Printing Issue (filament caused?)

Hello all, first time posting here. I have been working around 3D printing for just over a year on a weekly, hands-on basis for research at school and personal use/learning. I have a roll of PLA filament that I've had opened (and not stored with silica or in zip-lock-bag) for about 5 months and am getting to the bottom 3rd of it now. I'm well aware that PLA absorbs water and will degrade over time without proper storage, so I'm sure my problems are due to this filament. As you can see with the two pictures I posted, these are my most recent attempts to print with my cr 10. 

 

The finished print has a corroded look to me. This print was set at 100% infill, and while the walls are thin at in the upper section I do not think it looks right. This is where I suspect the filament is the issues, based on the look and weakness of my print even at 100%.

 

The clumps on the bed are when I went back to use try older files that I had perfect success with. The extruder would follow the correct paths, but spurt clumps of PLA onto the bed and vibrate greatly at the extruder motor.

 

If anyone can confirm this is most likely a filament issue that would be great! I have a fresh, unopened roll that I can use tonight but wanted to wait and see if there were other possible problems that could cause this (jams, extruder head degradation, etc.). Thanks!

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From your description, I'd say you're right. High moisture can cause everything you're experiencing and worse. The melting point of the filament is nearly double the boiling point of water. Even a small amount of water can vaporize quite violently. Steam has a volume 1,600 times that of water at normal atmospheric pressure. So even a little moisture can have a dramatic effect when suddenly heated to twice its boiling point. Rather than trying to desiccate the filament on the heated bed, I'd recommend putting it in an oven at 100° - 120° F for about 90 minutes to two hours. It takes a little time to get the moisture out this way but it's about the only way to evenly heat the whole spool. Heating on the bed will tend to overheat part of the filament and leave moisture in the rest. Also take care not to let it get too hot as it can become brittle and unusable. 100° - 125° in a dry oven is plenty hot enough to evaporate any moisture. If it still acts up put it back in a bit longer, just enough time and temp to get the job done. In the future put the spool in a big zip-lock bag with a desiccant pouch when not printing for more than a day or so. PLA is especially sensitive to absorbing moisture.

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While it's possible that your material is wet (heat your bed up to about 50 degrees and leave the material on it for an hour or 2 to fix), the uniform nature of the blobs look like you're over extruding too hot or your print head is a bit too low and you're seeing a pressure buildup that's forcing the material out as a blob...

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That sounds like your filament has picked up some moisture, maybe making parts of it swell.

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