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Multiple cable penetrator leaks. Design flaw. (video)

If you have a leaking penetrator, please send an e-mail to support@bluerobotics.com with your order number and we’ll send out a replacement thruster core.

As we are challenging problems with potting maybe it is good to mention that we have leak on 2 years old motor penetrators that were spare one’s (never installed and properly stored in original boxes).
So 2 new motors started to leak after 2 years.
Before that we had problem with 2 more. As we only bought 10 motors, 4 is big number.

Hope that we just got wrong series as I always insist on taking care of equipment. (transportation as maintenance after and before dive). :neutral_face:

Has Blue Robotics considered using some type of plastic penetrator with better adhesion properties than aluminum? PVC maybe?

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I have seen adhesive heat shrink tube been used on the inside, but are people also using it on the outside?

I use Glue Sikaflex 291 on the outside of penetrators.
Looks like rubber when hardened.
I hope that could stop leakage when the cables are compressed at great depths,

Can you post the pictures?


No design prices…
Grind surfaces slightly and clean before glue
(Original epoxyglue is under the Sikaflex)

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You know, if you globbed some of that stuff on and then put some heat shrink over it, it wouldn’t look half bad…

… Most common reason for leaks are to much vaselin or molkycoat, and too tight connector, let the waterpreassure mould the o ribg:) i have No loss in vaccu7m after 2 hrs

Understood. But check the video. The leaks we are discussing here are coming around the epoxy plug.

Ok… Looks like its not cleaned enough before moulding???.. But it if you set it uder waterpreassure, Does it leak? Waterpreassure Will tighten the mould outwards the connector?

Sikaflex is made for letting moisture out? Et least normal Sikaflex… Learned that when i was changing Windows a Long time ago.

… Have anyone trues scotchcast instead of Epoxy?.. A bit softer, so ut Will expand inside the connector but seal it Better?.. Just å thought?

By propper connectors :smiley: i had sucsess with grinding the inside before scotshcast and ca 2 cm og heat shrink as a mould on the water Side Down to 200m gluing directly on anodized aluminium is not the way to go

Sikaflex has a lot of products
291 is a Marine glue and sealant

Is there any risk in having air trapped behind the epoxy if you use heat shrink? (Heat shrink with glue of corse)

I used 3m scotch cast its quite liquid before setting used epoxst/jbweld on the wires so the cast dont leak …