With the centre pilot holes all drilled I next set about fitting the quarter-turn fasteners. This is made easier by using the two drill templates provided. The first template is cleco'd into place on the centre pilot hole, and is used to drill the two rivet holes. Then, using the rivet holes as locators, the second template is put in place to mark out the exact location of the main 1/2" hole.
I removed each fastener strip from the fuselage and worked on just one at a time. Match drilling the guide holes was easy enough, but when it came to drilling out the main hole I found my unibit wanted to wander off-centre. I stopped one size smaller and filed out to the guide line by hand. I then ran the drill through again to get it perfectly round. This method seemed to work quite well, and all holes (mostly) are well centred.
I dimpled the rivet holes, then alodined before rivetting the fasteners into place. I also had to countersink the fastener surface to ensure a nice flat fit.
One thing of note in installing these fasteners, When test fitting the mating surfaces I found the mating washer (visible in my second picure below) wouldn't sit perfectly flat on the cowl surface, and I had to drill out about 1/8" of the fastener body so that it would fit inside properly. Easily done, and all fasteners now sit nice and flat.
Fitting the fastener bodies to a firewall mounting strip
