I'm working on a plane that only has about 15% of its original japanning intact. I'm looking for a solvent that can help loosen the remaining finish without causing damage to the cast iron through excessive scrubbing. Since turpentine was originally used for this purpose, I'm wondering if it would be effective now or if I should consider a different approach, especially since the asphaltum and boiled linseed oil (BLO) have probably polymerized over time.
4 Answers
If you're considering alternatives to harsh chemicals, heat treatment works well too. Like mentioned earlier, getting it up to about 400°F can really help soften the finish for easier removal without harming the metal.
Bead blasting is often recommended for removing japanning. It's effective, but I understand if you don't have access to that equipment. If you don't, you might want to look into heat as an option. Heating the finish to around 400°F can soften it without damaging the cast iron. Just make sure to monitor the process closely!
You should know that asphaltum japanning is a varnish, which makes it trickier to remove than an evaporative finish. While solvents like alcohol and acetone work on those, they won’t do much for varnish. In fact, you'll find that older paint strippers with methylene chloride were incredibly effective on varnish but might not be safe. If you're looking for a more modern approach, orange solvent or limonene is much stronger than turpentine and could help weaken the varnish over time.
I really appreciate the detailed explanation! I had no idea it was a varnish, but your insights definitely cleared things up.
Citristrip could also be worth a try if you're looking for a more environmentally friendly option. It’s known for being effective on various finishes, including varnish. Just remember to follow all safety guidelines since you'll be working with strong solvents!
Thanks for the heads-up! I'll definitely consider using heat if I can manage it.