More Center Section Bulkhead questions...

In order to match drill all of the holes in the center section parts, the instructions indicate that I should insert two close tolerance bolts and cleco the parts together. Inserting the bolts insures accurate alignment.

So I opened the wing bolt bag and inserted two bolts. As you can see in the pic below, only the threaded portion of the bolts go into the holes.

In order to get the bolt in, it looks like I would have to tap it with a hammer. If I do this, I would bet that it would be a B*&^CH to get them back out!

So, do I have to insert the bolts all the way? Suggestions? Thank you-I really don't want to screw up these gold parts since they are all match drilled and built at the factory. Replacing them would be slightly expensive!

They are close tolerance bolts, meaning they will be a snug fit no matter what. I found it helpful to wipe down the bolts and holes with a little solvent, then put a few drops of Boelube on the bolt shanks. In the end, though, you're just using them to accurately line up the F-704C and D parts to the bulkhead. The bolts don't need to be all the way in, but they should be in past the threads at least. I was able to get mine in with a little patience, Boelube and twisting. I did have to give a few gentle taps with a plastic dead-blow hammer to unstick them once or twice during the F-704 assembly process.

Bolt Holes

I suspect the holes in the sheet metal former are not in precise alignment with the holes in the carry thru structure. Do the bolts go in the carry thru structure without the formers installed?

I think I had to tweak the holes in the former on my -8 fuse to prevent binding of the bolts.

No the bolts do not go through the bulkhead holes at all. They might if I lube them and tap them with a rubber hammer as another suggested.

Or, maybe I can try the ol' freeze the bolts and heat the bulkhead trick

Yup, that is what I would try; freeze the bolts and leave the structure out in the sun for a while.

If you are just fitting things up use some hardware grade bolts but grind the threads off of them so you do not damage the inside of the center section. Do a search and you should find plenty of info on this.

Joe Parish said:

If you are just fitting things up use some hardware grade bolts but grind the threads off of them so you do not damage the inside of the center section. Do a search and you should find plenty of info on this.

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What Joe said...
Use some hardware store bolts and grind the threads down on them a bit to make alignment pins. Save the NAS Bolts for the Final installation.

aeroaddict said:

Yup, that is what I would try; freeze the bolts and leave the structure out in the sun for a while.

Click to expand...

Not a good idea for temporary installations - it would tend to make them permanent...

I just went through this exercise ... some holes are a little tight, some are a little looser. A few taps with the dead-blow hammer did the trick. Some of the cadmium coating came off the bolt in the process. I scrubbed them down with a maroon scotch brite pad and then boe-lube'ed them to get them in. A tap on the flat part of the shaft knocked them out easily (I used the handle from the screwdriver part of my socket set ... it had a nice, smooth end to contact with the flat end of the bolt. Many folks say that they use their rivet gun to drive these babies home for the final assembly. A little friction now seem expected.