Sticky parts - even after alcohol wash

Hi there,

I’ve been using the 99% Isopropyl Alcohol to clean finished prints, but still finding it leaves the prints very sticky/tacky. Does anyone have any suggestions as to how to stop this? Is there a specific time to leave the print in the alcohol, or has anyone found a better way of finishing the prints?

Cheers for any help,

Joe

Joe,

We have found that the following works well:

  1. Give your part a 2 min agitated rinse and a 10min soak in an IPA bath.

  2. Repeat the above in fresh IPA that you replace regularly.

  3. When removing the part from the second IPA bath, use your fingers or a small soft brush to scrub the surface while submerged to dislodge any uncured material still clinging to the part.

  4. Let dry.

You can also use a UV oven to speed up the drying process, but prolonged exposure to UV light can make the part more brittle. Hope this helps!

Jory

1 Like

Hi all,
We have the same problem, especially with a flexible resin.
Using that IPA:
http://uk.rs-online.com/web/p/precision-cleaners-degreasers/2274427/
Finishing as requested: 2min bath, 10min soak and repeat the process.

Any idea?

Regards
Rafal

Hey Rafal! For Flexible resin, some folks have had a lot of success by post-curing their parts in a water bath. Basically, you can stick the part in a tub of water and leave it in the sun for a couple hours after the IPA rinse. I believe we’re going to have full instructions on this method coming up in the near future, but feel free to let me know if you have any questions.

My UV curing box is actually an acrylic 8" diameter jar with UV LEDs facing in, wrapped around the outside of the jar. I fabricated it this way by chance (I was just looking for something large enough to encompass the maximum build volume of the printer, that was made of a transparent material, and this was the best option available to me at Bed, Bath & Beyond), but then realized it was perfect for curing Flexible resin. I can fill it with water, no problem!

I typically “strongly agitate” a print in IPA for about 4 minutes, then again in cleaner IPA for another 3 or 4. This gets rid of all the excess uncured resin, without having to wait for 20 minutes of longer soak. But the surface of the print is always a little tacky. That’s what the post-cure UV box is for. An hour under 24W of ~385-405nm “purple” LEDs and the surface is smooth and free of stickiness.

I’ve also noticed that the supports break free more easily after the print’s been under the UV for a while.

yeah, My made solid white resin has this problem so I just leave it out in the sun for a couple hours, helps a bit, then I just sand it and its not sticky anymore,

Any update on full instructions on this method?