Al Aitken

Sanded number 4 frame for perfect fit with main spar.

Varnished inside of number 4 frame prior to gluing.

Scuff sanded main spar in area of number 4 frame prior to gluing.

Aerolite applied to main spar to glue number 4 frame.

Hardener applied to number 4 frame for gluing to main spar.