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I have a small 5" line (crack) running from the bell end of my case back. It is a clean, linear, though not straight, line. What is the best way to repair this? Should I fill the crack with Gorilla Glue and then cover it with strong duct tape, or should I just cover it with duct tape? Something else?

Thank you for your opinion.

The case is black plastic of some kind - typical to most all brass cases. That is all I know now about it....

I would repair it from the back side... High quality tape keeping the crack closed on the front...Take out padding.. scuff with coarse sandpaper... epoxy.. fiberglass reinforcement.. epoxy... cure... remove tape she put back together.

I would probably drill a “crack stop” hole at the end(s)?of the crack to keep from getting any bigger. This removes the stress concentration at the end of the crack to keep it from getting any bigger. Then repair the actual crack with as suggested.

Eric

Yeah.. good call on stop drilling the crack.

This has worked for me.

...(not PVC glue, but ABS glue)

https://www.oatey.com/products/oatey-ab ... 1230977158

I promise nothing. I don't make it or nor sell it.

I applaud both the crack stop hole (just 2-3 mm needed) as well as any variant of 2-component-glues in combination with fabric reinforcement.
While the initial crack may have required considerable force, growth of an existing crack occurs at far lower loads.
Which means, that after repair and due to differences in elastic modulus between base material and glue, the initial crack might start to grow again after repair. That crack-stopper hole might prevent that.

No need for fancy carbon fiber, btw:
some hardware stores offer sturdy shopping bags made of woven, inelastic plastic fiber. A patch cut out of one of those will do.
Similar stuff is used for large container bags for bulk handling of granulated goods such as food pellets.
Just make sure the material has no water- or airtight coating and can be soaked with the glue.