Why butt connections are not a good idea in an exposed environment.

[JDCAVE]

A picture worth 1,000 words.

 

[boomerang]

whew! I think you've squeezed all of the life out of that connection that you could. It looks like a fairly substantial 6 or 4 gauge wire. What was it for?

 

[caltexflanc]

Unprotected and unsupported butt connections that is.

 

[KnotYet]

If done properly, it will hold up as well as any terminal.
Still, a pair of ring terminals and a terminal strip is nice.

 

[twistedtree]

What that in heat shrink, or exposed?

 

[boatpoker]

One can of T-9 is worth a million corroded butt connectors

 

[JDCAVE]

Yes. It’s the 6 gauge for the engine, and was enclosed in heat shrink. It looked well done, but for part of its life it was inside the false bottom of the skiff. Now connected only at the engine and at the shutoff switch. Cable protected in split weave.

 

[twistedtree]

Yes. It’s the 6 gauge for the engine, and was enclosed in heat shrink. It looked well done, but for part of its life it was inside the false bottom of the skiff. Now connected only at the engine and at the shutoff switch. Cable protected in split weave.

So actually submerged?


Heat shrink obviously helps protect connections, and it's really interesting to see just how much or how little.

 

[psneeld]

Heat shrink comes with and without adhesive.

I believe the adhesive with uniform squeeze out is superior...but I hff ave no proof....just reason.

 

[twistedtree]

Heat shrink comes with and without adhesive.

I believe the adhesive with uniform squeeze out is superior...but I hff ave no proof....just reason.

Yes, I think that's correct.

 

[rslifkin]

With tinned wire, good quality adhesive heat shrink and preferably not being submerged, a butt connector should last a very long time. Skip one of the protection factors and get it wet frequently, then all bets are off.

 

[Arc]

It simply wasn’t done right. Don’t blame the connector.

 

[JDCAVE]

I didn’t do this connection. Here is a better photo. You can see that the wire inside the connection was completely gone. The flexible wire to the engine was a brand called “Seiwa”. I’m not certain if it was tinned or not. Obviously it wasn’t long enough. Replaced it with regular tinned 6 gauge all the way to the switch (+) and to the battery (-) with no butt connectors.



Jim

 

[RT Firefly]

 

[Larry M]

Yikes! But with that laying in water/very moist environment with 12 volts even intermittently going through it, I’m not surprised.

 

[ksanders]

While butt connectors are not my preference...they are used by electrical professionals every day in a variety of conditions both dry and submerged.

Think about high voltage power lines.

When a line faults, they do not replace the whole line, they install a splice in the line. On buried cables they bury the splice never to think about it again.

The one in the photo represents a failed splice due to either latent corrosion in the original wire, or failure of the splice to seal properly.

It is not indicative of butt connections in general.

 

[angus99]

Yikes! But with that laying in water/very moist environment with 12 volts even intermittently going through it, I’m not surprised.

Like that avatar, Larry!

 

[Tiffany]

A touch of dialectric grease keeps corrosion away from open surfaces, or as others suggest, spray with Boeshield T9.

 

[caltexflanc]

I just want to reinforce that it is essential that there are physical hold downs on either side of the connection, so it is not subject to motion. If it was loose on the bottom of a bilge, not good.

 

[rolomart3]

I didn’t do this connection. Here is a better photo. You can see that the wire inside the connection was completely gone. The flexible wire to the engine was a brand called “Seiwa”. I’m not certain if it was tinned or not. Obviously it wasn’t long enough. Replaced it with regular tinned 6 gauge all the way to the switch (+) and to the battery (-) with no butt connectors.

View attachment 102522

Jim

Based on the picture provided, I would not blame the butt connector. The copper inside the connector rusted from humidity as expected.

Here are some engineering facts to keep ib mind:
1. Wire is stranded in order to allow flexing it without weakening it at the flexing point.
2. Copper corrodes in humid environments but the corrosion forms a protective coating like the case of stainless steel. However, this coating cracks and becomes permeable with excessive vibration or flexing of the wire.
3. Only tinned-stranded copper wire has the corrosion and mechanical-stress resistance required for long term service in the marine environment.

Conclusion: use tinned stranded wire anywhere to repace it would be a major hassle.

 

[Rich wilmer]

Butt splice will last longer than a terminal strip if properly installed self sealing heat shrink and silver paste,and thats a fact jack

 

[DarrenCharles]

Old timers said solder the connection. I understand there are pros and cons. I just started using wire nuts instead of butt connectors. I thorougly, but carefully, coat the twist with dialectic grease before installing the wire nut, being careful to barely extend the grease onto the insulation. I then secure the connection to minimize vibration, then I coat the end of the wire nut with 100% silicone caulk. It seems like I obtain a better moisture resistant connection than heat shrink butt connectors (and definitely better than non-heat shrink). Time will tell.

 

[Steve DAntonio]

Heat shrink comes with and without adhesive.

I believe the adhesive with uniform squeeze out is superior...but I hff ave no proof....just reason.

I do, I've used adhesive HS in wet location's countless times, with no water related failures, the adhesive makes for a water-proof connection, the non-adhesive version is simply insulation.

Running wires, much less connections, below normal bilge water level is a violation of those pesky ABYC Standards.

You say, "for the engine", what exactly is is for?

 

[Barking Sands]

Darren if you are going to use wire nuts...look into the wire nuts used for low voltage landscaping. They are meant to be openly buried in the ground and come with grease installed plus a little skirt to contain it.

However..I dont really recommend wire nuts in a boat. Maybe if you zip tied the wires together plus electrical tape.

I just repaired two terminal ends on my little trawler that had failed at the crimp. They were glowing and melting the terminal plastic and wire near the terminal ends. A combo of a poor crimp plus corrosion cause too much resistance. I was looking for the source of the electric smell for two days...then my wife caught a glimpse of the glow in the right light conditions in the electrical closet and pointed it out. I was glad she saw it. Easy enough repair once found but having electric smell that you cant find is not a good feeling...lol. Funny thing is these crimps were aftermarket crimps when someone added a hotwater heater. The remaining original Taiwanese crimps all still look pretty good.

 

[Traderjoe]

A picture worth 1,000 words.

View attachment 102509

So what is better?

 

[BrianSmith]

One can of T-9 is worth a million corroded butt connectors

I'm curious how you use T-9 to help connections last longer. As simply as squirting it on when the connection is finished, or is there more to it?

 

[Deano]

I use T-9 on the connection prior to shrinking the heat shrink. I let it air for a bit before applying the shrink tube.

 

[Frosty]

I use T-9 on the connection prior to shrinking the heat shrink. I let it air for a bit before applying the shrink tube.

Since T-9 is supposed to leave a waxy film (on purpose), wouldn't that potentially interfere with the adhesion of the adhesive in the heat shrink? Or are you using non-adhesive heat shrink?

******

I use good quality crimpers, tinned wire, and adhesive heat shrink -- no complaints so far, although I don't have any connections in bilge water spaces.

I like the idea and function of power posts and terminal blocks (and do use them in certain situations), but then I always think, hmm, exposed connections vs nestled cozily in adhesive heat shrink.... (of course terminal blocks and power posts do fit certain situations better regardless).

I do try to leave some extra wire when I make butt splices so that if necessary to change or re-do it's there.

 

[KnotYet]

A lot of electrical connections practice is done based on what works for someone.

For example, I would never use a wire nut anywhere on any vehicle.
Not because it can't be made to work but because to me there are better alternatives.

I also paint a bit of Kopr-Shield paste on each bare wire end before crimping with a
ratcheting-type pro crimping tool. Then I tug the fresh connection just to make sure.
Then I apply the heat shrink. Nerd Alert: I have a Dymo Rhino label maker that also
can print a label directly on their heat shrink tubing. Handy for complex rewiring jobs.

It's a good idea to use a terminal strip to connect anything that may get removed or
replaced that comes with a wire lead, i.e. bilge pumps, fans and so forth.

 

[thataway]

ABYC standards are for a very good reason:

"Twist on connectors, i.e., wire nuts, shall not be used.” 11.16.3.6.

If you have a survey on your boat--one of the first "dings" will be wire nuts. Silicon externally is not a good sealant on wire...

Certainly no connector should be left submerged in water (salt or fresh) in the bilge. However a marine quality grade of tinned wire, and a quality adhesive lined heat shrink, with a proper crimp is the best that is available. If there is any question about vibration or support--and the wire cannot be supported, another layer of shrink wrap over the first is the best substitute.