When I built my spars and center bulkhead, I got a little bit of primer overspray in the center bolt holes. Here we are years later and getting the bolts in with that dried primer in there is a no-go. Lucky for me there's an industrial hardware supply near me. They sell a 3/8 inch diameter stainless steel wire brush that I was able to chuck in my electric drill. A little acetone and a couple of spins and things are like new. These brushes come in lots of sizes and are actually called valve guide brushes. They are also available in steel and brass, but the stainless is probably the best choice to avoid driving little bits of steel into the aluminum, which could cause corrosion.
Steve Zicree
RV4 Old-School Sloooow Build
Steve Zicree
RV4 Old-School Sloooow Build
