Can old filament be rehabilitated?

Ever since I started printing back in January, I have been enjoying trying different filament types, colours and suppliers to see what effects I could get - the consequence of this is that I have ended up with quite a number of part used reels. Until a few weeks ago, I did not store any of these in sealed bags with desiccant, I just left them on a shelf on a cupboard in a centrally heated room - in 5 months I had not seen any deterioration imprint quality...but now I have. Suddenly, a number of these part reels are showing the same symptom on printing with them - delamination of all layers apart from the very bottom one...it's just as if I was printing at too low a temp. and I can peel the layers apart like an onion. I always print at 195/185 and 65/60 and I (sadly) have now got enough examples to be pretty clear that most of my old reels are showing it and none of my more recent purchases. I immediately bought ziplock bags and silica gel (25g bags) and have left them for a couple of weeks now, but no improvement Has anyone else seen this and is there a way to get them back to the way they were before? I am hoping to not be limited to just few months life on reels, or to have to start guessing what print temp is likely to work on what age of reel...

I keep my reels in sealed bags, but unfortunately do not always remove and bag the reel that I was last printing with, and I tend to get the same issue near the end of some reels.

I suspect that your reels have absorbed a lot of water and so will need time and a lot of desiccant. They probably need to be in a sealed bag with a large quantity of desiccant in a warm place (airing cupboard perhaps), with the desiccant replaced or rejuvenated frequently for a couple of weeks. I believe silica gel can be rejuvenated in a microwave - Google should give details. Or bury the reel in lots of rice, maybe. If you can arrange to put the reels (not in bags) in a warm closed cupboard (e.g. a wardrobe) along with a dehumidifier for a week or two that should also work and need no desiccant, though empty the dehumidifier's water tray frequently until the cupboard gets sufficiently dry that water no longer collects.

If you print in ABS, consider rubbing down or dipping your prints in acetone. I have found that the acetone seeps into the layers and fuses them together, making the print significantly stronger and less prone to delamination. Until the acetone evaporates the print can get quite soft, so handle with care.

Dave
(#106)

Thanks Dave - reassuring to know I'm not the only one ...I'll keep the treatment going then and see how it goes over the next few weeks...I hadn't appreciated it could take that long...