Can singer oil (sewing machine oil) be used for shapeways puzzles?
The "trick" I use for trying to answer these questions is to search for the material data safety sheet (MSDS) for the product.
So if you Google "Singer Oil MSDS" you'll find a document that says:
Lubricating base oil comprising hydrocarbons of the type alkanes and
cycloalkanes at lower levels of aromatic hydrocarbon
Heavy paraffin hydrocarbon: 65% (p/p);
Naphtenic hydrocarbon: 27% (p/p);
Aromatic hydrocarbon: 8% (p/p);
Sulfur (CAS 7704-34-9): 0.3% (p/p).
If you Google "paraffin hydrocarbon" you'll learn that term is generic for saturated hydrocarbons named Alkanes https://en.wikipedia.org/wiki/Alkane
"Heavy" means it's one of the heavier molecules. Probably octane or heavier.
Googling "Naphtenic hydrocarbon" leads to https://en.wikipedia.org/wiki/Naphtha
Then you can start Googling things like "nylon hydrocarbon solvent resistance" and "pvc hydrocarbon solvent resistance" (the stickers are PVC) and "sticker adhesive hydrocarbon solvent".
- Hydrocarbon solvents are slightly toxic
- Singer oil isn't just highly flammable, it's basically fuel
- The sticker adhesive will dissolve
Also I can tell you from first-hand experience that mineral oil leaches some of the Rit dye from the parts.
So you can use Singer Oil because the nylon would be fine however the stickers and dye and your health would not.