As much as I write about 3d printing, I have not written much about the 3d printing type I wish so badly could do, but probably never will: resin printing. The reason for this is that I am allergic to resin. Or more specifically: the solubles used in resins, acrylics and other plastics.
Allergies are not something you are born with, as far as I know. I am not a doctor, I think you could inherit allergies? I really don;t know, I do know that the allergies I have all showed up at some point in my life and exposure to the allergens made it worse. There is a treatment for hayfever where you get exposed, I did that for over 2 years in my teens, and it made it worse. Do not let that be a reason for you to not do the therapy, as the allergy-doctors in the hospital explained: I am an edge case and they were sorry they made it worse. Well, that is hayfever, I have excellent medications against it and it barely bothers me. But it does give some indication on how allergies in me can evolve like wildfire.
Now, that resin allergy I have did not start with printing, it started with pretty nails.
I have always been a bit of a clumsy person, all through my life I had my fingers stuck between doors, garden gates, crates, anything with hinges, drawers and there was that day that I closed and locked (with the button) my car door and I had my fingers stuck and I needed to get my keys from my pocket to free myself. Yeah, that happened. So, several of my fingers have damaged nail roots, the part where the nail is formed. Those nails grow with ridges and are very prone to splitting. They split very far, to the point where it hurts a lot and I have to wear finger band aids to protect them from ripping ever further.
Many years ago I got a solution through a friend who wanted to practice making acrylic nails. I never really wanted those, I am never really busy with my looks and those nails seemed like a hassle. But the acrylic nails glued my crooked nails together, completely prevented ripping and had a pretty color as the cherry on the cake. I would have taken the cake without that cherry, but colors and glitter make me happy. So, I had acrylic nails and later on I got gel nails, with the not-smelly goo that hardens under UV light.
Then one day, completely out of the blue, my nails started to hurt and feel weird. Like there was pressure under them. My nails fell off and what was under them looked very nasty. My nail-salon lady and my initially thought it was some fungus, but after it had all grown back and looked healthy I had the same response within a day from the new nails.
I visited my doctor, got send to a dermato-allergist and had a whole week of extensive testing done. Partly because there were a lot of chemicals to test for, and partly because there was a classroom of upcoming dermato-allergists who also thought this was interesting. I learned a lot, as things got explained, which was very cool actually.
The results were predictable with the resins in mind, but I am also allergic to some preservative that is used in expensive perfume (never used that), some stuff that is used in the fabrication of car tires (no idea where I picked that up) and some other funny chemicals that were common when I was a kid, like in cough-syrup but are no longer in use so nice to know, not relevant.
What was relevant was the list of resin components I am allergic to if they are in the liquid state;
2-hydroxyethyl metacrylate
2-hydroxypropyl metacrylate
ethylene glycol dimethacrylate
tetrahydrofurfuryl metacrylate
triethyleneglycol dimethacrylate (TEGDMA)
And this came with a warning: these specific chemicals are almost never mentioned as ingredients, but the names of the group they are in. Manufacturers may not always be consistent in the chemical from the group that is used, though the safety material data sheet for the batch should always give the correct chemical.
Even so, if the product I want to use does not contain any of these, I am clearly prone to develop allergies to these types of chemicals and I should be aware that contact with those that I am not allergic to yet most likely will result in me getting that allergy sooner rather than later.
About half a year ago I had found some nail-stuff without the hema-chemicals (2-hydroxyethylmethacrylaat and/or hydroxyethylmethacrylaat), and since I had 3 fingers wrapped up in bandaids, some pain and a lot of frustration I just decided to give it a try. It took my body about 3 months to start throwing the allergy-hissifit again, so whatever was in that gel, I can not have that anymore either.
So basically: if it has ‘metacrylate’ in the name I should avoid it.
So no resin printing.
The chemical blisters I had under my nails and on my back during the tests were no fun, but the idea of what might happen inside my lungs if I would inhale this…. I rather not find out.
Or as the doctor said it: “Please do not have a hobby that tries to kill you!”.
Not being able to have a resin printer and print my own mini’s is a bit of a bummer.
But not being able to print mini’s is really the least of my worries. I can avoid the allergens, but I do need to always make folks in any (medical) situation aware of my allergies because there are a lot of medical applications nowadays that use UV hardening resins. Like dentist fillings, bone-cement (for implants and emergencies), hearing aids, and a lot more. So I need to always be a bit aware of this, since UV-resins are being used more and more.
As for the mini’s, I have a lot of them because I have a great friend with a resin printer and no fdm printer who prints mini’s for me (and makes sure they are properly cured) and I print terrain and bigger things on my fdm printer for her. So we still both have a lot more than we can ever paint, and we are having a lot of fun with that together.
A final note: if you know of any way to repair nails in a way that does not involve using UV-hardened materials, nail polish or nail glue (that now also all have some type of acrylic/resin in them) please let me know!