The tinned copper wire thing.

[BrewGuru]

If you can imagine the wire ever being exposed to salt water then tinned is the only solution that gives any piece of mind to me. For "dry" installations use whatever but when the chips are down and your boat is getting a real thrashing I would be much happier with tinned wire to my bilge pumps

I am with you Horse been doing a bit on mine lately have 5 bilge pumps connected to 4 compartments, prior to my ownership, someone rewired the one just below the galley, when it finally failed the wire was not tinned and had the familiar green/black powder happening all the others which were tinned were as new, being a timber boat it is not unusual to get water in the bilge on occasions, the straight copper is just not up to the job.

[TheRealAndy]

I am with you Horse been doing a bit on mine lately have 5 bilge pumps connected to 4 compartments, prior to my ownership, someone rewired the one just below the galley, when it finally failed the wire was not tinned and had the familiar green/black powder happening all the others which were tinned were as new, being a timber boat it is not unusual to get water in the bilge on occasions, the straight copper is just not up to the job.

Thats ok, but just remember tinned copper wire is not without problems either. I have seen tinned copper wire fail just as badly as plain copper wire. The biggest problem is that most people think that if they use tinned wire then they will never have problems... They are wrong. The most hardy wire I have seen is solid copper wire, no tinning.

[BlackArrow]

I have had 2 boats (one for 13 years) that I have completely rewired with tinned wire, I soldered every joint and terminal and shrinked wraped every joint and terminal and have not had any failures to date. I do not use crimps as they eventually corode between the wire and the crimp giving poor contact, soldering eliminates this and at the same time give a solder seal to the plastic wire covering.

I have heard that soldering hardens the wire and its prone to breaking through vibration, but it has'nt happend to date and that totals 16 years.

For what its worth thats my experience

Blackarrow

[oldboot]

I repared some intercoms in a milk factory once... it wasn't so much the corrosiveness that was the problem but because of the fat & other stuff the circuitry and contacts didn't seem to dry out and gummed up badly and everything stuck to it.... yuck

salt comes off pretty easy if you wash it off... compared to lots of other things.


the worst thibg I ever saw was a machine thet had been pissed on by a rat in a fertiliser factory..........it took all the laquer and the copper off the printed curcuit board and started on the solder.


cheers

[TheRealAndy]

The biggest problem is not the salt, its salt and moisture. Salt will pull out any moisture in the air. The biggest problem you will find with cabling is that the moisture travels up the wire when its damp, then back out when its dry. That means any connection will be wet at all times. That intself is not so bad, the problem comes when you have both power and ground in the same join.

So if you must make a join or a connection then you should make it in a place where you can inspect it regularly. Also do not make connections in places where you know it will get wet (think bilge pumps).

[oldboot]

Andy makes a very important point.
It is very important to keep your joints and terminations dry and as protected as possible.... and for that matter avoid joins where ever possible.

And this is why I raised this issue, there are so many out there who are zellous about tinned copper wire but are very sloppy about very basic workmanship issues

afterall tinned copper will only buy you some time.

I know a rather well known boating identity that boasts, he rewires his boat every 12 months....... .......and he wont use crimp lugs..... ......yeh he uses his boat every day and it must meet survey....... BUT....it occurs to me that if you were that keen you would be better beeing incredibly fussy and doing it right...... I can not see any reason that a " properr job" should not last many years.

cheers

[foxx510]

I have heard that soldering hardens the wire and its prone to breaking through vibration, but it has'nt happend to date and that totals 16 years.

Blackarrow

Yeah I reckon that one's a crock. There has to be a transition from solid object to stranded flexible wire somewhere, solder or no solder. If vibration looks like it will be an issue, you have to account for it regardless. I solder all my crimp lugs, and add heatshrink and hot glue to seal and address the vibration problem.

[PADDLES]

no crock mr foxx, we have had this problem in our rally car, it does shake, rattle and roll a bit more than a boat but we found that if we soldered crimp lugs the conductor snapped. heat shrink would help support the conductor where it goes into the solder though.

[oldboot]

No it most definitely isn't a crock.
I do not intend to offend anybody, but this is a very popular and incorrect practice on crimp lugs.

Solder fills the gaps in the strands of wire and makes it rigid.....the solder also wicks up the cable beyond the connector...... how far depends on a number of factors.

What you then end up with is a well defined point where flexible meets rigid..... very often this point is well beyond the connector.

This can be proven in a bout 5 minutes with piece of wire, some solder and a soldering iron.

All good connectors and wiring systems support the cable at a point where it is still flexible.............this point does not produce the sharp and well defined transition that a soldered joint does.

Now on to crimp lugs.
.......soldering crimp lugs is not a good idea.
If the lug is properly crimped, soldering will not improve its performance or reliability in fact it will do the opposite.

If a lug is properly crimped the metal in the lug and the metal in the wire a forced together with sufficient force to exclude all air and press the metal into one solid mass so as to be almost welded.
I have cut corroded crimp lugs off corroded wire and broken the luggs appart to see wht was going on...... firstly the crimp is very difficult to get appart and the metal within the crimp is bright and clean in comparison the the metal immediatly adjacent that is black & green and badly corroded.

Good quality insulated crimp lugs were developed for the aircraft industry where vibration is a very big issue.

the lug has a number of features.....there is the crimp tube it self, which terminates on the wire as described above.....over that in the plastic sleve whic is designed to crimp down and provide strain relief on the cable......in crimping the front part of the lug , as well as making the electrical connection this anchors the plastic sleve to the connector.......the back section is also crimped down in the insulation providing a graduated strain relief.

the main corrosion problem with ( correctly applied ) crimp lugs is where the insulation on the wire ends.....the best solution for this is either heatshrink lugs or applying corosion inhibiter.

if you solder a crimp lug you are most likely not getting any solder ito the joint but simply getting it on the surface of the lig and filling the wire up and making it stiff.
This then make the plastic on the lug completly useless as a strain relief because you have provided a point for failure beyon the strain relief.

This soldering crimp ligs is very common among mechanics......Don't know why but it is a very popular misconception.

there is a further problem...... even if you use resin cored solder (the correct solder) the remaining flux is hydroscopic and provides fuel for corrosion.
In quality electronic manufacture and repair we scrub this flux off our printed curcuit boards with alcahol...... but you cant get it out of the wires.

It is important that crimp lugs are applied correctly
...they must be good qulaity lugs
... they must be the correct lug for the size of wire, use the smallest size that will fit the wire, if the tube is not at least 75% full of wire, the lug will not crimp properly.
...they must be crimped properly..... many of the cheap crimpers simply will not do it....you can not properly crimp a lug with pliers or those funny things in the back or wire strippers........when crimping with ordinary ( non ratchet) crimpers you should feel the lug squash then bottom out & go hard.... many people will give the lug an extra go with the next smaller section in the crimper just to make sure.... on a simple crimper this is reasonable.... not with a pro ratchet crimper.

then you should test the lug......grab the lug with hand or pliers and the wire with the other an pull......as hard as you can.......the wire should break before the lug lets go........in high reliability workplaces they have little straing guages for this.

A similar and related issue is the tinning with solder of wires to be put in screw terminals...... this also os not wise....... to such an extent that AS3000 specifily states that any wires terminated by clamping between matal surfaces shal not be tinned...........( this does not refeer to tined strand wire as the original thread)

anyway

cheers for now

[foxx510]

Fair call, happy to accept that my methods are incorrect. I guess if the military and aircraft industry crimp, then it must be the best way. None of my soldered crimps have failed though yet, I guess the heatshrinking I do supports the wire sufficiently. Thanks for the info though oldboot, very informative posts.

[Twisted_Pair]

Quality of terminations......I am gob smacked at how much marine electrical gear has screw terminals or unplated spade lugs.
I am convinces that lots of people don't know how to use a screw terminal correctly..... or are careless in stripping wire
How many people (including professionals) are using crimp lugs with cheap crimpers..... or even worse pliers
Soo often I have seen the wrong sized crimp lugs for the wire used.

Couldn't agree more,
Correct cable + correct crimp + correct ratchet crimper = qaulity termination.

Regards, T_P

PS I do like tinned cable on boats tho!

[oldboot]

noting to be ashamed of foxy........I have never seen proper crimping technique discussed in any books........I picked up the technique from older well informed tradesmen and better informed mates.

for those outside the trade..... this understanding isn't common.

I have to say I love my crimpers.....( i think at last count I had 8 different types)

A properly made crimp joint is a beautifull thing and so quick.

I also love heatshrink tube.

A crimp lug with adhesive filled heatshrink is just pure filth to me.

Oh oh oh...... I gota go and crimp some lugs

cheers

[fRuItCaKe]

I just bought a new set of crimpers. They do the 3 small bootlace lugs and red and blue, all in one and are made out of titanium! Very light, unlike my old ones which weigh half a tonne.

[TheRealAndy]

noting to be ashamed of foxy........I have never seen proper crimping technique discussed in any books........I picked up the technique from older well informed tradesmen and better informed mates.

for those outside the trade..... this understanding isn't common.

I have to say I love my crimpers.....( i think at last count I had 8 different types)

A properly made crimp joint is a beautifull thing and so quick.

I also love heatshrink tube.

A crimp lug with adhesive filled heatshrink is just pure filth to me.

Oh oh oh...... I gota go and crimp some lugs

cheers

I must have about half a dozen ratchet crimp tools, as each one is only good for one type of connector. Jaycar sell a crappy one that you can change the heads on, so you can have one tool that does many jobs..

[oldboot]

I just bought a new set of crimpers. They do the 3 small bootlace lugs and red and blue, all in one and are made out of titanium! Very light, unlike my old ones which weigh half a tonne.

Can I see them, can i touch them, do they have smooth silky action, or do they have a satisfying zzzzzzzzip, ksnick.......will you love them forever

cheers