Stringer fastening - Pro and Con

[DBeaulieu]

All good suggestions, thanks for the replies!

[podo]

Any reason not to final size drill and fix in place the top and bottom stringers?

You may need to step inside the fuse for interior covering. Not having bottom stringers installed would help this.

[Nev]

Mine were installed pretty early on and was able to work around them. No real issues with that.

[DBeaulieu]

Okay, I think this is the solution to the "problem" stringer. Plan on notching tab flats (see green lines on pic) the width of a 6-32 machine screw, place stringer in position, scribe for drilling, remove stringer, drill #28 for screw, insert screw loosely, position stringer and clamp with screw and nut. Certainly will prevent lateral movement due to fabric force, and fore/aft movement is fixed via other stringer attach points. Now, back to trying to figure out window frame attachments...

Stringer safety solution.jpg

[DBeaulieu]

That is a small test piece in the pic. Smooth side is outboard on my stringers (except one) which I did not notice while doing the bending and shaping.

[alaskabearhawk]

Looks like a great solution!

[arborite]

Very creative solution.

Are you installing the grooved edge of the stringer on the outside? I assumed the smooth side was out. does it matter?

[Bcone1381]

Very creative solution.

.........does it matter?

My view is that it does not matter. Those grooves do provide a drilling "Target" when drilling holes to install the rear window frame....you'll easily see if your drill starts to wander off its target. (which may mean your drill point is slighty dull....toss it and get a new one from your inventory).

With that being said, Fabric will taouch the stringers of course. The 90 degree corner of the stringer could rounded with a filed or sanded to make the transition a slight bit easier on the fabric. I did not do that with mine because it was too late when I discovered that technique, and I still wonder if that thinking is a bit anal-retentive. Thats where perfection prevents completion.....as Mark G says. These should be covered with Chafe Tape before covering with fabric.

[DBeaulieu]

Agree, does not matter whether smooth or grooved. Had a buddy AP/IA who has been to the Polyfiber school and specializes in ragwing restoration etc. He said no need to "break" or smooth the edges on the stringers. I'm going to take his word on that and save myself the little bit of effort/trouble.

[podo]

These should be covered with Chafe Tape before covering with fabric.

Brooks, do you mean the entire length of the stringers?

[Bcone1381]

Yes. I applied the cotton chafe tape the entire length of all stringers. With that being said, this is the internet and proceed with caution. I’ve only covered one aircraft but followed the advice of my Stewart’s system class instructor.

[alaskabearhawk]

I eased over the corners of my stringers just a bit on mine using a Vixen file. It went pretty quickly, but probably not necessary. My SuperFlite handbook recommends putting anti-chafe tape over sharp edges, metal seams, protruding screws, bolt heads, nails, rivets. I put the tape along the entire length of the stringers...cheap insurance.

[rodsmith]

I did likewise, believe that is best practice for a covering job.

[DBeaulieu]

agree...not a whole lot of effort to soften the outboard edges...you guys have talked me into it