figured I'd try some PETG since I can get it local and I thought it was supposed to be better about moisture absorption as well. So far still trying to get clean prints, though what has been coming out is functional, just ugly. I need to try to clean the nozzle really well as I think the stickiness of the filament makes it worse when it comes to clinging to a dirty nozzle.

Well, I made some good progress on this. I ended up buying a new plated nozzle thinking that might help the stickiness problem, which it did to some degree (it's very easy to clean, just wipes off), but the real issue I think was my software. I have a PowerSpec 3DX (Flashforge Creator X clone), which uses the old Makerbot style code, so I had been using ReplicatorG to slice with. I figured I'd give some other programs a try and my first print with Cura was near perfect, so that seems to have been the main difference. I'm fairly sure it just had to do with print speed though. I believe RepG is a little more "does whatever you tell it" while Cura does a lot of "settings relative to other settings". For instance, with RepG the print speed you pick is the print speed you get for the whole print, whereas with Cura you can have different speeds for the initial layer, top and bottom layers, infill, walls, etc. I think I'm hitting the extrusion limit of my hotend at higher speeds as I was getting some clicking the other day and had to slow things down a bit.

You can download some temperature towers to print, and according to the results, determine the suitable temperature printing.

petg is a bit tricky compared to PLA or ABS. all petg filaments from different manufacturers have slightly different properties which will greatly affect the stringing and quality of your prints. Requires quite a bit of tuning for the filament up front, so once you got a good working profile save it and always buy the same brand to keep this consistent. You will need to tune for speed, retract speed & distance, and temperature. I've seen some PETG work well at 210*C whereas others would need to be heated up to 240*C to function properly. All of this needs to be found out as part of your tuning process for that material, best way is to download print something called a temperature tower and also a stringing test. Search on thingiverse and a lot of items will come up for you to test. Even the best tuned printer will still have a bit of stringing or runoff while printing PETG, unless you incorporate things like nozzle wiping, etc but those greatly increase print time. It's just nature of the beast and you will need to deal with it in post processing step. For wall speeds I'd recommend something in between 25-40 mm/s with overall print speed of 40-60. Travel speed should be 120 mm/s

edit: to specifically answer your OP: if you see stringing, you generally want to *lower* your print temp. Oozing means the filament is liquifying too much, and is a result of it being melted at a higher temperature.
edit#2: Use latest version of CURA. They have some decent default settings, and have great editing parameters capability when switching to advanced mode.
edit #3: updated to more accurate speed range after checking my print profiles.