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I'm curious what you guys use for dry boxes or methods to dry out your filament. The oven seems cumbersome, and dessicants don't really seem to get the job done for me. Do you guys use an active or really good passive dehydration strategies for your filament? pics encouraged

I have a large tight fitting lid box with a goldenrod gunsafe dryer in it, works great. even the nylon is dry!

Hey Kevin, what kind of container do you use? the goldenrod seems like a great strategy

I found a Sterilite branded storage tub at Target with a gasket in the lid. It does vent air if you press on the lid, so it's no pressure chamber, but if you throw a book or something on top of it, it puts pressure on the gasket and definitely stops air exchange. I bought a box of desiccant from Amazon and a tub of damp rid from Lowes, and that's where I've been keeping my filament.

The real trick is just to print enough that it's gone before it takes on moisture

If you've got a lot of filament, set aside a closing cupboard and place the filament on shelves with a 100w incandescent lamp on the lowest shelf (filament should be on that shelf or above) the heat generated by the lamp will warm the shelves and surrounding air keeping it all nice and dry Not as fast as oven methods etc but it's a great long term storage solution. Bonus points if you seal the cupboard to slow airflow. Points taken away if you cause it to get too hot and set fire to your home.

jeffhuber wrote:Hey Kevin, what kind of container do you use? the goldenrod seems like a great strategy

Just a big plastic tub from lowes with weight on top to seal it

I keep mine in individually wrapped bags with a desiccant packet in them.
I have yet to have any popping or surface quality issues.

I print with Botfeeder ABS that is almost a year old.

Well I ended up buying this dehumidifier rod - http://www.amazon.com/gp/product/B004QU ... UTF8&psc=1

I also bought a hydrometer. Does anyone know what the "ideal" humidity is? Or the less, the better?

taulman bridge has been soaking up moisture like crazy!

This is interesting. Using a desiccant removes moisture from the air and leaves the temperature constant; the result is that the relative humidity drops. Using a heater increases the temperature and leaves the amount of moisture constant; the result is that the relative humidity drops. Are the two methods equivalent when it comes to drying filament? Does it only matter what the relative humidity is?

dtgriscom wrote:This is interesting. Using a desiccant removes moisture from the air and leaves the temperature constant; the result is that the relative humidity drops. Using a heater increases the temperature and leaves the amount of moisture constant; the result is that the relative humidity drops. Are the two methods equivalent when it comes to drying filament? Does it only matter what the relative humidity is?

Many use both methods at the same time. Dessicant to absorb the water from the air and a incandescent bulb to increase temperature, net effect is lowered humidity faster than using one method at a time.

The hot end raises the temperature WELL above the boiling point of water, which REALLY reduces the relative humidity (-:
So far that has worked well enough for me (Since late July in Mass) using ABS.
Initially I had a "wiper sponge" that I would dampen and wrap around the filament on the top of the machine.
That worked to keep the filament clean, which is what I was worried about at the time, I also had a dust bag shield over the top of the spool.
I only stopped using the dampened wiper when I read posts about moisture absorption being an issue.

BTW, the printer is in an open area between kitchen and dining room, window air conditioners are run on an as needed basis, humidity in Mass gets fairly high in July and August.

SUMMARY: For ME humidity doesn't seem to be an issue, so I am not going to any great lengths to "solve" it (yet) YMMVG, etc.

For abs it is not a massive problem.

For the exotics humidity control starts becoming a problem.

My hydrometer is saying 30%, does anyone know if that's good enough to dry out nylon?

No. You cannot dry out nylon by storing it in a dry environment. Nylon holds too tightly to water.

In order to dry it, you must use heat, and then once dry, store it in an airtight container.

Doesn't really matter what the RH% is in the container because there isn't enough moisture in the container (even if it's a 5g bucket) to saturate the nylon.

Moisture content of 3% or below is acceptable for nylon. That means for every 1kg, you can have 30g of water and still be in the acceptable range. Even at 100% rh in a 5g bucket, there isn't anywhere close to 30g of water.

Oven at 170-200F for 4-6 hours is your best bet.

Would a microwave work?

No.

g.

I have a 5 gallong bucket with a Gamma lid. (Airtight). Inside, I mounted a gun safe heater (8W), and also put some desiccant in the bucket. Just because you heat the air in an airtight container doesn't remove the moister. It needs somewhere to go so place some desiccant with it. I used some simple "DampRid" that you can find at Home Depot. I place a thermometer and humidity digital gauge inside the bucket. The outside reading was 73 degrees and 54% humidity. After leaving the digital gauge in the bucket container I made for about 6 hours, the reading was 84 degrees and 12% humidity. I will see if I can get some pictures of this setup for you guys. It was really cheap and effective. I am not sure it will "dry out" filament, but I am currently testing that with some Taulman T-Glase that I have. I forgot and left it out for a few days and it started printing really poorly. I figure I will leave it in this very low humidity environment and see what it does.

Hey Dreyfusduke, just as a data point, I also have a gun safe heater in an almost airtight container, i wasn't able to get down to 12% (i was more like 25%), but according to cope (see first page of this thread) - it won't work well. You need to bake it 4-6 hours at 160-200 F. You are obviously welcome to try =) I still had issues after my filament sat in the gun safe drying container after 24h.

I am hoping to get the safe heater to get it up near 90 degrees. 90 degress and 10% humidity would have to do something I would think.

It's not likely to work. Nylon is one of the most used thermoplastics in the world, and drying techniques have been studied for many years.

The minimum I've ever seen recommended for drying nylon pellets is 150F. Most resin manufacturers recommend 180F for 12-18 hours.

Nylon holds very tightly to water, and unless you're pressurizing your container, it's not likely to evaporate at 90F.

I did extensive testing with 25W, 45W and 60W incandescent light bulbs mounted in buckets, as well as different desiccants (standard silica, molecular sieve, rice, etc), and the only consistent method that worked was baking it and then storing it in an airtight container.

I can see making it a vacuum chamber, but not pressure chamber. Lower pressure = lower boiling point. I took some pics. Now gotta figure out how to post them via mobile. Lol

https://www.dropbox.com/sc/u2luldxl7we3 ... HuAHw76Yla

https://www.dropbox.com/sc/n8sesao9z36a ... rsT-VE9x-a

https://www.dropbox.com/sc/6rtces00l6hz ... hsA_vYso7a

I took the lid off quickly and took a picture. Just a few seconds and the humidity begins to climb up over 25%. Removing into apartment atmosphere and it says 62% (currently raining outside). It may not dry filament out, but it sure provides a cheap dry chamber for 8 watts of power.

cope413 wrote:It's not likely to work. Nylon is one of the most used thermoplastics in the world, and drying techniques have been studied for many years.

The minimum I've ever seen recommended for drying nylon pellets is 150F. Most resin manufacturers recommend 180F for 12-18 hours.

Nylon holds very tightly to water, and unless you're pressurizing your container, it's not likely to evaporate at 90F.

I did extensive testing with 25W, 45W and 60W incandescent light bulbs mounted in buckets, as well as different desiccants (standard silica, molecular sieve, rice, etc), and the only consistent method that worked was baking it and then storing it in an airtight container.

Cope413, I'm sure you are familiar with the 5 lb rolls sold by Amazon.com as trimmer line. At 180F is there any concern about warping or distorting the plastic spool that is used
to wrap the nylon filament on? I have no experience in using these or other spools in an oven and I am concerned about the spools being harmed. Thanks in advance!

Yes, I misspoke. I was at one point storing it in a pressurized container (4-5psi), because compressed air is very dry.

Yes, you can get some light warping of the spools, but if you allow the oven to get to temp before putting the nylon in, and make sure that it's in the middle of the oven as opposed to near the top or bottom where the burners are, then there's very little to no deformation of the spools at 180.