prewar rib rivets

[Dot_AK]

What size rivets are used in the pre-war built up ribs?

Thank you!

[astjp2]

Re: prewar rib rivets

I used an 470ad-3's and the length was based on how many layers I had to rivet together...Tim

[Larry Lyons]

Re: prewar rib rivets

Great timing, as just last night we were talking about rivets on these old ribs. My pre-war built up ribs, of course, have steel rivets. When repairing do I have to use steel or is is an aluminum rivet acceptable.
Larry

[VictorBravo]

Re: prewar rib rivets

I'd sure use the new aluminum rivets regardless. You can set up a hand squeezer in a bench vise in such a way as to do them just as fast as the other ones. One of those RV homebuilder C-frame dimpling/riveting tools would be really great for the job too. Either alum. or steel rivet is probably over-strength for the loads, and the thin material of the ribs. But drilling out an aluminum rivet is less risky for damaging the ribs. Dis-similar metals are not really supposed to be in contact with each other... but to be honest most pre-war ribs have been together for 66 years and have not corroded.

Bottom line is you could use either one with little fear of doing the wrong thing.

Original or not, I don't think anyone at the FAA would disagree with the choice of AN470 aluminum rivets... because I don't think there are any FAA certified steel hollow rivets made anymore for you to use even if you wanted to. The 43.13 book has drawings showing truss ribs being repaired with AN rivets in several places. Use the smaller AN470-3 size as previously mentioned.

On the other hand, if you used non-certified commercial steel rivets (which of course is what T-craft used), you could say to the FAA "I used the same thing the airplane was built and FAA certified with !".