Built a nice filament drying kiln

[Tdeagan]

I got sick of cursing at my foaming filament so I adapted the design from a wood drying kiln and built my self a nice filament drying kiln this weekend.

I used two 100W light bulbs wired in parallel with a dimmer. Built a 3' tall x 12" wide box out of 3/4" foil covered insulation board and foil tape. Used some wire grill and flashing to get the filament out of the direct heat of the bulbs. I put a few holes in the top and bottom to let air move.

The two 100W bulbs are overkill, but the dimmer adds a lot of flexibility. I used a temp sensor on my multimeter to set the heat at 85° C.

I stack the spools, let them bake for 4-6 hours then store them in an airtight cooler filled with heavy duty desiccant.

[drawcut]

Nice setup. It looks scorching hot with the silver reflecting the light bulbs. (just an illusion, I know )Personally I bought a food dehydrator from Harbor Freight that was about $23 on sale and modded it to give enough space for spools. No temp control though. It gets to about 140F which works OK but takes more time. I store with silica cat litter as desiccant.

[plexus]

Nice setup. It looks scorching hot with the silver reflecting the light bulbs. (just an illusion, I know )Personally I bought a food dehydrator from Harbor Freight that was about $23 on sale and modded it to give enough space for spools. No temp control though. It gets to about 140F which works OK but takes more time. I store with silica cat litter as desiccant.

Wow. I feel so dumb. I have my filament in a cabinet with a large amount of desiccant. twice now i have had to reconstitute it, so it is absorbing. But you comment about the dehydrator... I have a frick'n Sedona! I didn't even think to use it to dry filament. it has a large oven-like opening with two fans and digital temp control. duh. I just never thought to use it for that! I got it only a few months ago and have been focused on camping food.

[Tdeagan]

Nice setup. It looks scorching hot with the silver reflecting the light bulbs. (just an illusion, I know )

Thanks. Run one, before I added the dimmer took the temp up to 135°C before I pulled the plug. I had some test filament that got pretty gooey.

Personally I bought a food dehydrator from Harbor Freight that was about $23 on sale and modded it to give enough space for spools. No temp control though. It gets to about 140F which works OK but takes more time.

I hate the idea that I missed out on an opportunity to buy another Harbor Freight goodie. But since I go pretty much weekly, perhaps I'll add this to my list.

I wanted this to be big enough to stack 5-6 spools at a time, in retrospect that seems overkill. But it'll fit a lot of other things as well and I can find uses for it in the shop.

[RetireeJay]

I've just been using the crystal kitty litter in a closed container. A humidity indicator inside the container says it consistently stays below 20%. Maybe it doesn't dry the filament as fast as heat, but it does work over time. Taulman ships their nylon inside closed bags with little desiccant packets so my spools go from dry to dry environment.

[Tdeagan]

I've just been using the crystal kitty litter in a closed container. A humidity indicator inside the container says it consistently stays below 20%. Maybe it doesn't dry the filament as fast as heat, but it does work over time. Taulman ships their nylon inside closed bags with little desiccant packets so my spools go from dry to dry environment.

My attempt to buy the cheap Chinese filament had caught up with me. I kept running out of good filament and trying to use some red 3mm ABS that foamed to 2x+ diameter every time I extruded it. Reading up, folks were suggesting that filament in that condition could take multiple weeks to dry out with desiccant. With better than $120 in filament in this condition, the kiln seemed like a good option.

Now I'm baking all the stuff I left out for months and then putting it in my sealed cooler with desiccant. Ideally it will give me back a bunch of other wise useless plastic.

[drawcut]

I've just been using the crystal kitty litter in a closed container. A humidity indicator inside the container says it consistently stays below 20%. Maybe it doesn't dry the filament as fast as heat, but it does work over time. Taulman ships their nylon inside closed bags with little desiccant packets so my spools go from dry to dry environment.

That's what I use for storage too. But I always seem to forget and leave the nylon filament out once every couple of weeks and the nylon really soaks up the water (especially in the basement where my printer is set up). I like to pre dry any new stuff I get too since it seems to help print consistency.