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Removing RV-9 spar bolts

A

alpinelakespilot2000

Well Known Member
Some of you may remember that back in January my hangar mate ran into my starboard wing with her truck. This necessitates me pulling the wing to replace the outboard wing skins and ribs. It should be a relatively straightforward repair assuming the wing comes off *easily* enough. That's a BIG assumption though! :rolleyes:

Any tips or do's/don'ts for getting the 8 close tolerance spar bolts out? The good news is that it's a taildragger, so no gear mount in the way. I've read a few old threads about air ratchets, impact wrenches, rivet guns to push them out from the front, using drift pins, special purpose-built pry tools I don't have, etc. Any particular order I should try to pull them—bottom/top, big/small? Would love to hear from anyone who's done it and can report that it wasn't too hard. 😁

Seriously, though, I definitely don't want to risk damaging the spar or spar box so I'm just double (or triple) checking that no one else has some good tips.

Thanks!
 
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Nah, not too hard. Just take it slowly and cautiously.
-Make a punches for each size bolt out of regular tolerance hardware bolts. Grind away most of the threads and make a blunt tip. You will need four of the largest size to use as temporary pins if the wing will be reattached temporarily during the project. A hammer and/or rivet gun and those punches will do the job.
-support the opposite wing.
-don’t forget to remove all the screws from the lower fuselage overlap skin
-triple check that everything else is disconnected…
-support the wing (I used sawhorses and old sofa cushions). Use a couple of helpers to wiggle slightly up and down while pulling out. Should slide right out.
-use care to not lift the outboard wing too high and lever down on the inside belly skin with the lower corner of the spar end.
-when reattaching make sure the lower fuselage overlap skin is not impinged and gets routed under the wing.
-it goes without saying to drain the fuel and remove the flap and aileron first…
Good luck!!
 
Have you put a wrench on the bolts yet? (Assuming you loosened the nuts first). Do the bolts turn?
If so, use an air ratchet on the bolt head & tap the threaded end at same time.
Remove the small bolts first, than the big ones last. Follow all the suggestions about supporting the wing panel during the process.
Edit- Plan to use new bolts when reinstalling.
Good luck
 
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A great trick to protect the spar & everything is to use a short piece of fuel line hose, maybe 5/16 or 3/8 to couple the bare bolt threads to a punch you're about to use to push the bolt out with... it keeps everything aligned while your busy with a hammer or rivet gun. Push the hose over the bare exposed threads of the installed bolt - then push the punch into the other end of the hose.... tap tap tap without worry.
 
What Dan ^ said.
I had to remove one. Forgot the dang washer! Thankfully it wasn't all the way and it came out.

If you can access the thread side, run a nut on a little ways and tap to get it moving then remove the nut. Once the head is clear, slip a flat piece of slotted aluminum between to protect the spar. Use whatever to pry while rotating with a wrench or socket. Something like two screwdrivers works best to apply even pressure.
If you can't access the nut side, grab the head with a vice grip really tight. Needless to say this bolt is scrap. Slip something in place to protect the spar and rotate back and forth while prying on the vice grip till you can get in there. Wood shims are handy as the gap increases to help pry them out.

Someone should make a spar bolt probably slotted to fit the bolt shank. Hint, hint.
 
I'm a fan of using short pieces of Delrin rod, 1 size under bolt size, to assist in pushing bolt out of bore - several short pieces can be coupled together inside a fuel tube to work in a confined space too, I do not like twisting a thread inside a bore. I'm also not a fan of levering a bolt head to pry it out. Yes - never reuse a close tolerance bolt that had to be tapped into place.
 
AZSteve053 said:
I'm a fan of using short pieces of Delrin rod, 1 size under bolt size, to assist in pushing bolt out of bore - several short pieces can be coupled together inside a fuel tube to work in a confined space too, I do not like twisting a thread inside a bore. I'm also not a fan of levering a bolt head to pry it out. Yes - never reuse a close tolerance bolt that had to be tapped into place.
Click to expand...
I agree. If you can access to drive it. That's the best way.
 
Thanks all for the good suggestions! Couple follow-ups:

1. For those who used a rivet gun to push the bolts out, what kind of set did you use? Flat/flush set? Universal head set? Regardless, I'm guessing the set should be considered sacrificial?

2. I'm *assuming* the first couple of the eight bolts will come out "relatively" easy since the other 6-7 will be holding the everything in perfect alignment. Then the following bolts will required more wiggling of the wing. Good or bad assumption?

Thanks again!
 
It's not rocket surgery, so don't get too freaked out about it. There are plenty of good suggestions above. It may help to get the plane in its level flight attitude before you start. Get all of the tools you may possibly need (and then some more), including supports, padding, etc., then just go for it. And have plenty of help on standby for when you need that fifth, sixth, or seventh hand.

I found an old office chair on wheels with the back removed came in very handy to rest the weight of the wing near the fuselage. The pneumatic height lever can be adjusted to give more or less support as needed.
 
A relatively short HW store bolt ground to a nicely rounded tapered tip is great to start with, insert it into rubber hose with head exposed, use a flush set with a good but thin (1/4") rubber sanding pad between set & bolt to protect the set... when partway out switch to a longer HW store bold similarly prepped or a Delrin rod.
I've never injured a rivet gun set in this manner.
after the 1st several bolts are out it REALLY helps to have a helper to hold/wiggle wing thus relieving shear stresses on bolts... Easy Peasy so to speak
 
Actually was way easier than I expected getting all 8 bolts out. Only two challenging issues: (1) knocking out the outboard most 1/4" bolts just because the side skin and stiffeners were in the way--using a rivet gun would have helped address this issue, though I made a hammer work. (2) it was actually harder later when punching out the last couple drift pins, and that's actually the only thing that required a partner to hold/wiggle the wing. Though I won't do it again just for fun, if there were another major repair that necessitated pulling the wing, or if painting would be much easier with the wings off, I would consider it to be in the realm of acceptable possibility! : )

Thanks for everyone's help! Now its on to drilling out a few hundred skin rivets and hoping Van's CNC machine used the exact same settings/measurements for the outboard skins that was used in 2005 when I bought the wing kit!
 
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