Waterproof wire connectors have many uses around the boat, but finding a compact, reliable and low-cost connector has proved quite a challenge.  After hours of internet searching we found a great solution – the Solder Butt Connector.  What we are looking at here is not a waterproof connector plug where you can plug and unplug the electrical connector, but a waterproof way of permanently connecting 2 electrical wires.  Our search for a solution first came about when we wanted to find a way of extending bilge-pump wires because sometimes the wires that come pre-installed with a bilge pump are not quite long enough to reach where they need to go.

After getting hold of some samples of these Solder Butt Connectors we were keen to test how well they worked, what we needed them to do was:

  • Make a good electrical connection
  • Make a waterproof joint
  • Be mechanically robust

What we found was that these waterproof wire connectors could achieve all of these needs brilliantly, but only if you install them in the right way – you need to know the trick, so if you watch the video do keep watching to the end!


Waterproof wire connectors can be purchased from our website at Boat Fittings at the following location:

https://www.boatfittings.co.uk/collections/waterproof-connectors-outlets

In our demonstration of how these Solder Butt Connectors work we try 2 different methods of joining.  In both cases we bring the strands of copper wire together to interlink together in the same way.  In the first test (with the Red / Brown wires) we bring the waterproof wire connector into position and simply heat the assembly with a micro-gas torch until the shrinking of the heat-shrink part, and the melting of the solder ring has been completed.  At the same time the band of sealing adhesive melts to make a nice water-tight seal to each of the 2 wires – it looks great (but do check out what happens at the end of the video)

In the second method we pre-solder the wires together – any usual method will do, using multi-core solder which achieves a good flow of solder into the strands of the 2 wires – ensuing a good mechanical as well as electrical joint.  Then we bring the waterproof solder butt connector into position and repeat the heating / shrinking / solder-melting process like before.

On the face of it both of the finished joints look very similar, but check out their behaviour  - please watch to the end of the video to see what happens!

Waterproof wire connectors are useful to extend existing wires or wiring in your boat or marine equipment.  We think you will find these Solder Butt Connectors very handy in these situations.