Need help reducing PVA stringing on Qidi Tech 1

[Roguenorm]

Hey all,
I'm trying to get my dual extruder Qidi Tech 1 (essentially a FlashForge Creator Pro clone) working with PVA so I can start using it for dissolvable supports. I've managed to get most of the settings dialed in, any my benchy prints pretty well (see attached) with good detail and good bed adherence. (Not that I stopped the print after bridging of the front window)

However, there is way too much stringing. I've been using the 10 minute calibration test (https://www.thingiverse.com/thing:1815784) to play with retraction and temperature, with no luck. No matter what I've tried, stringing remains about the same, as you can see from the five different tests I printed.

Here are the settings I've been adjusting and the ranges:
extruder temperature: 180 to 195 in 5d increments
retraction: 1 mm to 7 mm
retraction speed: 20 mm, 25 mm, 60 mm
Coasting: off and on with value of 0.2 mm
zlift: off and on with a value of 0.4 mm

[EDIT] I am printing at 0.1 mm resolution

Frankly, I'm at a loss, I would have thought at least one of these parameters would have changed things, but stringing seems to be virtually identical no matter what I did. (note, some prints I cancelled part way through because it was obvious stringing was the same. That's why some of the column heights are different)

Any suggestions on what I can try next?
Norm

[rrdavis]

PVA is a very tough material to print with. There's some good starting suggestions at the link below:
https://www.simplify3d.com/support/materials-guide/pva/

Is this a brand new roll of filament? If not, they really do become useless after being exposed to the air for too long. They start to string and blob like crazy.

[airscapes]

Had trouble with PLA stringing after a few days of use. Got one of these https://www.amazon.com/Presto-Dehydro-D ... B008H2OEKK
Cut out the screen on 2 of the trays to accept the roll and ran it at 140F over night.. no more strings..
Good luck

[Roguenorm]

hmmm.... I had hoped moisture was not my problem with the stringing. I did have problems with this spool of filament clogging the extruder in the past. I dried it in the oven for about 5 hours and it has been in a sealed 21 cup rubbermaid container with dessicant ever since. Supposedly moisture content is still only about 15% based on the little indicators on the dessicant packages. I had hoped that was sufficient and certainly the benchy print was great apart from the stringing.

I do have another spool of the PVA I can open up and try. Just didn't want to do that unless I absolutely had to. May be the only option.

One other thing to note is that I am finding that my PLA is also stringing quite a bit using the same pillar test. Not as bad as the PVA mind, but still more than expected given the almost no stringing on my bency print with the PLA. I'm just wondering if excessive oozing is simply a problem with the Qidi Tech design?