Making watertight Splice in Humid bilge area environment

[Bigapple1]

Looking for some tips in making a splice that is sealed enough so that humid salt air, will not affect the splice and wiring joints.


Issue in the last 4-5 years, twice I thought I had made a good splice of the wires from a new bilge pump to a longer wire needed to reach the battery. (wiring provided with pump barely long enough to clear the bilge area)


In both case, the damp environment allowed the wires to corrode, and break off right at the splice – even though the splice crimp was tight (wires did not pull out of the butt connector; copper wire had corroded)

1. Original splice method – First, insulation was taken off the butt splice connector
2. Wire were crimped, then solder flowed to ends of connector to seal butt joint
3. completed splice was wrapped & sealed in hi quality electrical tape
4. This splice was located at the top of the bilge area, not subject to water, but when floorboards are down and engine compartment closed – it could likely be a damp area
5. Boat is not a 'leaker'. There is likely only a couple of inches of standing water in a 15 or so inch bilge depth.

What are some ideas that can be used where a splice has to be in a damp marine environment?

• use shrink sleeving over joint (not sure the seal would be tighter than use good quality elect. Tape)
• I've seen references to people applying Permatex Liquid Electrical Tape over a joint
• don't think Silicone sealer would properly bond to wire insulation - ???
• other thoughts?

[rbk]

Replace electrical tape with a good heat shrink tubing (kind that has sealant inside) 1000x better than elec tape.

You’re using tinned wire right?

[newhaul]

Using the crimp connectors with dialetric grease in the ferrule and heat shrink on the outer. Always works great for me.

[rich.drennan]

Originally Posted by newhaul

Using the crimp connectors with dialetric grease in the ferrule and heat shrink on the outer. Always works great for me.

Do not use solder. Use quality heat shrink butt connectors with proper crimp tool and heat gun. Can add heat shrink tubing over that if you really want to double up. Support wires every 12" max.

[Paul Elliott]

I like the hot-glue-filled heatshrink crimp connectors. A little dielectric grease in the ferrule is a good idea, but don't let the grease get on the wire insulation where the glue goes.

There are several sources for these connectors. Here are two: https://www.amazon.com/Ancor-Heat-Sh.../dp/B01GJ97AXA (the heat-shrink, not the nylon ones)

Heat Shrink Terminals Adhesive Lined Wire Connectors

[newhaul]

Originally Posted by rich.drennan

Do not use solder. Use quality heat shrink butt connectors with proper crimp tool and heat gun. Can add heat shrink tubing over that if you really want to double up. Support wires every 12" max.

I never said to use solder . dialetric grease ( electrical grease) . and heat shrink

[GordMay]

Greetings and welcome aboard the CF, Bigapple, & Rich.d.

All good advice, so far.

[Dsanduril]

Originally Posted by newhaul

I never said to use solder ....

No, but the OP said he did use solder in the butt connectors.

Don't use solder. In a damp environment it leads to rot right at the end of the solder. Current boat has solder, wire is all fine, but it rots/breaks right at the solder joints - to be replaced one of these days.

Heat shrink with sealant/glue is your friend, or, if that is difficult for some reason a self-amalgamating butyl or silicone tape (usually sold for antenna connections).

[BlueChicago]

I have used silicone loaded wire nuts around the house. Can these be used in wet areas on a boat?

https://www.amazon.com/DryConn-62225...cone+wire+nuts

[Lepke]

I been on many old boats and dealt with many failed crimped connectors. I always solder, I have no faith in only crimped connections over time. Besides shrink tape, I use a product called Liquid Tape (Amazon) that has a brush applicator attached to the cap like a glue product. UL listed for extreme environments, stays flexible.
https://www.amazon.com/Gardner-Bende...uid+tape&psc=1

[newhaul]

Originally Posted by BlueChicago

I have used silicone loaded wire nuts around the house. Can these be used in wet areas on a boat?

https://www.amazon.com/DryConn-62225...cone+wire+nuts

NO. Twist wire nuts have no place on a boat. They are for a house or other static situation. Not mobile platforms.

[skipmac]

Originally Posted by Lepke

I been on many old boats and dealt with many failed crimped connectors. I always solder, I have no faith in only crimped connections over time. Besides shrink tape, I use a product called Liquid Tape (Amazon) that has a brush applicator attached to the cap like a glue product. UL listed for extreme environments, stays flexible.
https://www.amazon.com/Gardner-Bende...uid+tape&psc=1

Had a friend that was ex-Navy and worked on wiring and electrical on ships. He told me the Navy used crimps without solder. My experience with solder has been the same as Dsanduril. Over time the connection fails at the solder joint. A proper crimp, properly sealed with heat shrink connectors should last the life of the boat. I do like the liquid tape in a bottle. It's like a belt and suspenders if used on top of a heat shrink connector.

Electrical tape. There's no such thing as high quality electrical tape. I hate the stuff. After a year or so ALL of it turns into gooey junk that peals off and leaves a gooey mess behind. The only tape I will use is the self amalgamating tape.

[senormechanico]

I solder everything, always have since 1970's.
When the connection goes to a terminal strip, I solder to ring terminals, and properly support the wiring.
My boats have had all the toys, too.
Imho, solder is fine if you aren't a klutz at it. It does require a bit of attention to detail.

I actually have had solder failures, but not in my wiring, it's been the lead free stuff that passes for solder in circuit boards like the Raytheon/Autohelm 4000 autopilot !

[stormalong]

Crimps won't fail if you use a ratcheting crimper. A cheap hand crimper is destined to fail. Soldering causes a hard spot next to the solder that will fatigue crack. Heat shrink with glue will prevent moisture ingress.

[Cadence]

Originally Posted by Bigapple1

Looking for some tips in making a splice that is sealed enough so that humid salt air, will not affect the splice and wiring joints.


Issue in the last 4-5 years, twice I thought I had made a good splice of the wires from a new bilge pump to a longer wire needed to reach the battery. (wiring provided with pump barely long enough to clear the bilge area)


In both case, the damp environment allowed the wires to corrode, and break off right at the splice – even though the splice crimp was tight (wires did not pull out of the butt connector; copper wire had corroded)

1. Original splice method – First, insulation was taken off the butt splice connector
2. Wire were crimped, then solder flowed to ends of connector to seal butt joint
3. completed splice was wrapped & sealed in hi quality electrical tape
4. This splice was located at the top of the bilge area, not subject to water, but when floorboards are down and engine compartment closed – it could likely be a damp area
5. Boat is not a 'leaker'. There is likely only a couple of inches of standing water in a 15 or so inch bilge depth.

What are some ideas that can be used where a splice has to be in a damp marine environment?

• use shrink sleeving over joint (not sure the seal would be tighter than use good quality elect. Tape)
• I've seen references to people applying Permatex Liquid Electrical Tape over a joint
• don't think Silicone sealer would properly bond to wire insulation - ???
• other thoughts?

If you know a telephone or power company lineman. Beg borrow or steal some of the sealant they use underground.