You can rivet the anchor nuts to the back of the spar.
See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2015 KR Gathering - McMinnville, OR. September 3 - 6 -- See U There. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il ? MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il ? MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il ? MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il ? MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il ? MVN Best Interior and Panel at 2008 ? KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC -----Original Message----- You're supposed to use stop nuts on the back of the spar but good luck keeping resin out of them.