This one sounds pretty simple. I'd like to print myself and a friend some cups to drink from using my Anycubic Photon. Issue is the resin is toxic, so I need a coating that will allow it to be safe to drink from. All I can seem to find is stuff that's either not safe for food or is meant for wood, and I'm getting irritated. Thank you for your help.
Perhaps consider a different material. Mineral water bottles are made from PET, so are many food trays. Switch to PETG. Worth double checking the migration data, but they go in microwaves and in ovens upto 220’C, so coffee is no prob.
You can use Urushi, it is the resin of a tree that is used since a few thousands of years to make chinese lacquerware. It is a bit tricky to cure, but it is food safe and can hold high temperatures.
I wouldn't do it, but not because resin is popularly claimed to be toxic. Women have been painting their nails with UV resins for many decades and I doubt anyone suffered as much as an allergic reaction.
I'd advise against using resin for anything food related because it breaks just like glass. Shards fly across the room. If one lands in someone's soup, and they swallow it, the hospital X-ray won't show it...
My very last project involving resin and food was a meatball making tool. At one point I noticed a triangular fragment of one cup had broken off. I looked at the dozens of little meatballs in the bowl, wondering which one had it... Everything went in the trash.
Another option may be to find a food safe cup and then design your cup around it. I did this for a project back in March using small glass cups.
Caveat: I wanted to get a press fit between my print and the cup and couldn't because my cups got slightly wider from bottom to top (truncated cone) so any force that might have caused friction pushed them out of the print as well
Apology: I can't find any reference to the specific cups that I used
There ya go
My thoughts exactly.