I was somewhat disappointed when I learned this is not, in fact, done with a gold-based solder.
Repairing my mug with Kintsugi
81–86 of 86 posts
Re: Repairing my mug with Kintsugi
#82> These days, some hobbyists opt for modern epoxy instead of the traditional and expensive Urushi lacquer. Epoxy probably yields a more robust bond and certainly allows for quicker repairs, but I question its safety for food-related use, especially at the temperatures found in a steaming cup of coffee. People opt for epoxy because Urushi lacquer is traditionally made from poison oak sap and is a potent skin irritant…
I've never trusted that food safe epoxy actually is. I'm afraid that lobbyists have interfered, or its a situation where "there's no evidence that it's dangerous but there's not really evidence that it's safe", or the studies are funded by manufacturers, or there's something like manufactures pulled with BPA where they just switch to something functionally equivalent to a potentially dangerous chemical. Is there any…
It's confusing. There's food grade and food safe. There's some more information here, and it's still confusing.
https://www.wisebond.com/blogs/epoxy-blog/is-epoxy-food-safe
Re: Repairing my mug with Kintsugi
#83> These days, some hobbyists opt for modern epoxy instead of the traditional and expensive Urushi lacquer. Epoxy probably yields a more robust bond and certainly allows for quicker repairs, but I question its safety for food-related use, especially at the temperatures found in a steaming cup of coffee. People opt for epoxy because Urushi lacquer is traditionally made from poison oak sap and is a potent skin irritant…
I spent a few years messing with different approaches with epoxy but I never found anything that could replace urushi. It's really hard to get foodsafe epoxy to cure as hard as urushi, though I did eventually get one I was happy with. But the wheat flour in the traditional material pulls the shards together as it dries, and gives just an incredibly tight and strong bond that can really hold up to actual use of the re…
> Cashew lacquer
Hum... That can't be a coincidence. Both plants are on the same family. Let me check...
Yup, Cashew produces urushiol also. Unlike pistachos, cashew shells must be removed before selling the fruits for this reason.
So cashew plants can trigger skin allergies. Is a common family thing. Harvesting this things burn the workers hands. My bet is that would be also unsafe for people allergic to poison ivy.
Re: Repairing my mug with Kintsugi
#84Earlier quoted context omitted.
I'm not a doctor/chemist, but as far as I understand, the polymerization of urushiol renders it hard and inert. Your thread discusses contact with raw urushiol as found in poison ivy, cashew sap (and apparently mangos) which is indeed known to cause allergic rashes in most humans. I'm not saying that kintsugi is definitely food-safe, but it's an important distinction. Side-note: I did get some raw urushi on my finger…
> Side-note: I did get some raw urushi on my fingers while working on this project, but nothing happened. Perhaps I'm immune. Might also be enough mechanical rubbing on fingertips during normal use that it mostly scrubs off. Whenever I feel it coming on from Urushi or accidentally touching poison ivy in nature, I rub it with water and course sand/dirt which seems to get rid of the urushiol.
Tecnu seems to help quite a bit in my experience.
Re: Repairing my mug with Kintsugi
#85[flagged]
Re: Repairing my mug with Kintsugi
#86ITS POISON IVY! Do not breath in that stuff! I ended up the hospital with my face all bloated. No kidding. Japanese harvest from the urushi tree containing urison the irritant in poison ivy! I think they get off on shipping this stuff to American's laughing at them.