Heat Shrink vs Insulated Terminals

[Sailing48N]

I've been trying to wrap my head around our boats electrical system as a whole to see what my future plans will be for upgrades to various electrical components. The more I learn the more questions I have. 

When do you choose heat shrink vs insulated terminals on our boats?
What's best to use behind the main house panel?

I'm assuming that you would want to use adhesive heat shrink terminals/connectors anywhere where there is likely to be contact with water like the bilge pump electrical connections.

Behind our house electrical panel all I see is what appears to be insulated connectors. I do plan on replacing my electrical panel in the future but that's not in the budget this year. I would like to clean some things up and redo a few of the connectors back there as well as some of the connectors in other places throughout the boat when I find something that needs attention.

I've been reading up as much as possible on Mainesails website and on these forums about proper crimping tools, connectors, etc. So, my question isn't so much as HOW to use each type of connector but more about WHEN is it appropriate to use each type. I haven't found that specific information in my reading/research thus far.

[KWKloeber]

 Russ,

IMO  the  only reason to use nylon  insulated (double crimp) terminals versus adhesive heat shrink (AHS) terminals, is time and cost. Obviously the time involved in heat shrinking the terminals and that the AHS are more expensive.

IMO  double crimp terminals have no place on any application where there's moisture and chance of corrosion. Even if they have heat shrink tubing over them, the end of the terminal is open and thus corrosion can creep into the crimp and wire.

Additionally, the insulation capture, and strain relief is inferior on the double crimp, compared to AHS.
   YBYC, but If you're asking an opinion, "don't use them."   JTSO   

On my panel, many of the double crimp terminals were loose and obviously made poor connection. You can take your AHS crimper and make sure the wire crimper is tight.  Best to replace them as you have time and budget.

Ken

[KWKloeber]

I should add the only time to use non-AHS is as RC shows  on his website  --  when crimping small gauge wire and using open terminals. You don't have a choice.

kk

[Stu Jackson]

One important hing to consider on our boats, which, admittedly, Ken is not specifically familiar with:  just above the electrical panels is the stanchion with the waste tank vent.

While the area behind my panel is dry, dry, dry, I have seen some that look as if a fire hose had been squirted into it.

That said, for what you are doing now, ITWMB, I wouldn't bother to heat shrink each connection.  IIRC, all my terminals are facing down, with the wire going UP to them.  My larger issue is that they didn't use ring terminals, but flanged spade connectors!

This should get you by until you decide what you want to do when you replace your panel next year.  The wiki has some very good illustrations of what, for example, Jon did with his.  A great writeup with tons of pictures.

[KWKloeber]

 Hey Stu,

Actually, I had followed that thread and  aware of  that issue with the stanchion. But  in my way of thinking, I thought that was kind of irrelevant because I think anywhere there's a chance for elevated moisture (i.e., boat equals water equals elevated moisture, salt equals worse) there's no place for double crimp terminals. But, that's opinion not fact.   In other words OMB, I use AHS  whether it's a wet bilge, or behind a dry panel (especially because it's out of sight out of mind forever.)

Clearly seaward cheaped out with double crimp fork terminals, And I don't believe there are even the captive type fork terminals

KK

[mainesail]

On my own vessel, and my "I want the best" customers boats, I use all heat shrink terminals.  For customers who are into saving money I use mostly AMP & occasionally Molex, three piece double crimp terminals. The double crimp terminals many builders used in the past are pretty poor quality.

That said if proper crimp tooling is used, tooling that can meet at least UL but preferably Mil-Spec, no moisture is getting past the crimp band. If you use poor quality tools moisture can sneak by and corrosion can set in. I have a slew of older 1970's Sabres I work on, about 24 of them at last count, and the factory double crimps, for the most part, were actually executed quite well. Most of them are still going strong 34 -38+ years later..... 

Production builders pretty much use double crimp terminals to save money. Buy a Morris etc. and you'll get heat shrink terminals...

[Bill Shreeves]

Sounds like AHS is the best way to go.  Is there a particular brand that you guys favor and possibly a place to go for a fair price?  I haven't tackled all the electrical work that I know I need to do and frankly, a newbie @ 12 volt systems but have done some reading.

[Jon W]

I used the AHS ring and butt connectors from Ken on this forum. A good price, quick shipping, and I think better than what I got at West Marine. I don't remember the brand.

Ken are they FTZ?

[Braxton]

We really need to entitle threads like this:.  "Hey Braxton, you're doing it wrong".

I apologise for my ignorance here.  I totally get the whole heat shrink tubing part of this.   The fundamental piece that I am missing is what is the actual joint inside the tubing.     How is that being done?

[KWKloeber]

Hey Braxton, I'm confused.  What do you mean "the whole HST thing?"   
What would you be using adhesive heat shrink tubing on? (typically making up battery cables or smaller cables using lugs and covering the lug crimp.)  Maybe if you clarify the question or give an example?

I prefer FTZ brand AHS and uninsulated lugs/terminals. I think they're better than Ancor brand, but that's subjective.  Ancor is a close second.

ken

We really need to entitle threads like this:.  "Hey Braxton, you're doing it wrong".

I apologise for my ignorance here.  I totally get the whole heat shrink tubing part of this.   The fundamental piece that I am missing is what is the actual joint inside the tubing.     How is that being done?

[Braxton]

When I replaced my bilge pump I wired it up using heat shrink butt connectors along these lines:

https://www.westmarine.com/buy/ancor--heat-shrink-butt-connectors--P009_275_004_003?recordNum=87

I gather instead I should be using this:   

https://www.westmarine.com/buy/ancor--adhesive-lined-heat-shrink-tubing-alt--P009_275_003_003?recordNum=1

with the connection made inside of it.   What am I using to make the connection?   Is it a simple butt connector like this:

https://www.westmarine.com/buy/ancor--22-18-nylon-double-crimp-butt-connectors--16899767?recordNum=38

[mainesail]

When I replaced my bilge pump I wired it up using heat shrink butt connectors along these lines:

https://www.westmarine.com/buy/ancor--heat-shrink-butt-connectors--P009_275_004_003?recordNum=87

The linked butt splices above are the correct product for the bilge pump. I am assuming you used a tool designed for use on this type of terminal and you did not void or rip the shrinkable insulation.

[Braxton]

So then when do I use the heat shrink tubing?

[KWKloeber]

Brax

You would use the AHS tubing if you used uninsulated terminals. Or as I said last on the end of the cable if you were crimping a battery lug on s cable. Or sometimes I use an uninsulated lug for some applications instead of a heat shrink terminal.

Also I use AHST to reinforce the strain relief if the conductor is subject to flex at the terminal.

I use a belt/suspenders on my bilge. AHS butts with AHS tubing over (extended beyond the butts.)

ken

[Braxton]

OK, I think I've got it.   It's nice to know I was doing it completely wrong.

Thanks.