Tonight I drilled holes in the firewall for brake lines, and touched up the paint on the inside of the firewall.
I made a template to help locate and then check the position of the two holes in the firewall where the brake lines will pass through. I center punched the holes, then started drilling with a 1/16th cobalt bit, then worked up to 1/4 inch, then switched to a step drill to get to the final 13/16 size hole. With the holes drilled, I used the flange fitting to locate 6 additional holes around each 13/16 hole, where 3-3.5 rivets will hold the flange fitting in place.
I used some acetone to clean paint off the stainless firewall on the inside, then carefully taped the areas where I want paint (on the aluminum), then turned the fuselage inside down and brushed some paint onto the aluminum angle on the firewall.
Now I’m about ready to proseal the 4 firewall fittings that need it; two brake line flange fittings, the brake reservoir nipple, and the fuel line. once that’s done I should be able to wrap up this chapter with a few more evening’s work.
