Choosing castable resin

[Storen]

Currently I am printing with WaxCast from Makerjuice. The print quality is excellent however I can’t find a way to cast successfully.

I’ve tried different investments, burnout cycles, alloys, cast temperatures, curing times, etc. Whatever I do the casts come out with major surface defects.

I even sent the models to several reputable casting houses. Their results were actually worse than mine.

When I cast carving wax models they always come perfect so I suspect the main problem is the resin.

I know the B9 Emeralrald and Yellow resins cast well, unfortunately their fumes are toxic (reproductive toxicity) and should be used only in well ventilated areas, or with expensive professional fume extractors, or require constant wearing of respirator when working in the same room with the printer… None of that is feasible for me so I am looking for a safe alternative.

The FormLab (blue) castable resin is not as dangerous as the B9’s so I am wondering if someone had a chance to cast models printed with both type of resins. How they compare in terms of burnout / castability?

Do you know of any other safe resin that casts well and it is freely available for purchase?

[rkundla]

I never was able to cast WaxCast properly, so I have moved to B9 Emerald. I still have a bottle and a half left. If they ever figure out a better way to burn it out, I'd be happy.

If someone tells you they have a safe 3D printing resin, they are not telling you the truth. All of the chemicals in 3D printing resin have some sort of MSDS warning associated with them, some more toxic than others, but there are risks associated with all of them - its the nature of the chemistry. Whether B9 is really a reproductive hazard depends on whether or not they are over-protecting themselves from liability in case something happens. If you have serious concerns, they should be able to tell you what chemical in particular is covered under the MSDS and point you to studies that show the hazard and under what conditions it could impact your use.

I find the fumes from B9 Emerald to not be as strong as other non-casting resins like MakerJuice G+. I wear nitrile gloves when handling it to help prevent any sensitivity issues and I do not leave resin to sit out exposed any longer than necessary. Ventilation is beneficial to help remove fumes if the area your printer is located in is small and has no natural air flow.

[mongerdesigns]

I agree. There is no such thing as a 100% safe resin. All resins should be handled with care when they are liquid (uncured). Some resins smell (fumes) worst than others because of the chemical composition. Resins have about the same toxicity like most household chemicals, so they are relatively safe if handled properly.

To be safe, always use the resins in a well ventilated area, keep away from eyes and skin and wear disposable gloves (nitrile).

[Storen]

If someone tells you they have a safe 3D printing resin, they are not telling you the truth.

You are probably right, however we can divide them into 2 categories:
1. Those that cause minor skin and respiration irritation and do not present a real threat in normal use.
2. And those that cause cancer, birth defects and reproductive problems.

B9's resins unfortunatly classifies as the second kind. Are they over-protecting themselves? I don't know, I'am not an expert but I feel it would be unwise to ignore the big red warning sign in their SDS.

There is no such thing as a 100% safe resin.

I agree but I think we should differentiate between skin irritation, cancer and birth defects. I hope the new Solus castable resin which we are all patiently waiting for is not going to be as dangerous as the B9's resins.

One more thing - Do you know if these safety warnings apply only to the resin in liquid form? How about breathing the fumes of the cured resin from the burnout process?

[rsaldivar]

this is what I do , I primarily use waxcast because the green gives me too many fails , so after growing I rinse in acetone for a few seconds , then I put in my oven at 150 f overnight with the supports still on , then in UV light without supports for one hour ea. side ( 2 hours total) or put on a turntable , I use these

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

then I tree up and after that I dip in this 5 times
http://protoproducts.com/Catalog.php...egory=14185011

then I invest with plasticast from R&R , 38 to 100 , 3 hours to sit , 3 hours at 350 f , 1.5 hours at 700 , 3 hours at 1400 then down to cast temp ( I use 800 f ) but if its filigree maybe 900 - 1000 , I cast at least once a week 3 crusibles or so and get good results

yes takes long , but this is how I get good results
hope this helps

[Storen]

this is what I do , I primarily use waxcast because the green gives me too many fails , so after growing I rinse in acetone for a few seconds , then I put in my oven at 150 f overnight with the supports still on , then in UV light without supports for one hour ea. side ( 2 hours total) or put on a turntable , I use these

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

then I tree up and after that I dip in this 5 times
http://protoproducts.com/Catalog.php...egory=14185011

then I invest with plasticast from R&R , 38 to 100 , 3 hours to sit , 3 hours at 350 f , 1.5 hours at 700 , 3 hours at 1400 then down to cast temp ( I use 800 f ) but if its filigree maybe 900 - 1000 , I cast at least once a week 3 crusibles or so and get good results

yes takes long , but this is how I get good results
hope this helps

Thanks so much! It is a light in the tunnel.
I am going to order the React-Shun today and give this resin one more try with your burnout schedule.

[rkundla]

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
http://protoproducts.com/Catalog.php...egory=14185011

I don't know about everyone else, but each of these links show up as broken to me.

You have a lot of process there to cure the daylights out of that resin. Not only do you use UV and oven, you also have to use barrier coatings to get a good print. I am not sure what you do with the Amazon links - more barrier?

If you have to jump through hoops like that to use WaxCast, that would kill your productivity in a higher volume shop where time is money.

[rkundla]

Okay, I decided to try to do some Googling to better understand this reproductive toxicity is all about.

http://www.schc.org/assets/docs/ghs_inf ... 4-4-16.pdf

This is a flyer from the Society for Chemical Hazard Communication describing that a Category 2 hazard is a "suspected" hazard, but not a known one. It is a "warning" versus a "danger" notification. Still something to be concerned about I guess.

Now, what component in the resins causes this toxicity?

https://support.ember.autodesk.com/hc/e ... r_2015.pdf

The Autodesk Ember PR48 open-source resin is marked as being a Category 2 toxicity and here is the table:

The photo initiator according to various blogs is 2,4,6-Trimethylbenzoyl-diphenyl-phosphineoxide (TPO)

Here is a link to a study on the health impacts of TPO: http://ec.europa.eu/health/scientific_c ... _o_149.pdf

Interesting to see that TPO is used in UV nail color (acrylic?) curing. They had a whole section dedicated to testing in that environment.

You can read the results and come to your own conclusion, but the tests involved high concentrations of TPO given orally to mice over a long period of time to see the effects described in the document. At the small percentages in the resin and the limited exposure method I don't think the risk is great enough (personally) for me to stop using the resin.

[Storen]

Okay, I decided to try to do some Googling to better understand this reproductive toxicity is all about.

http://www.schc.org/assets/docs/ghs_inf ... 4-4-16.pdf

This is a flyer from the Society for Chemical Hazard Communication describing that a Category 2 hazard is a "suspected" hazard, but not a known one. It is a "warning" versus a "danger" notification. Still something to be concerned about I guess.

Now, what component in the resins causes this toxicity?

https://support.ember.autodesk.com/hc/e ... r_2015.pdf

The Autodesk Ember PR48 open-source resin is marked as being a Category 2 toxicity and here is the table:

pr48_tox.jpg

The photo initiator according to various blogs is 2,4,6-Trimethylbenzoyl-diphenyl-phosphineoxide (TPO)

Here is a link to a study on the health impacts of TPO: http://ec.europa.eu/health/scientific_c ... _o_149.pdf

Interesting to see that TPO is used in UV nail color (acrylic?) curing. They had a whole section dedicated to testing in that environment.

You can read the results and come to your own conclusion, but the tests involved high concentrations of TPO given orally to mice over a long period of time to see the effects described in the document. At the small percentages in the resin and the limited exposure method I don't think the risk is great enough (personally) for me to stop using the resin.

Great post. Thank you for researching this!

Is it certain that B9 resins contain Trimethylbenzoyl-diphenyl-phosphineoxide (TPO) and this is the reason for the reproductive toxicity warning? Could it be something else? Is it possible that other brands also use TPO in their resins but do not mention that in the SDS?

[M-Williams]

We tried all kind of stuff in the peace and love era,and we are still here kicking. you should be fine as long as you use your resin exclusively for printing. Marc