Butt Splicing from Battery to Engine??

[wingssail]

Butt connectors are a source of problems. I've used them extensively for almost all the wiring on my boat for 33 years and I can attest that electrical failures are often traced back to an improper or failing butt connection. What is worse is that I don't always use sealable connectors or cover them with tape, so a corrosion issue can happen, and has.

That being said, there must be hundreds of butt connectors and problems for me have been rare. I'll keep using them because of the convenience and deal with the problems when they occur. At least when a problem occurs you have a likely suspect (the nearest butt connector) to start with when diagnosing the problem.

NOW, two problems with the wire mentioned by the OP, in my opinion.

1. High amperage loads should not go through butt connectors. Battery cables carrying starting or charging loads need properly installed cable terminators (lugs) which can be bolted on at either end. These may be soldered or crimped or both. I no longer solder them because the solder may mask a poor crimping job, and when the connection gets hot it may fail.

2. I do not recommend any wires going directly from the engine, or any electrical device, to the battery, fuse or not. I know that many manufacturers and installers recommend this, it is mostly to insure that their device gets a good source of power. I think that all wires should go through the switch panel with a breaker so that you can turn it off. All power supplied to the breaker should go through a battery switch so that you can a) cut the power to every thing and b) you can switch to another battery bank if needed. If you are careful with your connections and use properly sized wires the loses are manageable. This also avoids the big pie-up of connections at the positive battery terminal. I have one wire on the battery, it goes to the battery switch.

[Stu Jackson]

Originally Posted by wingless

According to the OP there is a breaker "coming off the battery" and this is for the engine.

WADR, on a diesel engine could you please explain what "this is for the engine..." means?


There is the starter.


There is the alternator output.


Could the OP be clearer than battery to engine?


What on "the engine?"



Engines do NOT "get" connected to batteries.


Butt connectors can easily be replaced with PowerPost fittings and lugs.


He said he had a new engine put in. Was this part of that work?

[Q Xopa]

Originally Posted by john61ct

No, if the crimp is done correctly

quality wire fittings & tools, cold-welded gas-tight would pass a milspec pull test,

then adding solder contributes nothing good.

Not saying a good solder-only connection can't be nearly as good, but takes a much higher level of skill to do those consistently reliably.

Im sure I wont convince die hard solderers. Crimping, with good crimpers only, not soldering is the recommended method for a number of reasons.

Either takes 'skill'. In fact there are more factors to consider to get a good crimp.

[john61ct]

If all the factors are there, no skill is needed in actually executing the crimp, could easily train a monkey to get perfect results 100% of the time all day long.

All the knowledge and skills for crimping is built into the tools & materials selection.

[Q Xopa]

Originally Posted by Q Xopa

Im sure I wont convince die hard solderers. Crimping, with good crimpers only, not soldering is the recommended method for a number of reasons.

Either takes 'skill'. In fact there are more factors to consider to get a good crimp.

'If' you have all those things ready. That is exactly the bulk of the skill required. Ie knowing which tools and crimps are required. Most boats I have seen dont have the right crimpers, crimps. Most boat owners are blissfully unaware with what they dont have.

Saying a monkey can do a good crimp says to me how simple you think it is. I do aircraft crimps regularly. Once you know they are not so difficult. But there is far more to know that you could teach a monkey. Avionics guys are the highest paid in a hanger for their skill. Crimping is a far greater proprtion of their job. For example they have to be 'calibrated' with go no go pins etc.
Sure you can do them monkey style with your Autopro crimpers and crimps. I guess we know how you will do yours, one day perhaps. Carry on.

[Mike Banks]

I have made many such connections, but I use a solder-in connector. If you do not have one you can make one for the job from copper pipe. Put two lengths of heat shrink tubing of different sizes capable of covering the tube over one of the cables first and slide them away from the area to be heated.

I split the tube myself using a Dremel tool, sometimes one has to remove a strip of copper from the tube to get a snug fit. Clean and tin the inside of the copper trough you now have made, using resin cored solder.

Lay the wires into the trough and close it over the cable ends, cleaned and tinned copper trough over the cable ends. Heat it with a propane flame and run in more tinned solder until the tube and cable ends are fully wetted. Allow to cool. Slide the inner tube of heat shrink tube over the splice, warm it using a hot air blower (or propane flame if you are careful. Now slide the next piece of heat-shrink tubing over the splice and shrink that one down too. Tape over the whole using Nitto tape or something as robust.

[wingless]

Originally Posted by Mike Banks

Slide the inner tube of heat shrink tube over the splice, warm it using a hot air blower (or propane flame if you are careful. Now slide the next piece of heat-shrink tubing over the splice and shrink that one down too.

For a long time I was using a small butane torch for heat shrink tubing.

Now I use this Master Varitemp VT-750CK heat gun w/ the A-160-HG curved heat shrink deflector, part of the 35245 deflector kit.

The Master heat gun does a great job.

There have been instances where having a powerful heat gun is handy.

[john61ct]

Originally Posted by Q Xopa

Autopro crimpers and crimps.

My set of crimping related tools would cost over $4000 if bought new, several purchased from MS, only use UL 105° boat wire, and terminal / fittings from a very limited list of top vendors.

I do not consider anything related to this, to come under what I was referring to as skills.

My point is that knowledge and gear ensures repeatable crimping success, whereas doing the same with solder requires time, practice, technique. Some pick it up quickly, some never get it right.

[thinwater]

4 is 70#, 5 is 60#, 1 is 100# (E-11, connectors, unless this is the wrong reference, which is possible.)


Wire Gauge (AWG) ABYC E-11 UL 486A (crimp)
UL 486A (wire nut or plate)
24 N/A 5 5 22 N/A 8 8 20 N/A 13 10 18 10 20 10 16 15 30 15 14 30 50 25 12 35 70 35 10 40 80 40 8 45 90 45 6 50 100 50

[jimbunyard]

Originally Posted by Mike Banks

I have made many such connections, but I use a solder-in connector. If you do not have one you can make one for the job from copper pipe. Put two lengths of heat shrink tubing of different sizes capable of covering the tube over one of the cables first and slide them away from the area to be heated.

I split the tube myself using a Dremel tool, sometimes one has to remove a strip of copper from the tube to get a snug fit. Clean and tin the inside of the copper trough you now have made, using resin cored solder.

Lay the wires into the trough and close it over the cable ends, cleaned and tinned copper trough over the cable ends. Heat it with a propane flame and run in more tinned solder until the tube and cable ends are fully wetted. Allow to cool. Slide the inner tube of heat shrink tube over the splice, warm it using a hot air blower (or propane flame if you are careful. Now slide the next piece of heat-shrink tubing over the splice and shrink that one down too. Tape over the whole using Nitto tape or something as robust.

Not a criticism, as I use a butt splice method that I'm sure most here would label cowboyish, and won't disclose it to save hassle (though I've used it for decades and never had a failure), but I'm pretty sure that the method you describe, if it matters to you, doesn't meet AYBC guidelines, which I think require soldered connections to be crimped as well.


Since I've not commented on the 'solder question' in a few years, I'll offer a few considerations, in no particular order.

Airplanes and aerospace vehicles are not boats and cars. The differences in environment alone make any comparison almost moot; throw in the inspection and (I assume) certification requirements for aircraft and most comparisons are entirely moot.

Both soldering and crimping are not 'monkey-trainable', not because they can't be (pretty much) learned by rote, but because determining if the results are acceptable cannot. I.e the skill comes in when inspecting either type connection .

I always use both crimping and soldering, and can recall no failures in well executed connections. When soldering in less than ideal conditions (blackened wires, old oxidized terminals etc. [which I would use only for personal projects or in extenuating circumstances]), proper preparation can yield serviceable connections, but they are always considered temporary. Though generally they are superior to 'average' crimped connections, in longevity and conductiveness.

In my experience and opinion, crimped-only connections are prone to failure eventually. While a 'gas tight' crimp will be good for a time, even a substantial time, eventually, heating and cooling of the crimp, and differential expansion caused by the difference between stranded wire and solid terminal barrel walls will allow moisture in and with it, corrosion will inevitably form.

I have innumerable instances of this happening, in manufacturer-supplied equipment (if the manufacturer can't make a 'proper' crimp, who can?) and sizes ranging from 20 gauge wire to 4/0 cable.

I've had some luck avoiding corrosion in crimp-only connections by dipping the wire into a corrosion inhibitor before crimping.

Certainly, knowing what one's doing is the key to making successful, long-lasting electrical connections. Neither crimping nor soldering is particularly difficult, but like anything else, technique and practice are what is required.

A well-rounded boatwright should have both techniques in his repertoire...

[Bycrick]

By comparison to a properly made copper crimp, solder is a very poor conductor. Only about 11% as conductive as copper. This doesn’t bode well for a high-current connection.

[jimbunyard]

Just for grins then...I've one word for you to ponder; dielectric.

[Bycrick]

A dielectric is an insulator.

[jimbunyard]

Think harder...

[thinwater]

Originally Posted by jimbunyard

Think harder...

Or write more clearly. The first requirement of good written communication is that it be clear and unambiguous. I'm sure we can all think of several uses for the word in the context of a discussion of electrical connections.


If we are to consider only one word, Webster's says this:
Definition of dielectric



: a nonconductor of direct electric current