Solder vs mechanical fasteners

[halfmoa]

I've read on this forum and in other places that boat wiring is not to be soldered, but rather wires are to be joined by mechanical fasteners. Aside of "industry standards" (which in MY profession are often set by manufacturers and vendors rather than those of us with our keesters on the line). What is the reasoning behind this?
I suppose it's possible that the information I read is completely incorrect, which has been the case with many topics I've read about on the net boating related or otherwise,(see my transom post) but I know for a fact that I can solder a splice and make a much more secure connection than any mechanical wire fastener i've ever seen...that's why I learned to solder in the first place!

 

[sdowney717]

Re: Solder vs mechanical fasteners

It creates a hard spot in the wire that can break apart. Solder wire together inline then bend it back and forth a few times and it snaps apart.
I still do it anyway and I have not had it break apart in the boat by itself.
The thinking today is boats make a lot of vibration and movement when running, so that is the same reason you dont use solid copper wire.
But a lot of old boats like woodies were built with solid copper romex and it worked. But still can break. I just rewired my 40 years old old boat AC and almost all the solid wire was still ok. One good thing about solid wire is you dont get corrosion wicking down all those tiny fine strands. That is the reason they want you to buy tinned marine multi strand wire.

I clean old wire for soldering by dipping the end in white vinegar till they come clean. Then rinse in water.

There is NO legal requirement to use marine tinned wire in a boat just an ABYC recommendation, and the USCG says plain multistranded is fine.
ABYC has no legal clout.

When I rewired all the outlet circuits in the boat, I bought a 12 gauge heavy duty extension cord. On the ends I soldered them and then screwed the soldered wire ends to the outlet receptacles. I pretty much soldered all terminal ends including the 30 amp shore power connection end points.
I would prefer to have no corrosion issues with high resistance developing where terminals are creating heat. So I used solder. I also refused to pay for the tinned marine wire price. Where all the wire is in my sedan cruiser, the wire does not get wet.

 

[Silverbullet555]

Re: Solder vs mechanical fasteners

The hard spot is the issue and many people are not good at soldering. If you solder, it is recommended you wire tie the wire just past the solder joint to keep it from flexing.

I solder some and crimp some. If I crimp, I use sealed heat shrink crimps to protect the joint from moisture. Using a good crimper is also important.

I even having solder sleeves that I just started using in some cases. Kind of a cool concept from the aircraft industry but they take some getting used to.

 

[jtexas]

Re: Solder vs mechanical fasteners

When I rewired, I found lots of soldered joints from previous owners, many of which I know had to been in there at least 15 years. Now, this boat's probably never been used more frequently than a couple times a month. I would probably crimp anyway regardless of standards, just because it's more convenient for me.

I use automotive wiring, for reasons of economy and convenience, and can tell you that after a few years of freshwater use, the conductor will show some discoloration, although I've not had any failures due to corrosion in the wire itself.

Not recommending noncompliance, just relating my own personal experience.

 

[bruceb58]

Re: Solder vs mechanical fasteners

The place where the soldering is going to hurt you the most is at ring connectors because the connection is being held rigidly. Soldered splices that are not held tight close to the joint with tie wraps are not as big an issue.

 

[halfmoa]

Re: Solder vs mechanical fasteners

Great answers here but now I've got a followup question...has anyone ever had a soldered connection fail? I'm not doubting that could, but it seems extreme that a soldered connection would fail during normal use. Self edit: I know there are guys that are on the water daily, for a living, or even live on a boat so I know they're getting way more usage put of their boat than I am but still...

And for the record, I just went through my electrical system and found 4 crimp connectors on the verge of failure due to either corrosion, poor crimping or both. All were fixed with solder.

 

[bruceb58]

Re: Solder vs mechanical fasteners

I have never had any connection I have crimped fail but that is probably due to the fact that I use a high quality crimp tool and Ancor crimps. I have had soldered connections fail on the trailer before and on soldered stuff I had done on a car long ago when i didn't know any better.

 

[Scott Danforth]

Re: Solder vs mechanical fasteners

I use uninsulated crimp connectors and then solder them and seal with adhesive lined shrink wrap where ever I can. I also make my own battery cables with the same process utilizing both the mechanical crimp and the solder to make sure there is never a connection issue. I also support all wiring to prevent movement.

A properly done crimp with heatshrink or some other seal is very acceptable. The main reason this is the standard is cost, it takes people to solder harnesses vs a machine to terminate the ends.

 

[bruceb58]

Re: Solder vs mechanical fasteners

The main reason this is the standard is cost, it takes people to solder harnesses vs a machine to terminate the ends.

No, the main reason its the standard is because of vibration tolerance. Its also the reason its a mil spec standard.

 

[zopperman]

Re: Solder vs mechanical fasteners

I just finished all my wiring and used crimps for everything. Then I covered the connections with electrical tape and made sure everything was tight, gave it a few tugs and tested it... I used crimps because i find them easier than solder... also I think USCG req's crimps...

 

[sdowney717]

Re: Solder vs mechanical fasteners

I like the self vulcanizing rubber tape for wrapping wires, I dont like vinyl tape.
Only place I dont use rubber tape is when pulling a wire into a tube conduit.
Believe it or not the blue 3m painters tape is good electrical tape if your hard up and dont have real electrical tape.
The vinyl electric tape comes apart after a while it unwraps and sticky everywhere.

Another good use for HDPE plastic oil and laundry detergent bottles is you can cut these up into long strips and use them to secure wires to bulkheads. Cut a strip the length and width desired, bend it in half and punch a stainless steel screw thru the ends Now you have a cable wire hanger. I have yet to see one of those decay like old nylon cable clamps will.

 

[JB]

Re: Solder vs mechanical fasteners

The "standard" is misunderstood (and mis-stated) widely. Marine wiring is supposed to be fully tinned, fine stranded wire and the connecting hardware is supposed to be tin or tinned, as well. That way there is no junction of dissimilar metals to create corrosion.

The fine stranded wire is very vulnerable to breaking if it has been soldered and it should be crimped.

Quibbling about whether stiff, untinned copper should be crimped or soldered is like putting Michelins on your Yugo.

I usually used copper, crimped it, then flooded solder into the crimp, but not up the wire.