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Cable Penetrator bubbles

Hello, Potted my first cable penetrator yesterday and I have a lot of small bubbles trapped in the resin. I live in Australia and your recommended potting epoxies are not available or difficult to acquire here, so I used west systems g/flex 650. Should I use this or start again? 90m will be my max depth, it was very warm here yesterday and the resin set way too quick .

Hi Saul, we use the same epoxy i wouldnt recommend using it like that. I had one like that before and it did fail.
We are from tasmania so high temprature isnt an issue for us but we have had the opposite issue where it was too cold and the epoxy was too thick for the bubbles to escape. Mix it in a climate controlled area and mix it slowly so no bubbles are introduced seems to give us reliable results with g flex.

Hi Saul,

It’s hard to say if this will cause a failure. 90 meters it pretty deep so I would play it safe if possible. If the bubbles are just at the surface it might be okay but if they are throughout it could definitely be an issue. I would also pull on the cable in each direction and see if there is any delamination between the cable and the epoxy or the epoxy and the penetrator.


Looks very similar to my early attempts with the G-flex sir. Much improved it by leaving the two bottles in hot (80 celsius) water for 10 mins prior. Also heated up my mixing bowl and had it sitting in hot water as I mixed, all at room temperature. Mix slowly, rather than beating like you might with a cake mixture. Pour directly from there or pour into a syringe. I found that sucking into the syringe creates it’s own bubbles.

As I understand it, a tight “ball” of resin will cure quicker than resin that’s spread thinly and there might be an option to warm the resin at that point to encourage bubble to rise and pop, which they do very quickly under applied heat. I have overheated some blanks that I made though, turning it into porride, so some trial and error on some 3d printed test penetrators might be a smart move. Obviously I didn’t apply much heat to the penetrator to cable potting, for fear of damaging the sheath and I’m happy with the results, albeit pre-testing.

All the best in your battles sir!