Wing and tail mounting hardware questions

[beeryboats]

My A&P friend noticed surface corrosion on the wing and tail mounting hardware on his first quick walkaround when I first bought my Mod IV. So I've got hardware to change! As I'm not the original builder I have none of the original plans or parts list. I'm assuming the wing strut bolts, top and bottom, are close tolerance. And at a casual glance, the upper strut bolt and nut look impossible to change as they are half hidden in the wing covering. And then I start wondering about the proper torque. And then that leads me to wonder about the mounting hardware at the leading edge. It came with castle nuts and safety pins. Is that normal?
Thanks,
Jay

[mr bill]

I used self locking nuts, but the bolts are loaded in double shear, so the joints do not need alot of clamping force.

[HighWing]

Agree with mr bill. Bolts are AN bolts. I routinely purchase from Aircraft Spruce. On the wing struts with one end of the bolt buried in fabric, I took a wrench and ground it down so it could be pushed under the fabric to minimize pressure on the fabric. A "T" made of 2X2s to support the wing during replacement.

[beeryboats]

I used self locking nuts, but the bolts are loaded in double shear, so the joints do not need alot of clamping force.

Are you referring to the leading edge bolts?
jay

[beeryboats]

Agree with mr bill. Bolts are AN bolts. I routinely purchase from Aircraft Spruce. On the wing struts with one end of the bolt buried in fabric, I took a wrench and ground it down so it could be pushed under the fabric to minimize pressure on the fabric. A "T" made of 2X2s to support the wing during replacement.

Any idea what torque they call for?
thx,
jay

[jiott]

All this is in the assembly manual.

[jiott]

As just a general friendly piece of advice, I would strongly encourage anyone who buys a project Kitfox, whether its major or minor repairs, to immediately buy the appropriate assembly manual from Kitfox. Spend the $50 or whatever to get the authentic information; after all you are going to be spending probably thousands of dollars to get it running. Are you going to trust some yahoo like me to give you a torque value or a hardware spec on an item that your life may very well depend on? I have seen much bogus information go out on this forum over the years; 99.5% of it is good info but get the proper bible to be sure.

[mr bill]

It really is a good investment.

[beeryboats]

Of course you are correct Jim. I pulled the build manual out and started thumbing through the pages. It's not a very easy read to find the info, but I did find some of the info I was looking for. I did find the upper wing strut attaching hardware, but no info on how to torque a half hidden nut. Hmm. I'll keep looking but I don't have and extended crows foot. I did find the tail info in the fuselage section, one page, and it looks like the hiem joint on the V strut support is a female thread. Laying under the tail I thought it was male. Hmm, may need new V struts. Yikes! Wife is going to be upset!

P.S. Have they improved the manual from 25 years ago?

[jiott]

Yes, I hear that the manual keeps improving over the years. I can only speak to the SS7 manual which in my opinion is excellent. A torque value for nearly every bolt is given; however, for the few that are not individually called out, the manual says to use the standard torque tables given, I believe, in the "Builder's Tips" section. Its good that you are trying to find the correct info. I know a guy who was just winging it and actually broke a bolt from overtorque in a critical area. Its a good thing the bolt actually broke so he could replace it, rather than an invisible overstress that would break later.

[beeryboats]

I walked out to the barn and measured all the hardware and ordered from Spruce. What I found comparing what I measured and what the book calls out is strange. If the book called for AN3-4A, I measured -7A. They were all that way, slightly longer. I may to go back out to take another look to see if the builder doubled up on washers. I was having a hard time in a dark barn with reading glasses trying to fall off my face with a ruler in one hand and a flashlight in the other. All I was interested in was grip length, didn't pay too much attention to the washers.
Jay

[jmodguy]

Jay
I know what you mean about the hard times!

[PapuaPilot]

All I was interested in was grip length, didn't pay too much attention to the washers.
Jay

That would be a lot of washers. If you use a bolt that is one grip length longer it takes 2 normal washers to fill the gap.

[beeryboats]

That would be a lot of washers. If you use a bolt that is one grip length longer it takes 2 normal washers to fill the gap.

I know, and it didn't look like there was a stack of washers on every bolt. I'm hoping I get the chance to work on her this weekend. I need to move the Jeep and unfold the wings so I can get a better look.