I was dead wrong about torque wrenches on composite panels

Been doing sheet metal work for 7 years at a regional line in Spokane. Always figured you could just snug those composite panels by feel like the old aluminum ones. Then last month an A&P showed me the actual torque spec on a CRJ door panel was 12 inch-pounds. I overtorqued a test piece by about 40 and got visible crazing around the fastener holes. Now I check the book every time even on stuff that seems simple. Anyone else have a torque surprise that changed how you work?

2 comments

2 Comments

davis.linda1d ago

You bet. I used to think getting a torque wrench out for something like a composite panel was just wasting time, figured the feel was all you needed. Then I saw what happens when you get it wrong on a composite cargo door, same kind of crazing you're talking about. Made me realize that feel is great for aluminum where it's more forgiving but those composites don't bend or give like metal does, they just crack. Now I treat every fastener on a composite like it's made of glass and check that spec even if I'm in a hurry.

angelas781d ago

Watching @davis.linda torque a composite taught me more than any manual ever did.