Bolt hole tightness?

[John Sowles]

Built new spars. Drilled holes on drill press using old spar as template. Most all bolts fit nice and snug, tapping in lightly. A few holes, however, are quite tight, requiring more than a light tap, although the bolt does pass through. Is there some advice as to how one knows if the fit is too tight? Ie. in danger of splitting the spar. They may be off center just a hair. At what point does one become concerned?

[N96337]

Re: Bolt hole tightness?

I like mine to be a slight press fit... I have to press it through with my thumb. I always figured if it went too easy, it's going to shock load things from being too loose and able to move, albeit very slightly. Did you put the phenolic bushings in? If so, you might be able to ream the bushing with an adjustable reamer, as long as the hole is located properly.

John

[John Sowles]

Re: Bolt hole tightness?

I have both phenolic bushings (on front spar) and not (on rear). It's a BC65. Most of my holes are as you describe with snug thumb pressure. But on one butt fitting and strut attach point, one bolt is very tight. Off center. I'm tempted to run a fine file through and recoat hole with epoxy to take up the slack on the off side. Maybe I'm making too much of this and if so, folks can tell me. I do want it safe.