Can Wing bolts be removed?

After soaking the 16 bolts on dry ice for 6 hours, & putting them in with a soft on the rivet gun, I wondered if you'd ever be able to remove them. When it came time to put the last 4 bolts in... the 1/4" bolts that pick up the nut plates in the spar web, we found out that they were about .032 misaligned. It was a very sickening feeling to say the least! Talked to Ken @ Vans, since the spar carry thru was already pre built, they said this was a 1st! They called back and gave us the bad news, the 804G 1" blocks have a top & bottom and your wings have to come back off. Was a real bummer, but Vans sent us replacement spar bolts all we had to do was get the original bolts back out, drill out the keeper rivets in the blocks and reinstall them the right way! We modified some tooling steel to grab the bolt heads with a slide hammer, and all 16 came out! It was work, but no damage to the holes in the spar! Moral of the story... check for fit on all 20 of them bolts, and never assume that since 16 fit the last 4 are automatic! Big thanks to Vans for a great kit and their support. Here are some pics.1st block drilled off/2.reinstalled with tooling steel to help back rivet the keepers/3.Slide hammer.

N53LW said:

[/URL]

N53LW said:

[/URL]

N53LW said:

[/URL]

Click to expand...

Click to expand...

Click to expand...

please provide a bit more detail on pulling the bolts

1.) how did you get them to move the first bit so you could get the "tool" in place to grab and pull them all the way

2.) few more details on geometry of the "tool"

3.) any mods to the slide hammer?

Been wondering about pulling the bolts out of a 9A,... you can't even get a shot at a couple on the bottom,.. I hope I never have to pull them out.

Removing wing bolts

I have been successful in removing and installing wing bolts by useing a socket wrench and turning like you are unscrewing them for removal and righty tighty for installing. That will usually get you beyond the initial removal and then you have to have a helper apply pressure in the direction of travel.

Bolts

After backing the nuts off, but not removing them, we used a brass hammer to move the bolts back away from the carry thru. We didn't want to take the chance of mushrooming the threads, that would be very bad. Our 1st cut on the tooling steel was to accept the smaller bolts. We also tapped the steel so we could screw it on to the slide hammer. We then opened up the steel to accept the larger bolts. There was enough play left in the steel so we could hold the slide hammer at a slight angle for those bolts at the bottom of the carry thru. I would recommend that if at all possible not to turn the bolts to avoid any scarring of the holes in the spar. Tolerence is so tight that many of the bolts lost some of their plating. Keep some knuckle size band-aids on hand, that blood is corrosive!

I would recommend that if at all possible not to turn the bolts to avoid any scarring of the holes in the spar. Tolerence is so tight that many of the bolts lost some of their plating.

I do not beleive it is possible to avoid losing the plating on the bolts no matter how you install them. I used a big plastic hammer with the shot inside. Oil them up to avoid scarring the holes. Put in freezer overnight.

9A Spar bolts

Following a forced landing had to remove the wings in a paddock. Used a 90? drive air wrench plus home-made claw levers to remove bolts (plus lots of spray lube).

Most bolts backed out at start without pressure on threaded end.

To remove the nuts from the bottom outboard 1/4" bolts you need to remove the brake lines and back out the rear 2 of the 6 small bolts which pass through the fuselage from the gear leg weldment support.

The biggest problem are the nuts on the two 7/16" bottom bolts. It was necessary to trim one side of an 11/16 open-ended spanner to get in behind the weldment and get some sort of marginal grip on the nut so that it would not turn when the bolt was turned. Yes the force necessary to start these bolts was way more than the rated 162 foot/lbs of the air wrench so maybe find a gorilla to help as well. There is no way that I could see of turning the nuts on the bolt due to the weldment.

Bolts look fine but will almost certainly have scratched the inside of the spar holes (hopefully in a fairly minor way).

Rupert Clarke

Process creates the problem

My assessment of why the bolts are so difficult in general is that the holes are drilled with the assembly being bare aluminum. Then, anodizing (in the case of pre-assembled spars) or primer spreads the bars apart a few thousandths of an inch. Four layers of coating to be exact. Don't know what the solution is, but it could surely use one.