Scarfing turns a thin butt joint into a long, gently angled bond with a large area and little stress concentration, keeping the joint flush with the surface. Slopes of 1:20 to 1:50 are common in composite skin repair, while wood scarfs usually run 1:8 to 1:12. Scarf joints give some of the highest efficiencies of any bonded joint but take careful machining and fit-up.
Repair calls for a 30 to 1 scarf joint on the skin, so that's a long taper, take your time with the grinder.
Also heard as
- scarf
- scarf repair
Related terms
Lap joint
A bonded joint where two parts overlap face to face, loading the adhesive mainly in shear.
Butt joint
A joint where two parts are bonded end to end, with only the small end area carrying the load.
Bondline
The layer of adhesive between two bonded parts, and in shop talk the thickness of that layer.
Peel stress
Tension pulling one adherend away from the other at the edge of a bond, concentrated along a thin line.