- Joined
- Nov 30, 2021
- Messages
- 25
- Reaction score
- 16
During the preflight the other day I discovered the left eyebrow was cracked near the front left mount (see picture). I reviewed the applicable threads on eyebrow issues and recommendations to repair cracked eyebrows. I've never done metal work before, but I am fairly handy and can do most mechanical types of things with the appropriate guidance. What would be greatly appreciated is a list of steps and materials needed to accomplish this repair.
Sounds like the basic gist of the repair is to drill a "stop hole", get a 24 gauge sheet of steel, shape and cut steel to size, bond with JB Weld to the inside of the eyebrow, drill and apply rivets, prime and paint.
Beyond what I wrote I have little idea how to proceed. Lots of basic questions, like:
1. Where do I get the steel? Any specific type of 24 gauge steel?
2. Recommendations on how to shape the steel to the eyebrow?
3. Any guidance on how to interpret AC43.13-1b for this type of repair? My understanding is the patch needs to be no less than 2x the length of the crack and the rivet spacing is at least 3x the rivet diameter. I'm a little unclear on how to use (or which is the applicable table) tables 4-9, 4-10, 4-11 (details rivet size and minimum number of rivets to use)
4. What type of JB Weld would you use?
5. What type/brand of rivets would you use and how did you apply them? Flush or standard rivets? If flush rivets, do you dimple the aluminum and countersink the steel backplate?
6. What type/brand of paint would you use?
I apologize for what must seem like basic questions. This is my first adventure into aircraft ownership (and I've only owned the Cub for 2 months!).
Thank you in advance for any assistance you can provide!
Pablo
Sounds like the basic gist of the repair is to drill a "stop hole", get a 24 gauge sheet of steel, shape and cut steel to size, bond with JB Weld to the inside of the eyebrow, drill and apply rivets, prime and paint.
Beyond what I wrote I have little idea how to proceed. Lots of basic questions, like:
1. Where do I get the steel? Any specific type of 24 gauge steel?
2. Recommendations on how to shape the steel to the eyebrow?
3. Any guidance on how to interpret AC43.13-1b for this type of repair? My understanding is the patch needs to be no less than 2x the length of the crack and the rivet spacing is at least 3x the rivet diameter. I'm a little unclear on how to use (or which is the applicable table) tables 4-9, 4-10, 4-11 (details rivet size and minimum number of rivets to use)
4. What type of JB Weld would you use?
5. What type/brand of rivets would you use and how did you apply them? Flush or standard rivets? If flush rivets, do you dimple the aluminum and countersink the steel backplate?
6. What type/brand of paint would you use?
I apologize for what must seem like basic questions. This is my first adventure into aircraft ownership (and I've only owned the Cub for 2 months!).
Thank you in advance for any assistance you can provide!
Pablo
