Soldering three cables

[PaulRainbow]

Not in my expereince. Very unreliable and I've replaced many on trailers. If I was given a pack I would bin them on the way home.

By sheer coincidence, i attended a boat yesterday with intermittent starting issues. A dodgy pin in a Yanmar multi plug and been bypassed by splicing a cable with Scotchloks. As they are not corrosion resistant in any way it had corroded and was causing the problem.

 

[wonkywinch]

When I was taught to solder, the first thing to do was mechanically secure the parts to be soldered, eg cut and fold component legs over on the other side of the circuit board or use pliers to secure the wire to a tag first. Then solder so that no mechanical strain was ever placed on the soldered joint.

Similarly, single core cable has no place in a place where vibration/movement exists, yet I still see, even on this forum, photos of single core domestic twin and earth used for boat wiring.

 

[Refueler]

Seriously, "There are cable joins, mostly soldered, all over our boat" which boats do you know of (in the thousands) where most of the cable joins are soldered.

I'd like to know, because i've never, ever, seen such a thing on any boat i've worked on. In fact, it's rare to find any joins soldered.

Quite a few panels have cables soldered to the switches / components .... VHF's with centre core soldered into the PL259 .... multi-pin connectors soldered in factory for various gear ...

I admit that cable to cable is rare ... but does occur ...

 

[PaulRainbow]

Quite a few panels have cables soldered to the switches / components .... VHF's with centre core soldered into the PL259 .... multi-pin connectors soldered in factory for various gear ...

I admit that cable to cable is rare ... but does occur ...

But hardly "cable joins, mostly soldered, all over our boat", "Like thousands of other boats".

 

[Elessar]

While YouTube is awash with soldering vids - I can't find any help with something I'd have thought would be common.

If I run a 12v cable aft, then want to split it between (for example) port and starboard nav lights, how do I make the connection? To test, I've done it with Wago connectors, but I believe only soldering and heat-shrinking is a robust solution for marine environment. Yes I can solder three together (very messily!) But then you can't get a heat shrink over!

I'm sure this is really simple, but I need advice please!

Don't solder joints on a boat. My boat is like Paul's in has none. Shrink wrap crimps with glue in are the best. Even underwater.

 

[Elessar]

Er, all of them!!


OK - that would make life easier! I assume I should still tin the ends of the wires where they join the connectors?

all of them Seriously? They will fail. One at a time.........

 

[Elessar]

this is what you should use to join wires on a boat if you never want to worry about the joint again. You need the proper tool too.

Heat Shrink Crimp Butt Connector (Clear, Red, Blue, Yellow)

 

[Refueler]

this is what you should use to join wires on a boat if you never want to worry about the joint again. You need the proper tool too.

Heat Shrink Crimp Butt Connector (Clear, Red, Blue, Yellow)

Not to be confused with the totally useless low temp solder type that you often see advertised.

 

[Elessar]

Not to be confused with the totally useless low temp solder type that you often see advertised.

absolutely correct! Some kits have both in.

 

[Refueler]

absolutely correct! Some kits have both in.

I decided to buy a box of assorted sized Low Temp Solder verion ..... after the 4th failed on a simple test run in the workshop - the box has been put to the back of the drawer ..... great idea - but totally useless. I didn't even need to pull on the joint - they just fell apart ....

 

[Beelzebub]

Seriously, "There are cable joins, mostly soldered, all over our boat" which boats do you know of (in the thousands) where most of the cable joins are soldered.

I'd like to know, because i've never, ever, seen such a thing on any boat i've worked on. In fact, it's rare to find any joins soldered.

I once came across a Nelson 42 where just about everything behind the dash had been soldered!

 

[KompetentKrew]

Anyone remember the 'Scotch press' connectors ?? Car Audio people and various loved those .... blue plastic bodies with blade inside that when you inserted the wires and pressed the connector closed - the blade cut into the insulation through to the wire itself.
I never trusted them years ago - but later saw gear that had been connected with them many years before and still surviving pretty harsh environment ..

Think I have some of those on my boat.

Is this what you mean?

 

[PaulRainbow]

Think I have some of those on my boat.

Is this what you mean?

Yes, nasty things.

 

[ylop]

Yes, nasty things.

I once went to view a rib for a friend of mine who was a few hours drive away, and wanted to see if it was worth travelling to look at properly. The wiring used an “interesting” approach of tapping into the main battery cables: Radio, Fishfinder, Nav Lights, Bilge Pump all connected to the main engine to battery cable with separate self tapping screws through the insulation. When I questioned the owner it had been like that when he bought it and never had any issues!

He didn’t buy it - although I think that might be more do with the state of the trailer than the electrics!

 

[thinwater]

I decided to buy a box of assorted sized Low Temp Solder verion ..... after the 4th failed on a simple test run in the workshop - the box has been put to the back of the drawer ..... great idea - but totally useless. I didn't even need to pull on the joint - they just fell apart ....

I bought two types. I was asked to test them.

One from Amazon. Horrible. Threw them away fast.

The other from 3M. Better. But I also threw them away so that I would not be tempted to use them.

It's just impossible to make solder that melts low enough, but high enough not to melt at high load, and heat it through the heat shrink (which insulates against the heat gun) without destroying the heat shrink.

It just does not make sense on the face of it. If super-low-melting solder was a good idea we would use it. It is a bad idea. Obviously.

---

I'm not a hard-liner against solder. I do, once in a rare while, always very small wires and sometimes because of space problems or because the wire must be soldered to a lug. But never for ordinary (22 AWG to big) connections. No point.

 

[Refueler]

I bought two types. I was asked to test them.

One from Amazon. Horrible. Threw them away fast.

The other from 3M. Better. But I also threw them away so that I would not be tempted to use them.

It's just impossible to make solder that melts low enough, but high enough not to melt at high load, and heat it through the heat shrink (which insulates against the heat gun) without destroying the heat shrink.

It just does not make sense on the face of it. If super-low-melting solder was a good idea we would use it. It is a bad idea. Obviously.

---

I'm not a hard-liner against solder. I do, once in a rare while, always very small wires and sometimes because of space problems or because the wire must be soldered to a lug. But never for ordinary (22 AWG to big) connections. No point.

You should check out what we have to connect on some models .... take an XT90 connector and solder a serious battery lead to it ... or bullet connectors from 2mm to over 5mm .....

Passing loads of 10A to 100A or more ...

We never see heat build up and subsequent failure of the solder joint ......

 

[Refueler]

Think I have some of those on my boat.

Is this what you mean?

Yes ... but was thinking more of the splicing in of another wire to an existing one ... common on car audio ... you have a lead connecting two items ... then you want to connect a second into the same lead .. the 'Scotchblock' allowed the uncut original lead to have the extra lead placed next to it and then block closed .. the blade cutting into the insulation of both and joining.

 

[Refueler]

I once went to view a rib for a friend of mine who was a few hours drive away, and wanted to see if it was worth travelling to look at properly. The wiring used an “interesting” approach of tapping into the main battery cables: Radio, Fishfinder, Nav Lights, Bilge Pump all connected to the main engine to battery cable with separate self tapping screws through the insulation. When I questioned the owner it had been like that when he bought it and never had any issues!

He didn’t buy it - although I think that might be more do with the state of the trailer than the electrics!

The practice of pins or screws through large cables is not such a far fetched matter ... Its been used to create a 'Bus Bar' in fact .. the large diamter cable acting as the bus bar plate ...

Do not get me wrong - I would not use such tactic ... but it was used in years gone by.

 

[ylop]

The practice of pins or screws through large cables is not such a far fetched matter ... Its been used to create a 'Bus Bar' in fact .. the large diamter cable acting as the bus bar plate ...

Do not get me wrong - I would not use such tactic ... but it was used in years gone by.

from a pure physics point of view it clearly works - in the damp jockey console of a rib next to the spare fuel… maybe not the ideal spot for improvised electrics!

 

[PaulRainbow]

Yes ... but was thinking more of the splicing in of another wire to an existing one ... common on car audio ... you have a lead connecting two items ... then you want to connect a second into the same lead .. the 'Scotchblock' allowed the uncut original lead to have the extra lead placed next to it and then block closed .. the blade cutting into the insulation of both and joining.

Look closer Nigel, the ones in the picture are exactly what you describe.