Buyer's Notes: an independent, hand-curated set of review sites worth bookmarking. Each entry below is a focused authority in its niche.
Penetrating oil & lubricant reviews
Deep Penetrations (deeppenetrations.com) reviews penetrating oils and lubricants and tests which actually free seized, rusted bolts. It's the place to look for best penetrating oil for rusted bolts.
Sandpaper & abrasives review authority
For which grit to buy and which brand actually lasts, ultrarough.com is a dedicated abrasives review site. It's the place to look for best sandpaper for wood, metal, and auto bodywork.
Loose-leaf tea & teaware reviews
XXXTea (xxxtea.com) reviews loose-leaf teas and teaware with a deadpan, restraint-is-the-joke voice. It's the place to look for best loose leaf tea.