11/08/2026
Nearly a boat fire!
Failure occurred due to saltwater corrosion, not due to poor crimping etc.
This is a simple relay that is for a toilet.
Its behind a panel and customer found it by chance!
Fault caused by leaking window on a very nice yacht.
I often see wires burnt out, mainly due to poorly crimped inline crimps or poor eye / lug crimping.
Apart from the pic of the damage, the other pic is of a new inline crimp that was done by a professional, the crimp is fine but obviously used the wrong die to crimp with as it pierced a tiny pin prick hole through the heat shrink. This could easily be just a few weeks old here in cairns and already oxidized. It's for a high current charger so if not repaired could result in a fire.
My first rule is.. purchase a decent crimp tools not cheapo rubbish!
If you crimp a lug / eye crimp etc always try to pull the crimp apart HARD, if it comes apart it's no good. Second, I always use self-amalgamating tape or dual-wall, adhesive-lined (glue-lined) polyolefin tubing. I usually use self-amalgamating tape to cover joins in wires in bilges etc and years later when I remove it the wire is still clean and can be reused!
Once a wire is oxidized it cannot be joined! Always use copper tinned wire!
Never use cheap crimps. Many brands of Adhesive Lined Heat Shrink Terminals are not that good but brands I use like Ancor, FTZ, and CABAC Lined Heat Shrink Terminals are very good to use in areas that do not get salt water on them but are ok in the tropics. The reason I say this as the plating is thin and the salt water will eat through it quickly. Fine if it gets fresh water on them.
I often use Narva crimps, and the reason why is they are thicker copper tinned, so they crimp better than other eye crimps. But they are not weatherproof unless you wrap them. If it's an eye crimp I often crimp AND solder (mainly if used for high current over 10 amps) and then use self-amalgamating tape or heat shrink. A bit old school but great for quick reliable repairs but doesn't look as pretty but gets the job done and works well in salt water wet areas!
For wire over 6mm you need to use a copper tinned lug. I also wrap these with self-amalgamating tape or adhesive lined heat shrink if not in a heavy duty salt water ingress area.
For inline crimps don't cheap out. I often use a "naked" thick link crimp and again use self-amalgamating tape or adhesive lined heat shrink to cover! If under 5mm I usually solder and use heat shrink / self-amalgamating tape!
Heat shrink is never perfect as the epoxy will eventually break down, quicker if in the sun and not UV stabilized or not be perfectly snug causing moisture to move into connecter.
I also recommend on battery terminals and lugs spraying them with battery terminal protector and for all busbars / power posts / even switch panels (especially on tinnies) I go nuts using Inox MX4 Lanox Lubricant or recently I have started using Lanotec Electrical Grade Lubricant, its a bit "watery" but will still protect it somewhat from the elements.
