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Great Prints regardless of humidty

Discussion in 'Mods and Upgrades' started by Lance Weston, Jul 14, 2019.

  1. Lance Weston

    Lance Weston Active Member

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    My basement is 60% humidity in the summer with the dehumidifier running full blast. I could not make decent prints. I purchased a couple of aluminum air tight army surplus boxes with purge valves. I removed the purge valves, tapped the boxes for 1/2 NPT. Using the rubber washer from the purge valve and Blue Block sealant I installed a valve and a hose adapter. I added desiccant. I had an old vane vacuum pump laying around and sucked the air out of boxes. My prints were better but not perfect.

    Desiccant is designed to bring the moisture down to 25%-35% RH. This is only good for 8 hours of printing before I notice degradation.

    I then baked all of the plastic for 3 hours at 150F before putting into the box and 1 1/2 hour at 150F (in a convection oven/microwave) right before use. Even the least expensive plastic gives very nice prints. The 28" of vacuum is not enough to boil the water out of the plastic and probably just the sealed case is enough. This was good for 24 hours of printing before degradation.

    I am now able to print out all of the partial rolls that I thought were junk.

    Moisture seems to be the root of all printing problems.

    I just ordered a deep vacuum pump for $12 from eBay. A deep vacuum should boil out the moisture with no heat required.

    The case: http://armysurpluswarehouse.com/mil...rized-case-night-vision-goggles-storage-case/

    ball valve:
    https://www.amazon.com/gp/product/B07CNZJLYK/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

    hose fitting:
    https://www.amazon.com/gp/product/B07RWCKR27/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

    vacuum pump:
    https://www.ebay.com/itm/3-5CFM-1-4...127&pg=2054502&_trksid=p2054502.c100227.m3827
     

    Attached Files:

    mark tomlinson likes this.
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    I keep mine stored with desiccant until it goes on the spool for printing, but even then we had to use a dehumidifier to drop the RH down to 45% or so for it to be a workable environment. :)

    Good job!
     
    Geof likes this.
  3. Lance Weston

    Lance Weston Active Member

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    It is easy to fool oneself with short term data. I have now been using this for awhile and I believe all of the improvement was due to desiccant in a sealed box. I have not used the vacuum in months and found no difference. I would not bother with the vacuum.
     
  4. tkoco

    tkoco - -.- --- -.-. ---
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    @Lance Weston , have you tried a room dehumidifier to bring the ambient humidity down to the 40% range? What size desiccant modules are you using?
     
  5. Lance Weston

    Lance Weston Active Member

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    I have a dehumidifier running set to 35%. I have test strips around the room indicating 35% to 45% so figure 40%. I have 1 printer using the the filament straight from the box with desiccant, but then the filament just sits on the back of the printer. I get a reasonable finish with Sunlu PLA+. I have 2 other printers feeding the filament from a dehydrator which is set to 15% humidity. With the same filament I get a better finish with the dehydrator.

    It is winter here now and humidity is not a problem. I had started to look for a solution in the spring as the humidity went up. I am very fussy on finish and would lose the "magic". Feeding the filament from a dehydrator box is the best year round solution. It takes a week in the box in the spring before I can print. Some filaments like Sunlu come straight from the factory filled with moisture and require the week.
     
  6. tkoco

    tkoco - -.- --- -.-. ---
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    Sounds like you have it under control. I use 2 each, 50 gram packets of desiccant in a zip lock bag with a humidity indicator strip. One setup per each spool of filament. Humidity runs around 15 to 20% inside each bag. Then all filament bags are stored in a large container with a room sized desiccant bucket inside. The two stages of desiccant keeps all the spools of filaments very dry. I pull out only the spool of filament needed to print the model(s).
     
  7. Lance Weston

    Lance Weston Active Member

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    I bought orange desiccant from Amazon (https://www.amazon.com/gp/product/B07Q6RQ5VD/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1) which was way oversized for a container that could only hold 9 rolls. When I print, I keep printing until the roll is exhausted which takes about a week. So the governing humidity is the room.
     

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