BULKHEADS, STRINGERS, NAILS & GLUE

airpix · Post by **airpix** » Sun Oct 28, 2007 11:23

I am assembling the wood parts on my chief and notice the original had small nails holding the stringers to the bulkheads. My thinking is that a little epoxy adhesive would be better for this. Any thoughts out there?
Looks like most of the wood is original on this ship, so I am putting in all new.

Also, I found numerous aluminum U-channels bolted vertically to each bulkhead, evidently to keep them straight. Is this common? Doesn't look original, seems like a good idea though.

There were some aluminum brackets attached to the stringers and clamped to the fuselage tubes, presumably to help keep the shape of the wood. Definately not original.

This aircraft is on floats, so perhaps a previous owner thought the additional parts might make it less likely to break something when climbing around on the tails of the floats.

Any close up photos out there would be appreciated, along with any assemby tips.

Thanks

Charlie Lester

Nathan K. Hammond · Post by **Nathan K. Hammond** » Mon Oct 29, 2007 01:59

Hi Charlie

Nails are used, because once fabric is on and shrunk, the stringers are held in place. If you use glue/epoxy (which is fine) just remember, someday you'll be recovering the airplane and will want to pull the stringers and bulk heads. So only use enough to do the job.

In the quest for saving weight by mechanics/owners, sometimes the bulkheads are made of 3-ply 1/32" and don't have the strength. So the guy doing the rebuild desides to add a 'stiffener' and the end result is the same weight.

Sounds like you're having fun.

nkh

airpix · Post by **airpix** » Wed Oct 31, 2007 18:13

Thanks for the info Nathan, and especially the photos....I think I have some others from another post that were very helpful too.

I will go with just a drop of epoxy on each joint to avoid spliting or cracking the wood with nails

Looking forward to another weekend in the shop.

Regards, Charlie

Nathan K. Hammond · Post by **Nathan K. Hammond** » Wed Oct 31, 2007 22:26

Thats a good idea, then the next guy to rebuild it won't curse your name as he's pulling stringers.

nkh

shorty · Post by **shorty** » Sat Nov 03, 2007 19:50

Our stringers were held in place with safety wire. oops, it's a pre-war

Post by **joea** » Sun Nov 04, 2007 02:41

shorty wrote:Our stringers were held in place with safety wire. oops, it's a pre-war

Have seen this on several airplanes and feel that its done to save weight. If it worked for the factory back then, should work now!

David Johnson · Post by **David Johnson** » Sun Nov 18, 2007 06:41

Shorty, you may not be far off. I have several Citabria's apart now, they used safety wire! Not a bad idea. Not the best photo, look in upper right hand corner. David J.

marklamon · Post by **marklamon** » Sun Nov 18, 2007 11:00

David, I noticed the safety wire method on a 2003 Super Decathlon that I was doing a 100hr on a while back. I used safety wire on my Champ also. Seems like a good idea to me as it allows the stringers to move fore and aft slightly independent of the bulkheads. I noticed a differance during the shrinking process as compared to others that I have done that were glued/nailed and yes I have seen some that were bolted! Mark