Weird Fin Damage

I launched my Estes Honest John this evening for about the 6th time? since completing it months ago, and upon soft recovery on nice soccer field grass, I noticed this fin damage pictured below. Has anyone seen this type of damage before? I can't figure it out, it's not on the same side as the launch lugs, so I can't believe it would be from rod whip. It's my guess that it could be from the shock cord, or possibly the nose cone impacting the fins upon event?
Launched on a D12-5, chute deployed right "about" apogee, maybe a second after. Winds were about 4mph, shock cord is Kevlar up to about 1/2" below the end of the BT, then a piece of airline tubing is epoxied on to prevent zippering, followed by about 3' of 1/4" elastic.
Any recommendations on repairing this airfoiled fin? I was going to repair by bending back, sanding, wood filler, sanding, and then touch-up paint.
Thank you!

It is possible that the elastic shock cord bounced the nose cone back into your fin. I've had similar things happen. Are there are any marks on your nose cone?

For repair, you could consider bending back, wicking thin CA into the cracks, and then filling / sanding / finishing.

No marks at all on the nose cone... i looked under a bright light closely, not a scratch. Thanks for the advice on the repair!

Nosecone is my guess too, I’ve had it happen when I’ve used too short a length of sewing elastic as a shock cord. Not to say it’s impossible with Estes rubber elastic.

I’d repair the same way too, carefully bending it back to shape Then wicking CA in and sanding, wood fill, and paint the fin.

There's damage on the opposing fin as well. Don't laugh at the terrible fin fillets... I was in a hurry but I can't remember why

Nosecone Strike. Balsa is a lot softer than that painted nosecone.

I think you all may be right.. Thanks for taking a look, and for the advice on repairing. Maybe I'll post a pic of the fins after fixing.

If you have something like a Snarky, then you can compare the “teeth” marks on the fin against the mouth on the nose cone for more definitive forensic evidence. Sorry if this comes across as snarky, I am truly sympathetic. Bummer to have damage on a nice rocket, mysterious or otherwise. If you have room, add about 3 feet of Kevlar to the line.

GlenP said:

If you have something like a Snarky, then you can compare the “teeth” marks on the fin against the mouth on the nose cone for more definitive forensic evidence. Sorry if this comes across as snarky, I am truly sympathetic. Bummer to have damage on a nice rocket, mysterious or otherwise. If you have room, add about 3 feet of Kevlar to the line.

Click to expand...

LOL! That's a good one. I think I'll lengthen the shock cord, yes. Just measured what it currently has with a tape measure, it's just shy of 4 feet - about 3'10" in length for a 23" long rocket. I'll try to get around 7-8 ft. of cord.