Subsea in-line coating for tether connection


I just received a Birns Aquamate 8 pin mini-connector to do the splicing between the tether and the ROV.
I thought I could do an in-line connection coating between the tether twisted pairs and the cables of the connector with a 3M in-line splicing kit on both sides but it happens to be far too big to be integrated to the tether.

Has someone any other suggestion for the in-line cables welding protection with 150m pressure rating?

Thank you in advance


Hi Steven,

Is the 3M kit with a plastic mold and thats to big? If its the size of the mold you can use heatshrink and close one end before you pour, having the tether hanging vertical. With a nice size heatshrink you can get the cast a good bit thinner.

Personally I use 3M SCOTCHKOTE as sealing together with self-amalgamating/vulc tape and that will keep you going much further down than 150m if needed.

Hope that answered it, if you want more details I can probably dig up some pictures.

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Thank you for your answer, I guess the scotchkote + tape will be a better option given the configuration. I would appreciate any picture should you have one.


Le mer. 17 oct. 2018 à 04:22, Njål Bragstad a écrit :

I can second the 3M Skotchkote and 3M 23 Self Bonding Electrical Tape process.
Iv seen this hold well beyond 1000m with no issues.

I would try to use rubber bonding tape if possible. Silicon bonding tape will be fine but the rubber tape will last longer with repeated seawater exposure and bending.

With the Skotchkote and Tape make sure you rough up or chemically etch your cable to ensure that it bonds well. Use multiple layers of tape (usually 3 or more) ensuring each layer overlaps the previous and ensuring Skotchkote is applied between each layer.

As a suggestion only, I would advise testing your Insulation Resistance readings before and after your splice process as it can change if your wires move around during a wrapping process.

HOWEVER … it should be noted that the splice is generally not physically strong. It should be used where the tether is not being repeatedly moved around, like close to the penetrator before the thimble. If the join is constantly moved / bent its likely to have issues. This splicing method is typically used on stationary cables.