Paint jar caps that are stuck or tightly sealed are a problem most modelers’ experience.
In the spray booth at Model Railroader, we use an Oxo Good Grips jar opener (no. 21191) to open stubborn paint bottle caps. These are sold at most major discount stores and specialty cooking shops. Just place the cap into the bottom of the opener and rotate counterclockwise, 1. I’ve found it best to apply light to moderate pressure as the metal teeth can rip the cap.
Another kitchen gadget that works well is a rubber jar grabber, 2. These are sold at the same places as the Oxo tool, or you can get them for free at county fairs or home shows. (Just look around the exhibition hall – that’s where I found mine.) The grabber is fairly reliable, and it saves a lot of wear and tear on your hands.
A third option is a strap wrench. I found mine in the “As seen on TV” section of a local drug store several years ago, and I’ve seen similar products at hardware stores and auto supply centers. The wrench features a plastic handle with a rubber strap. After fitting the strap around the lid, twist the wrench counterclockwise until the cap pops off, 3.
The final fix is warm tap water. That’s right. If you use acrylic paints, hold the bottle upside down and dunk the cap in warm water, 4. Let the bottle stand on end for 5 to 10 minutes, and twist the cap. You may want to use the rubberized jar grabber or strap wrench in conjunction with this technique.
If you do any painting, keep these techniques in mind. Your wrists and hands will thank you, and you’ll have more time to spend modeling.