Simple Sourcing Epoxy, Silicone?

Does anyone have a nice, current list of suppliers that are friendly to small orders, not asking questions, and providing quality DIY soft/polymer/plastics?
Looking at some of the bigger names can be... intimidating...
https://nusil.com/en/productsearch#life-sciences?segment=MedicalImplant

Wouldn't know where to start!

Comments

  • Atom Adhesives
    They have medical grade epoxy which has been tested by at least one grinder on this site. This can also be found on Amazon for even easier shipping. eBay too, if I recall.

  • Awesome. I think the adhesives seem a bit easier than the Silicone. Sites keep them behind walls of salespeople. I'm really intent on casting/encapsulating something, and will need it.
    I'm going to check out atom. If i can't cast in silicone, i am considering usp vi tubing, with the component inside, filled/sealed with epoxy. Thanks!

  • I previously ordered some Atom Adhesives epoxy directly from the company and they delivered very fast. I'm in the USA so I don't know how fast they ship if you are not in the USA but I think it only took 3 or 4 days (might have even been faster...I don't remember exactly) to get it directly from the company. Check the pricing (including shipping) but don't hesitate ordering directly from the company instead of Amazon or Ebay if the price isn't more.

    I'm pretty sure the epoxy is NOT flexible like silicone would be so might not be what you are looking for.

    If you do get this epoxy, mix it all and don't try to estimate the epoxy/harder mixture. I never tried implanting any of the magnets I coated with this epoxy but mine took a long time to cure because I tried to guess at the ratio. A better option would have been to order a couple small packs of the epoxy and just throw out any that wasn't used at once.

  • @Birdhandz, good advice about mixing it all at once. The durometer (hardness) rating is D86 which is not going to be flexible. However, it should be possible to polish it if you make a mold and have to get rid of any flashing.

  • Thanks! @Birdhandz does it matter which one, or basically any epoxy is considered body friendly?

    @McSTUFF yeaaaahh.. i think test batch at least one or two, then as you said, buff. this would have to be small.

  • Most epoxy is not biosafe.
    Unless it is medical grade epoxy meant for medical applications, don't risk it. The stuff you buy at the hardware store probably isn't going to be healthy. In my first post of this thread, I mentioned the Atom Adhesives version which was tested in vivo by a member of this forum, Benbeezy, I think.

  • https://www.atomadhesives.com/FDA-Grade-Food-Medical-Epoxy-Adhesives/FDA2T-Food-Safe-Medical-Grade-FDA-Adhesive

    Atom makes many different Epoxies.. MANY. so they have a section of "fda" adhesives, as well as potting.. so in this area, there are even still a number of options. If they sell direct, looks great, because they also look very reasonable.

  • I think Benbeezy tested the FDA16 epoxy.
    https://www.atomadhesives.com/index.php?route=product/search&search=fda16
    They have both been tested in vivo so there are options. I believe they sell direct but I know they sell through Amazon and even eBay. If you have a commercial shipping account, they will even send out free samples.

  • yep. i'm glad. this is going to be my source. now i want to find silicone! thanks!

  • @Birdhandz did you ever play with USP6 silicone at all?

  • Exited to see this as it's a material I was unawear of and I'd love to know more about it. I dug back a good bit and didn't see it so I wondered if there was a rundown on implantable materials (fda approved through experimental) as I have had a hard time gathering that info? Lastly, I was a SPFX artist in the 80s and wondered if anyone has done anything with casting acrylic as used for dentures. If acrylic is cool and I have seen pretty old dental pieces that appear to be in great shape given the stress they are put through. It seems like a good possible coating.

  • I bought epoxy directly from Atom Adhesives and the pricing and shipping charges were not too bad. The shipping was real fast too.

    I never tried any silicon and never used the epoxy as an actual implant. I was just testing to see how good I could cover a magnet with it. It worked ok but left some flash around the edges and ended up thicker than I hoped but those problems could probably be fixed with more practice and possibly some kind of mold instead of just painting it on or dipping it into the epoxy.

  • @Daniel Acyrl, or to be more precise PMMA Poly(methyl methacrylate) is rated very bioinert.
    source: ISBN: 978-0-07-149838-8 (chapter biopolymers).
    There are only a few bacteria able to break it down but if your body is full of those you have no reason to worry about PMMA failures anyway/anymore.

    However this does not mean that buying random PMMA or monomers will come in the desired purity to yield a good biocompatible product. Best to go with the highest quality you can get.
    ISO 10993-1 tested for Implant devices for tissue and bone for a contact duration of >30Days is what you really want. Those are very hard to find tho. One compromise is to go with <30Days rated material. I would not recommend to use material intended for <24h contact. FDA class VI is not something you should look for. If your only choice is between class VI and and PMMA from the hobby&crafts store down the street go with class VI but i wouldn't recommend it for long-term use.

  • As an FX artist from way back, with a good bit of mold making under my belt, my idea for making a mold would be to make a mold 1mm or so larger than the object then apply 0.5mm tabs of epoxy to all sides to center the object as perfectly as possible. I would say for a disk magnet make the seam at the very top, not the center because that edge would be at the thickest point for finishing. Aside from the obvious, you want to avoid thin spots in an epoxy mould because the reaction depends on mass, so thick and spots would cure at very diferent rates causing several sorts of problems with something so thin and critical. Hope this can help or caution someone out there.
    Has anyone looked into the materials used for dental fillings? Seems like it could be very strong and stable stuff. Not the amalgam with murcury, obviously.

  • Dental fillings have been experimented with. Cassox was the person who did the most work on this iirc. Results were somewhat okay but there were issues with pitting which would allow bacteria to grow in or something along the lines.

    Another big thing to keep in mind, not only does your coating need to keep the body away from the implant. It also has to work the other way around. Many materials have the property of soaking up water. And especially magnets are very prone to water or moist environments (that's why they get nickel-coated). If moisture gets past the coating and the nickel, the magnet will start to decompose, degrade in performance and probably fail mechanically at some point.

  • Yes. It seems a bit like painted MDF. Any tiny flaw that lets any water in causes expansion that multipies the flaw... And water is drawn in..... and double, double again.........
    Hard can crack and soft can wear. It's like you just can't win with a single soloution. I think Multi layers is going to be the middle way. Structual, like nickle or chrome. Then a softer layer 78D urethane(?) then maybe silicone. Plust the possible layers neede for each to stick to the next. Gets pretty thick fast.

  • my only solution so far is having a rigid titanium shell laser weld around the magnet. It provides a perfectly gas and liquid proof case. It's ductile enough to withstand quite a bit of mechanical load and provides at least some protection in case of failures. With properly done laserwelding the thermal impact for the magnet would be small enough.
    Laserwelding titanium as thing as 0.1 or even 0.05mm is possible, some companies offer such services. I was yet unable to find one willing to do it. Same goes for the price it would cost. But that'd be my personal favorite.

  • I'd go for that if it ever becomes reality. Any ballpark on the price? I'd be okay with $200 if it resolved all my curent concerns

  • as i said. no numbers yet. feel free to ask your local laser-welding expert for prices

  • @Erischilde you may already know this, but I did not see anyone mention it. If you are going to be sanding/buffing any significant amount of epoxy you will want to do it with a mask and goggles on, or outside next to a strong fan. It can be really irritating to your eyes, throat, and lungs if you breath in the dust. I am not sure if it applies to the medical grade epoxy but why risk it, you know? I was working with some marine epoxy during a lamination project and I was not given that advice until I was already in distress.

    Tearless Johnson & Johnson baby shampoo really helped wash out my eyes, and it works great if you are sanding wood too.

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