Is wire shrink wrap waterproof?


Need to extend my motor wires and the join is going to be outside my compartment.

Was planning to use multiple layers of wire shrink tube like this to make the join waterproof. Is this going to be sufficient? Or should I look at some kind of waterproof connectors?

There is shrink tube with glue inside, that should be waterproof.

liquid tape the join and then shrink tube

You can also put silicone on the junction of the wires and once dry you put your heat-shrinkable sheath

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Thanks for the info.

Had thought about using something like this so I can detach the mast from the board but they area a bit bulky


Here’s how i successfully used waterproof connectors that can also be disconnected anytime. See my build for details Florida Build - PM Based - #2 by sunrise305 - Builds -

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Thanks @sunrise305 I had actually also been looking in the last few days at a virtually identical item on ebay

Good to know you had some success with these type of connectors



Forum users have designed some clever waterproof 3D printed shells requiring minimum space, tested and provided with STL files :ok_hand::
@Riwi XT150: The other way around - #27 by Riwi - Builds - uses a threaded shell that needs some adjustments.
From @Gobbla
2019-01: _XT90 (OD 12 mm x 57mm long :crazy_face:) French build born in [LYON] - #51 by Gobbla - Builds - no thread, just o-rings.
2019-08: XT150 (OD 14 mm x 70mm long :crazy_face:) French build born in [LYON] - #110 by Gobbla - Builds - no thread, just o-rings.

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I need to lengthen my my motor wires since I hope to use a longer mast than my original build. My current motor wires are not long enough to exit the top of the longer mast.

I am thinking of using a 8 awg butt-splice to extend the motor wires. However I need the connection to be waterproof since the connection will be in the mast.

Any suggestions for a waterproof connection?

Initial ideas

  • solder + conformal coat + shrink wrap?
  • submersible 8 awg butt slices (I found some from Wirefy)
  • should I encase the connection in epoxy?
  • fill the mast up with closed cell foam?
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I solder then put liquid silicone ( liquid tape) twice, then hot glue and warp or the shrinkwarp that comes with glue on the inside.
But i found that corrosion will inevitably comes around sooner or later. Check and redo occasionaly

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You can buy waterproof shrinktube. It is coated on the inside.

Liquid tape is rubber, not silicone. Silicone is far superior for waterproofing connections. A better method:

  • place marine silicone around solder joint.
  • Shrink wrap the wet silicone
  • wait 24 hrs for it to dry

I’ve done this and have connections that are over 3 years old that are still waterproof. The benefit is that if you use silicone cable the bond to the cable is permanent.


Wow. You make silicone stick to silicone! Magic.:joy::joy:

Nice Trolling…

pls tell me how you do that, I am keen to learn


If you do not already know which type of silicone your detail is made of,…

and here comes the problem

Yes, you’re right, could be tested though.

I’d think that cyanoacrylate and salt water won’t be the perfect match, platinum cure won’t work with the tin in the wires so that leaves moisture cure.

i’ve used liquid tape + shrink to seal the joints without issues for three years. I guess the joint with heat shrink protection is still good enough even if the liquid tape could probably be peeled off the silicone if you tried.

I simply use the shrink tube that is already coated with glue on the inside.