Even the strongest glues can’t handle some materials, including rubber, galvanized metal, and brick. Things you’d think would be glueable — but aren’t.

High Heels: They may look like delicate creatures, but they have to withstand 2,000 pounds per square inch of pressure (the impact of a 125-pound woman in stiletto heels). For anything but a simple flat heel, see your cobbler.

Eyeglass Frames: Because they’re fragile and endure constant wear and tear, “there are no glues strong enough” to repair them, says Lisa Conti, manager of the retailer and repair specialist My Optics, in New York City. The pros order new parts or solder wire frames back together.

Hoses: Lorrie Lipe of hose maker Fiskars says bonding agents in glue don’t adhere to PVC material: “It would leave a weak point that would burst as soon as water pressure was applied.”