Black V5 Resin Becoming Soft and Easily Damaged After Form Wash Solution — Anyone Else Experiencing This?

General Discussion
1

We recently invested heavily into the full Formlabs ecosystem (Form 4, Form Wash, Form Cure, Black V5 resin, etc.) and have been struggling with a major issue where our Black V5 parts become extremely soft, easily scratched, and develop white flaking or stress marks almost immediately after processing.

Our workflow has been exactly as recommended by Formlabs:

• Printed on Form 4 with Black V5
• Washed in fresh Formlabs Washing Solution
• Tried wash times of 5, 10, and 20 minutes
• Rinsed in clean water for 1 minute per Formlabs guidance
• Air pressure dried and also tested additional air drying up to several hours
• Cured according to recommended Black V5 settings on the Form Cure

Despite this, the parts:
• Feel soft enough to dent after washing
• Scratch very easily with fingernail pressure
• Show white residue/flaking when scratched or flexed
• Sometimes become brittle if cured longer
• Occasionally have a “snowflake” or chalky appearance

We are trying to determine whether:

  1. The Form Wash Solution is not interacting well with Black V5

  2. The rinse/wash process is over-saturating the surface

  3. The resin itself is unusually sensitive

  4. Others are experiencing the same thing

Has anyone else seen similar behavior specifically with Black V5? If so:
• What wash times worked best for you?
• Are you using Form Wash Solution or IPA?
• How long are you drying before cure?
• Did you find a solution to the softness and white scratching issue?

At this point we are trying to figure out whether this is process-related or a material limitation.

1 Like
2

Sounds similar to my issues’?

3

Thanks for reaching out! I’m sorry to hear you’re facing issues with the material properties.

The softness you describe could be related to the parts being exposed to the washing solution for too long. Could you clarify how much time passes between washing the parts in RWS and rinsing in water? Ideally, they should be rinsed immediately.
If possible, could you also provide a photo of the parts to illustrate the white residue? This will help our team investigate the issue.

4

We wash the parts for 5 minutes in RWS and then immediately rinse in clean water for 60 seconds.

5

Thank you for clarifying!

After checking with our team, it seems that for the parts you’re printing, drying with compressed air is not the best solution. Resin parts exhibit softness when they are not fully dried, so the compressed air treatment most likely isn’t sufficient for drying parts completely in this case. Depending on the part geometry, the force of the compressed air can also risk damaging parts while they are in this softer state.
Our recommendation is to try out a full air dry, which can take up to 12-24 hours, depending on the part. Some customers have also had success using dehydrators.

Please let us know if these workflow adjustments resolve the softness. As for the other effects you mentioned, they are expected for the material - longer curing typically increases the brittleness of resin materials.

I hope this helps!

1 Like
6

Hi there @Eluna32

I figured I’d throw my unsolicited thoughts your way to see if it helps you at all :slight_smile:

Also, please note, I have not used Black v5 specifically, but I have been printing for resin for quite a while and the majority of formlabs resins behave the same in terms of post-processing.

I have moved away from washing with anything else except IPA and it simply seems to be the best for not only formlabs resins, but all 3D printing resins in general. A few things stand out to me with the symptoms you’re describing:

The soft and easily scratched issue

-I have noticed with all “green” resins they must be handled with care, dropping them, scratching them, washing them with with other parts etc, can lead to scratched and dents. In fact, I’ve had a waffled pattern show up from a wash basket on some of the parts I’ve printed with the Tough series of resins by letting them dry IN the wash basket.

-This can go hand in hand with parts being easily scratched even AFTER curing for up to 24 hours. I let cured parts generally “rest” after curing overnight. I have not found a 3D printing resin that won’t, to some extent, be able to be scratched with a fingernail and leave a visible mark.

Show white residue/flaking when scratched or flexed

This sort of goes along with the points I mentioned above - whiteness or flaking when flexed pre-cure is not uncommon. Again, we’ll want to ensure we’re taking care when handling the parts. Post cure, I don’t believe Black v5 is as flexible as the Tough series, but you can absolutely get white stress marks from bending it where it’s not designed to bend. My understand is it’s more designed for rigid parts which are not designed to flex under stress. It’s more along the lines of a standard resin.

Sometimes become brittle if cured longer

Overcuring is 100% a thing and brittleness is a big sign of overcured resin. I recommend sticking with the formalbs recommended settings for this resin.

Occasionally have a “snowflake” or chalky appearance

This can be a sign your wash solution is saturated and needs to be changed out. In most situations, you’ll notice white “dust” collecting in areas with low wash solution flow such as cavities, depressions in the part etc. Undissolved resin will basically coat your part and it can be quite ugly.

Here is my workflow for formlabs resin printed parts:

  • Remove parts from the build plate. (I have a flexi release plate is amazing and I highly recommend one if you don’t have one!)
  • Parts go into an ultrasonic washing machine with IPA. (I have ventilation set up for this and there are HUGE debates online about whether or not you should use IPA in an ultrasonic. I’m not going to debate those points here)
  • Parts are removed from ultrasonic, dried with compressed air and inspected. If parts are satisfactory, they are de-supported and go right into a secondary clean IPA wash.
  • Parts are usually washed for 15-20 minutes
  • Parts are removed from clean IPA wash and once again dried with an air compressor
  • Parts are left to air dry anywhere from 5 to 12 hours
  • Parts are inspected again and cured in the FormCure as per settings on the FormCure
  • Parts are removed from FormCure and inspected for warping and left to “rest” overnight

I know there is a lot of information in this post, so feel free to tag me if you have any questions and I’d love to help out where I can!

Edit - I never use water to wash parts. Unless the resin is stated to be water-washable, I would not use water to even rinse off IPA. Not sure about wash solution, but I would imagine it’s along the same lines. Air drying is the way!

1 Like
7

How saturated was your IPA? I’ve noticed resin can 100% absorb IPA and cause swelling and thin-walled parts to get all sorts of goofy. A 2-stage wash setup will mitigate of a lot of issues, though not everyone has space for that sort of setup. It looks like you were left hanging since last year!

Did you ever get it resolved?

8

Thank you for the detailed explanation and information. I tried washing the parts in IPA, drying them with compressed air, rewashing them in clean IPA, letting them air dry for 18 hours, and then curing them for 1 minute. The parts still develop white scratch lines from light surface contact.

At this point, it honestly feels impossible to print anything with Color V5 or Black V5 and achieve a durable, solid surface finish. I invested heavily in the full Formlabs ecosystem, expecting professional-grade results, so this has been extremely disappointing and frustrating. Right now, I feel misled by the expectations versus the real-world outcome.

1 Like
9

Curing for 1min is not sufficient. Refer to the recommended curing steps FL has for your cure station.

10

Form Cure V2 time and temperature settings show 1 min for Black V5 and 1 min Color V5.

11

Try 5mins at 60C with a 5-7min preheat to help mitigate warping.

1 Like
12

Won’t that make the part extremely brittle?

13

Nope. That is how I run all the general purposes resins and I’ve had good results.

1 Like
14

Thank you!

15

Do you have any recommendations on how to wash and dry? I can’t seem to get rid of the white residue when I scratch the part.

16

I typically do a 2 stage wash with 2mins in RWS as the “dirty” basin and then 3-4mins IPA for the “clean” wash (parts still attached to platform and/or rafts). I have access to a lot of 99% IPA so we swap pretty frequently to ensure it is fresh. Then dry with compressed air or use a dehydrator if you have access to one (works great for elastomeric resins). I typically remove supports at this point. To minimize scratching try using some flat-cutters and careful support placement to make sure the supports can pull away without contacting the part as easily as possible. The uncrured “green” state of the parts is a lower durometer which is giving the soft surface and easy scratching. Once fully cured the parts should get harder. The listed hardness of Black v5 is 67D, and fingernails are somewhere between 60-75D, so slight variations either way means you can scratch those polymers with your fingernails either way. I primarily use Grey v5 which is listed as 82D, might account for some of the differences…perhaps Black v5 is particularly susceptible to scratching due to the shore hardness and the color making scratches pop.

I’m not totally sure what the “chalky” appearance is…kinda makes me wondering if there is pigment or old resin flying around in the wash station (White v5 or Rigid for example). Some pictures of this would be helpful.

17

Here is a photo showing the scratching results after following your latest recommended process (5 minutes at 60°C with a 5–7 minute preheat).

The part was washed for 5 minutes in fresh IPA and then air dried under a ceiling fan on mesh trays for approximately 20 hours to allow for maximum airflow and solvent evaporation. After drying, the part was cured for 5 minutes at 60°C with a 5–7 minute preheat. The part was then allowed to cool down for 1 hour before performing the scratch test.

Unfortunately, the surface still develops white scratch marks very easily. At this point, none of the recommended process changes appear to be resolving the issue.

Part Scratched
Part Scratched1475×1586 362 KB

18

Interesting. What are you scratching the part with?

19

plastic clip

20

What kind of plastic clip? In particular, is it a white plastic clip? Maybe try a paperclip or something metal instead? This looks vaguely like the dust I see on grey parts after sanding but that washes off with no issue.