Fabric transition, upper longerons to vertical tail

[rodsmith]

Finished the exterior fuselage fabric. I did the sides in one piece including the vertical tail. I used the airfoil shaped wood strips on the vertical tail ribs. On the left side the fabric is tight to the wood strips. Due to the offset of the vertical tail, on the right side lower rib the fabric is about 1/4" above the rib. Stewarts fuselage video says to just use a few stiches and don't pull the fabric down to the rib. With all the tail vibration, especially with a big engine, I'm thinking I want to use a 2" stich spacing and pull it to the rib. The fabric profile looks real nice, hard to visualize what it will look like pulled down to the rib. Looking for advise on this.

[jaredyates]

The advice I would have is fix it to your liking before you progress in the process. If it turns out in a way that you don't like, it will never be cheaper or easier to fix it than it is now, and it will bug you for years if you don't. I would be inclined to remove the covering from that area, create a thicker wood rib, and reapply. Or install new fabric and don't shrink it as much. That's not to say it necessarily requires fixing, since you are the final authority on all cosmetic questions.

[rodsmith]

After further thought, I'm going to stitch it tight to the rib and see what it looks like, can easily be undone. I like the thicker wood rib idea but afraid the way the Stewarts glue sticks fabric to fabric, I would end up removing fabric on both sides of the tail, don't think I am ready to do that. Removing the T88 glued wood could be interesting also.

[robcaldwell]

I came across the same situation on my V Stab. Instead of rib stitches I’m using rib rivets. I installed all of the rivets (3” spacing) except the forward 3 rivets on the bottom rib starboard side. I experimented attaching the front 3 rivets to the rib but that created too much pucker and really looked bad. So the front 3 rivets are in the fabric to complete the look, just not anchored to the rib. At the full 350 degree shrink there’s not much give considering the compound shape of the fabric at that location.

[Mark Goldberg]

This situation is a little more easily managed if the fabric down below the vertical stab is not shrunk quite as much. Not to the 350 degrees called for. Mark

[robcaldwell]

Stewart Systems stressed hitting 350 to avoid fabric sag later on. There's probably a fine line as to how low to go without risking sag, but they wouldn't say.

[Battson]

If you stitch it tight, it will pucker to some extent, if it's only a half inch you might be OK... But it could look nasty.

I stitched it and I got away with it, the tape hid the pucker.

If it can beat against the wood underneath then it will wear a hole in the fabric unless you stitch it. Then you'll be tearing the fabric off the tail in 5 years time anyway. I would pull it tight against the rib. It should move a half inch. The first stitch will look awful, but once you do 2" stitching the whole way along it will come right, hopefully.....

[rodsmith]

It was only a 1/4" off the wood strip in the center, flush the first few inches from each end. I stitched it tight last night, still looks good even without the tape.

[whee]

Sorry I'm late to the party but I'm glad you got it sorted.

I had the same situation and stitched mine tight using whatever spacing I pulled from the table on AC43:13. I think it was 3" with the first two stitches being 1.5" apart.

Can almost see it in these pics: