I am using a Formlabs 3 resin printer and I am would like to create a bottle design with a cap. my objective is for the cap to completely prevent any liquid from going in or out of the bottle (even it was shaken) and also prevent dry air from seeping in and effecting the moisture inside.

(Note: I am not planning to cure my print with UV light as I feel it ruins the smoothness and flexibility of the model. tell me if I am wrong)

Is that possible by just printing? or do I need some coatings or extra steps?


1 Answer 1


Yes and no

If you can print very tight tolerances and the bottle itself does deform a tad to press into the cap, then yes, you will get a perfect interference fit.

If you want to go absolutely sure, a little seal of rubber into which the mouth of the bottle presses can add the last bit needed. alternatively, a viscous grease on the threads can act as a sealant.

In case you want to pretty much seal the bottle forever and not remove the cap, you might just as well add a few droplets of liquid resin or glue to the threads of the cap before screwing it on, then make sure that it sets and seals. Loctite is one such sealing glue often used.


However you are wrong not to cure your model: unless cured, the model is not safe to the touch without gloves as the bonds are not set and liquid resins are dangerous skin irritants. If you want to use the flexibility of not fully cured resin to seal your containers, you might want to seal the bottle with the raw caps and then cure the combined item right after.

  • $\begingroup$ I am washing the printed part with Isopropenyl. is that not enough? $\endgroup$ Commented Feb 9, 2022 at 17:32
  • 2
    $\begingroup$ @AnwarElhadad it is not. Bonds inside the item are not set and the surface of the resin can have very reactive chains that are bonded on one side, but aggressively react still. $\endgroup$
    – Trish
    Commented Feb 9, 2022 at 17:34
  • 1
    $\begingroup$ Thank you. Currently, I am curing under 60 C° for 3 minutes. This causes my clear resin to be not as clear. any tips! $\endgroup$ Commented Feb 9, 2022 at 17:43
  • $\begingroup$ @AnwarElhadad sadly no, but that'd be a good followup question: how to prevent the surface from clouding on a 3D print? $\endgroup$
    – Trish
    Commented Feb 9, 2022 at 17:51
  • $\begingroup$ I like the o-ring idea. Could use a rubber garden hose seal from the hardware store if it’s the right size, or model in a channel for rubber O-ring from the plumbing section. You leave a little empty space in the channel for the cross section of the o-ring to deform/flatten. 10%-30% compression is good. $\endgroup$ Commented Feb 10, 2022 at 5:27

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