When the fog finally returned in year four, Mark didn’t sigh. He simply ordered a new IGU, removed the sash, and replaced the glass unit properly—this time with confidence, because he knew exactly how the enemy worked.

Mark knew the fix was temporary. Drilling and drying doesn’t restore the original argon gas—only dry air. The thermal efficiency dropped from R-5 to R-1. And the seal might fail again in 1–3 years. But for $18 in materials and a weekend’s work, he bought three more years of clarity.

The window was clear. Not just clear— perfect . Mark stood with a cup of coffee, watching the oak tree shed its autumn leaves. Leah hugged him from behind. “You fixed it,” she whispered.

Once he was sure no moisture remained (tested by taping a clear bag over the holes—no condensation formed), he injected the low-viscosity silicone into both holes until a tiny bead squeezed out. He then pressed clear mylar tape over each hole. After 24 hours, he shaved the dried silicone flush with a razor blade.

Mark rigged a small aquarium air pump to blow gentle, dry air into one hole. For 48 hours, the window “breathed.” The fog disappeared. The glass became perfectly transparent for the first time in years.