<p>SLS prints from nylon are somewhat porous. This means, that they will let a stabilizer soak into the outer surface to some degree.</p>

<p>What kind of stabilizer is needed is depending somewhat on the properties you want, but generally I believe these might be useable depending on the viscosity:</p>

<ul>
<li>2-component resins could be used, but they are usually very viscous. Their viscosity, however, is dependent on the exact type and mixture and could be altered by temperature.</li>
<li>1-component (<em>air-hardening</em>) resins or resin lacquers can be thinned to achieve a solution into which the item is then dunked and dripped off. How much thinner is adviseable depends on the exact material</li>
<li>Nitrocellulose lacquer, like it is used in guitar building, is extremely fluid and could be used for treatment via dunking.</li>
<li>PU lacquer could be used too.</li>
</ul>

CC BY-SA 4.0
2019-10-19T11:03:14.790Z
2019-12-18T13:28:48.507Z
2019-12-18T13:28:48.507Z
Trish
<p>We are attempting to print some single-use prototypes using an SLS printer. The parts must be somewhat water-resistant for short-term usage, but do not have to been waterproof entirely. </p>

<p>According to this page, <a href="https://www.3dhubs.com/knowledge-base/post-processing-sls-printed-parts/#water" rel="nofollow noreferrer">Post processing for SLS printed parts - Water tightness</a>, any silicone type or vinyl-acrylate sealant should work well, but I was hoping that the Stack users here might have some specific suggestions. </p>

<p>Does anybody have specific recommendations for sealing SLS prints?</p>

CC BY-SA 4.0
2019-10-17T18:15:15.197Z
I think it's going to depend on two things: what is the material made out of (for the print) and what are you trying to seal it against? Water is going to be different from alcohol which would be different from oil. If you wanted to seal it against acid, that'd be an ever bigger challenge.
Pᴀᴜʟsᴛᴇʀ2
CC BY-SA 4.0
2019-10-17T18:20:42.747Z
All of these prototypes will be tested in water. Further prototypes will be constructed of cement and used with an oil-based fluid. Material is “Versatile Plastic” from Shapeways. I believe it is a Nylon.
JPeroutek
CC BY-SA 4.0
2019-10-17T18:23:11.917Z
clear spray acrylic sticks to most things and is completely waterproof once dry.
dandavis
CC BY-SA 4.0
2019-10-17T18:27:07.050Z
Most SLA resins are water resistant, while nylon SLS could be dunked in resin to get it into all the print.
Trish
CC BY-SA 4.0
2019-10-17T18:30:20.267Z
@Trish Wouldn’t a resin bath require a UV laser to harden it?  We opted to use SLS over SLA due to a 300% price difference.
JPeroutek
CC BY-SA 4.0
2019-10-17T18:34:29.067Z
@dandavis Something skin to this? https://www.amazon.com/dp/B001K65K26/ref=cm_sw_r_cp_api_i_KYiQDbZ2BCYNR
JPeroutek
CC BY-SA 4.0
2019-10-17T18:35:40.033Z
@JPeroutek no, most Resins are actually not UV curing: Most resins that are mixed with hardeners, which then could be used as coating. Epoxy, polyester and Styrene-acrylonitrile Resins are such options. Another option could be Polyurethane.
Trish
CC BY-SA 4.0
2019-10-17T18:35:57.220Z
yes, that would work, but seems vastly overpriced. Rustoleum clear "spray paint" is the same thing, but imho, better than krylon, who seem to be marketing it as something more special than what it is, clear coat, that you can buy for $5/can at walmart or home depot. Clear nail polish works too btw, i use it as conformal coating in outdoor projects.
dandavis
CC BY-SA 4.0
2019-10-18T17:27:02.227Z
@Trish some of our geometries are quite small, with around .6 mm gaps that need water-proofing. Picture a small 1” diameter fan with about 15 overlapping tilted blades. Will the resin block those fluid paths?  In my experience, epoxies are very viscous thick fluids.
JPeroutek
CC BY-SA 4.0
2019-10-18T17:33:45.307Z
@dandavis Perhaps repost your comments as an answer?
JPeroutek
CC BY-SA 4.0
2019-10-18T17:57:56.957Z
@JPeroutek it could, but the viscosity is dependant on the ammount of hardener and the exact mixture. Some resins change viscosity based on temperature. 0.6 mm is very tiny though... 1 component Resin-laquer, thinned a little, could be an option.
Trish
CC BY-SA 4.0
2019-10-19T01:44:04.910Z
@Trish could you possibly submit that as an answer?
JPeroutek
<post-processing><sls><water-resistance>
Sealant to increase Water-Resistance of SLS print
JPeroutek
# Sealant to increase Water-Resistance of SLS print

(Asked by: username_0 on 2019-10-17)

We are attempting to print some single-use prototypes using an SLS printer. The parts must be somewhat water-resistant for short-term usage, but do not have to been waterproof entirely.

According to this page, [Post processing for SLS printed parts - Water tightness](https://www.3dhubs.com/knowledge-base/post-processing-sls-printed-parts/#water), any silicone type or vinyl-acrylate sealant should work well, but I was hoping that the Stack users here might have some specific suggestions.

Does anybody have specific recommendations for sealing SLS prints?

**Tags:** post-processing, sls, water-resistance
> **Comments:**
> **username_1**: I think it's going to depend on two things: what is the material made out of (for the print) and what are you trying to seal it against? Water is going to be different from alcohol which would be different from oil. If you wanted to seal it against acid, that'd be an ever bigger challenge.  
> **username_0**: All of these prototypes will be tested in water. Further prototypes will be constructed of cement and used with an oil-based fluid. Material is “Versatile Plastic” from Shapeways. I believe it is a Nylon.  
> **username_2**: clear spray acrylic sticks to most things and is completely waterproof once dry.  
> **username_3**: Most SLA resins are water resistant, while nylon SLS could be dunked in resin to get it into all the print.  
> **username_0**: @Trish Wouldn’t a resin bath require a UV laser to harden it?  We opted to use SLS over SLA due to a 300% price difference.  
> **username_0**: @dandavis Something skin to this? https://www.amazon.com/dp/B001K65K26/ref=cm_sw_r_cp_api_i_KYiQDbZ2BCYNR  
> **username_3**: @JPeroutek no, most Resins are actually not UV curing: Most resins that are mixed with hardeners, which then could be used as coating. Epoxy, polyester and Styrene-acrylonitrile Resins are such options. Another option could be Polyurethane.  
> **username_2**: yes, that would work, but seems vastly overpriced. Rustoleum clear "spray paint" is the same thing, but imho, better than krylon, who seem to be marketing it as something more special than what it is, clear coat, that you can buy for $5/can at walmart or home depot. Clear nail polish works too btw, i use it as conformal coating in outdoor projects.  
> **username_0**: @Trish some of our geometries are quite small, with around .6 mm gaps that need water-proofing. Picture a small 1” diameter fan with about 15 overlapping tilted blades. Will the resin block those fluid paths?  In my experience, epoxies are very viscous thick fluids.  
> **username_0**: @dandavis Perhaps repost your comments as an answer?  
> **username_3**: @JPeroutek it could, but the viscosity is dependant on the ammount of hardener and the exact mixture. Some resins change viscosity based on temperature. 0.6 mm is very tiny though... 1 component Resin-laquer, thinned a little, could be an option.  
> **username_0**: @Trish could you possibly submit that as an answer?  

---

## 1 answers

### Answer by username_3 on 2019-10-19. Score: 1 | Accepted answer

SLS prints from nylon are somewhat porous. This means, that they will let a stabilizer soak into the outer surface to some degree.

What kind of stabilizer is needed is depending somewhat on the properties you want, but generally I believe these might be useable depending on the viscosity:

* 2-component resins could be used, but they are usually very viscous. Their viscosity, however, is dependent on the exact type and mixture and could be altered by temperature.
* 1-component (*air-hardening*) resins or resin lacquers can be thinned to achieve a solution into which the item is then dunked and dripped off. How much thinner is adviseable depends on the exact material
* Nitrocellulose lacquer, like it is used in guitar building, is extremely fluid and could be used for treatment via dunking.
* PU lacquer could be used too.


---

