Crimping versus Soldering

[Cruisingdad]

I am not trying to bring up another very heated argument on this board, but I would like to tell anyone still soldering that almost without exception, EVERY soldered joint on the V-42 we have is corroding and failing. It may have taken close to 20 years to do it, but we did not find these issues on ANY of the crimped joints... NONE.

If that is not a first hand testimonial to crimp over solder, I do not know what is.

- CD

[halekai36]

That has been my experience too. I've re-wired my fair share of boats over the years and without question the soldered joints are the ones to fail, corrode or both.

The other thing I've found is the wires tend snap just above the solder joint. This is probably due to solder creep which makes the wire more brittle because it's now, in a sense, a single conductor wire and has lost it's multi-strand flexibility.

I do a two part process with a proper marine grade crimp usually made (or sourced) by Anchor and then over that I use adhesive lined heat shrink and melt it down with my heat gun..

[sailingdog]

I've seen soldered joins fail, and often far sooner than a properly installed crimp with adhesive-lined heat-shrink will. As Halekai has pointed out, they're far more subject to fatigue than a properly crimped join would be, since the solder does effectively convert the nice flexible strands into a single solid stiff wire.

A bunch of hints to making a crimped connection that will last.

First, use a good ratcheting crimping tool, which will allow you to apply fairly consistent pressure on all of your crimps. Non-ratcheting crimpers will not give a consistent amount of pressure on the crimp.

Second, use good marine-grade crimp terminals—non-marine grade ones will corrode out rather quickly.

Third, use good marine-grade tinned wire. Marine grade wire is pre-tinned, and has more, finer strands, for greater vibration fatigue resistance.

Fourth, use a decent adhesive-lined heat shrink tubing. The adhesive lining is what really makes the connection waterproof. Don't skimp on this step.

[rkfitz]

I second sailingdog. The only reason for soldering wires is because marine grade tinned wire is not being used, and it is an attempt to protect the copper wire. Tinning the wire yourself also leaves it stiff and subject to stress and vibration fatigue. In addition, standard pvc insulated wire is not waterproof. A quick immersion in water (I don't know where from, maybe your bilge pump is shot or you're sinking) could very quickly open a live wire internally.

[sailaway21]

And none of the old threads discussing this wouldn't have been adequate to revisit the issue?

[teshannon]

I have no solder joints, all crimped with heat shrink. SD, I like your idea about a ratcheting crimpimg tool. I will get one.

[sailingdog]

Yea of little faith...you're doubting the great and all powerful Cruisingdad...

Originally Posted by sailaway21

And none of the old threads discussing this wouldn't have been adequate to revisit the issue?

Damn... I said that with almost a straight face.

[sailboy21]

Somewhere I read that when you solder wire, you degrade the insulation due to heat, which causes it to become caustic and start the corrosion process.. I never use solder on the boat except for electronics repair, or tinning ton-tinned wire (instrument wire is notoriously bare copper)

[sailingdog]

Degrading the insulation doesn't probably make it caustic...but it probably does make it more porous, leading to moisture getting in and kicking off the corrosion process.

Some insulation might be PVC-based and as such, heating it might release Hydrogen Chloride gas...which when added to water becomes Hydrochloric acid.

[maccauley123]

I have heard of brush on electrical tape being recommended over heat shrink tubing. Because it goes on as liquid it fills in the connection very well and when it hardens creates an exception seal.

Any experience with this?