Keep yer powder dry

..and your ABS filament as well.

Since baking my ABS filament over the weekend, my print quality has improved and I haven't had any more clogs. This is not definitive, but it's suggestive of a problem, and since it can't hurt, I figure I'll start taking some care to dry my filament.

I think what I will do is to use a really large ziplock, perhaps the ones used for vacuum storage, then large dessicant packs. Then I can put the entire spool of plastic into the bag with a dessicant. The spools are fairly large. I see on eBay that ziplock bags as large as 20 gallons are available, so I can probably find some locally as well.

A web search points me to using baked Epsom salts as a dessicant. When baked at 500*F for an hour or so, Epsom salt/magnesium sulfate become anhydrous and is very hydroscopic. Putting it into coffee filters is supposed to make a heck of a good, cheap, and reusable, dessicant pack.
so I can probably find some locally as well.

Yeah, like the storage room. :) We have 10 and 20 gallon ziplocs down there, and I suspect that if you looked around you might find some vacuum storage bags -- we used to have some, and I don't think they've all been thrown away.
I knew there were one or two vacuum storage bags there. I didn't know there were 10 and 20 gallon ziplocks; until I checked I didn't know if there was such a thing outside of industrial supply. I'ma gonna need 12 to 20 bags.

Edited at 2012-02-07 06:56 pm (UTC)
I'm intrigued with the idea that a material commonly used in plumbing is hydroscopic, or at least sensitive to the internal moisture.

However, if you were to tell me that it has to do with differences between the ABS supplied for 3D printing and the ABS used in drainage pipes, I would not be surprised.
The stuff used in plumbing has resins in it, from what I understand. Also fillers.

I really don't know what's going on internally. I didn't try this for a long time because I didn't think the stuff could absorb water either, but I got to the point where I was just going to throw the crap away anyway, so I tried it.
It's the polybutadine, the B in ABS. It doesn't absorb a ton of water, which is why it is fine after it is formed, but when you are intending to melt it, the water inside will boil and cause issues ranging from cosmetic (splay) to impossible to work with. </p>

Polycarbonate has a similar problem, and the same solution - heat it up to drive off the moisture, then form it.