Over the last two weeks I’ve been match-drilling the firewall components and fabricating a couple of additional brackets that bridge the firewall and fuselage floor stiffeners. There isn’t a lot of margin for error on these, and it’s easy to wind up with insufficient edge distance when match-drilling them to the existing stiffeners and gussets you see in the picture. I wasn’t happy with the first attempt, so I fabricated and re-drilled another pair of brackets – they turned out much better.

One other bit of fun is fitting this small doubler that reinforces brake line penetrations through the firewall.

Match-drilling the plate isn’t the problem, but drilling through stainless steel is. Follow Van’s guidance in the plans book and you’ll be fine, j ust remember to use slow drill speeds, and use boelube or some other cutting fluid when you drill. Also, use a Unibit for any hole larger than #30 – works like a champ and is less likely to leave burrs on the stainless. I also made sure to use the doubler as a backing plate, drilling through the stainless first and then the doubler – that also helped avoid burrs.