Cowl Piano Hinge starting to Zipper

[keijidosha]

Pulled the cowl for an oil change and found the first three tabs on the upper front side of the upper/lower cowl piano hinge broken off. I heard them clatter into the bottom cowl as I pulled the wire pin out the front.



I'm the second owner. Can the hinge be replaced? If so, can the damaged segment be replaced or does the whole hinge have to go?

Airframe has 130 hours TT. Also have a call out to get the engine/prop dynamically balanced (better late than never I guess).

[Beancounter]

Matt
you can probably cut off just the damaged section and replace, however alignment will be important. Try to keep it straight by inserting the pin and the other half of the piano hinge when you drill the rivet holes. Drill one hole, cleco it, repeat. You may want to put a doubler over the joint to reduce flexing.

[Steve Barnes]

Both my RV's have done this. It just screws up the paint job a little. Bean counter has it right. Be sure to use a mini rat tail file and file the inside square corners of the new segment of hinge (stress risers).

Steve

[David Paule]

Might be worth getting the more expensive extruded piano hinge for this. Van's sells it and so does Aircraft Spruce and probably other vendors. You can get it in the same size.

Dave

[BillSchlatterer]

Assuming you are using the undersize hinge pins. The larger ones that come with the hinge put a lot of stress on the eyelets in any kind of curve ....

Bill

[Carl Froehlich]

Originally Posted by David Paule

Might be worth getting the more expensive extruded piano hinge for this. Van's sells it and so does Aircraft Spruce and probably other vendors. You can get it in the same size.

Dave

+1
I put an extruded hinge on the left bottom cowl for the same reason. Problem solved.

Carl

[keijidosha]

Originally Posted by David Paule

Might be worth getting the more expensive extruded piano hinge for this. Van's sells it and so does Aircraft Spruce and probably other vendors. You can get it in the same size.

Dave

Originally Posted by Carl Froehlich

+1
I put an extruded hinge on the left bottom cowl for the same reason. Problem solved.

Carl

Good tip. Ordering the extruded hinge.

[keijidosha]

To attach the hinge, plans call out AN426AD3-4 (Hard) Rivets. Instructions have a note saying ?when setting solid rivets in fiberglass, use soft (AN426A3-4?) rivets or do not fully set normal rivets." Any advice on preference?

[Steve Barnes]

I would use the regular rivets and under squeeze them so as not to stress the glass.

[az_gila]

Originally Posted by Steve Barnes

I would use the regular rivets and under squeeze them so as not to stress the glass.

Also drill 1/4 inch holes in between the rivet holes and embed the hinge material in epoxy when riveting. The epoxy will flow up through the holes and add some strength.

I could hear the glass "creaking" hand squeezing rivets in the old white cowls, but didn't get the same effect in the new, much harder epoxy Pepto-Bismol colored cowl.