Reading Bonne's brake pad change reminded me of a lovely incident. In my early 30's I was working as a maintenance fitter in a mill, and was working for a "project engineer" with no practical experience and limited theoretical. We had a sales rep in, showing us some 'new' high-temp grease. Inside one of our large and blisteringly hot ovens were conveyor belts running on rollers with bearings needing occasional greasing. The rep opened a side door (about six inches thick with insulation) and on the inside of the door put a blob of ordinary grease, and next to it a blob of his own product. Shut the door, came back 15 minutes later, opened it again. The competitor's grease had run down the inside of the door, but his grease was still firmly 'blobbed' just where he'd put it. Impressive. So impressive that the white-coated project engineer couldn't resist sticking his finger in it. Fried his finger end. He'd assumed it was somehow resistant to the heat, rather than resistant to melting.