Hacker News Reader

Comment by semi-extrinsic | Hacker News Reader

FWIW, people have been researching how to recycle thermoset epoxy for at least a decade. Here is one example of an open access paper:

https://pubs.acs.org/doi/full/10.1021/acsapm.1c00896

From my reading of the press release, the novelty in this work is that they've found a process that works with "ordinary" chemicals, temperatures and pressures, so it can be scaled up economically.

I say "ordinary", because it might very well be working with mildly toxic chemicals at 80°C and 7 bar pressure or whatnot, so far outside the range of (at least economic) feasibility in the home lab.

View on HN

That should not worry anybody though, the fabrication process is at least as dangerous. I've worked a lot with various kinds of epoxy (and yes, also to make windmill blades) and reading the MSDS on your typical resin is enough to make you wonder if you even want to use this stuff at all.

For the curious readers: https://jacquesmattheij.com/how-to-build-a-windmill/

MSDS: Material Safety Data Sheet

Looking in my workshop, nearly 100% of the "stuff in solution" there have solvents you do not want to breath. Then you do a bit of skiing and you see the composition of the waxes. You do a bit of woodworking and home improvement and you look at the composition of the glues. They are full of deadly compounds. So yes, we should not worry but still handle with care.

My simple advice: if you see on the product that it should be used in a well ventilated place, do it!

Excellent timing for my certificate to expire :) Fixed.

That is very true. I'm surprised many people seem not to care.

I use mostly safer compounds in my workshop (platinum-cure silicones, polyurethane resins, and occasionally good grade epoxy), but I still put on a proper mask, glasses, and gloves. Especially when working with my daughter. Those half-mask respirators are surprisingly comfortable (I found them easier to wear than N95/FFP2 masks).

The smell of the stuff you get from the hardware store ought to be warning enough that it shouldn't be used carelessly.

The main problem is that over time you become more and more sensitive to it. So even if initially you have no response don't be surprised if after some time of using it regularly you have really bad allergic reactions to even mild exposure.

Yup. Anecdotal story, a friend of my father was making a boat for himself and he became so sensitized to epoxy that he had to stop working on it and hire somebody else to finish it for him.

(For boatbuilding, the usual choice is polyester resin rather than epoxy, which is nasty in other ways. You don't wanna be inhaling those styrene vapors all day long.)

If you haven't had the misfortune of discovering this yourself, polyester resin is EVEN WORSE smelling than epoxy resin.

I got a kit with some fiberglass to fix a cracked bumper on a car. Don't want to do that ever again.

I'm no professional boatbuilder, but I've been helping out friends and family with DIY glassfiber boat repairs and improvements. So yes, I have experience of both polyester resin and epoxy. They have their own issues, as discussed in this thread.

Epoxy is highly allergenic (or whatever the word is), so you should be pretty careful about using nitrile gloves or similar when working with it. Personally I don't find the smell particularly bad, and it's not very strong, at least compared to polyester resin.

Polyester, yes it smells bad, and as I mentioned in my parent comment that's styrene vapors you're inhaling, which is a known carcinogen. If I were to do some bigger job with polyester, I'd definitely want some pretty hefty breathing filter. But for the occasional one-off thing, particularly if you can do it outdoors, meh..

Mostly a gut feeling: Anything someone can grow sensitive to, such as this or smoke or anything, should at least be very carefully examined as a cause of harm generally.

That's partly about concentration. I've heard of people becoming allergic to lavender, which is normally pretty unlikely, because they imprudently used the concentrated oil on their skin.

>>Anything someone can grow sensitive to

AFAIK most allergies/hypersensitives are for harmless things; animals, pollen, and different types of food. So basing what we grow sensitive to might not be the best test to see if a product can cause harm

If you get resin on your skin and it starts curing under your skin your immune system will have to get rid of the stuff under your skin and because it is so difficult to get rid of cured resins your immune response will be incredibly sensitive.

Reply on news.ycombinator.com