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Heat shrink/non heat shrink crimps

nohoflyer

Well Known Member
Patron
Ok I’m doing the wiring education on myself and am wondering if heat shrink is the way to go on all butt connectors?

I’m starting with the Dynon probe specifically but this question is general in nature.
 
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I have used them on my most recent project and really like them. They seem to give a very good mechanical bond and prevent the wire to be weak where the wire insulation ends.
 
Amp insulated butt splices with the correct tools, no need for heat shrink, of course it won't hurt if you feel compelled.
 
You should avoid splices as much as possible...but if there's no escape, AS81824 (M81824) environmental butt splices installed with the right tool (GMT232) is the only way I'd do it.

Number and document the splice on your wiring diagram, too--future troubleshooters will be very grateful.
 
There are times when a good old "Western Union" splice and a piece of heat-shrink is the way to go. But, most of the time the Raychem "environmental" splices work great. They come in 2 flavors, tin-plated, and nickel-plated.

I haven't used the MS25181 "window" type butt splice since the mid '80s, when the Navy ditched them in favor of the Raychem splices. And, I'd never use the automotive "crimp" splices that seem to get crimped with just whatever tool happens to be handy.

The tin-plated Raychems are quite a bit cheaper than the nickel plated ones. And, I've had good results with them. You absolutely must use the proper crimper though. The GMT-232 @irgabriel mentioned is the right tool to use.

And, a proper heat gun with give you a clean heat-shrink sleeve that is sealed at both ends. I have used a lighter in a pinch. But, I think a good heat gun is not that expensive, gives much more consistently better results. And, it has several other uses.

https://www.aircraftspruce.com/catalog/elpages/d-436raychem.php

https://www.aircraftspruce.com/catalog/topages/crimptoolgm232.php
 
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Ok I’m doing the wiring education on myself and am wondering if heat shrink is the way to go on all butt connectors?

I’m starting with the Dynon probe specifically but this question is general in nature.

Ancor (and others) make crimp connectors with built-in adhesive heat shrink for marine use. You'll be hard pressed to find a more brutal environment for electrical connections ;) One source: https://www.westmarine.com/buy/anco...AW2N3NlUSyAncw6B_hujgSXFXlqHc0AAaAo7BEALw_wcB
 
There are times when a good old "Western Union" splice and a piece of heat-shrink is the way to go. But, most of the time the Raychem "environmental" splices work great. They come in 2 flavors, tin-plated, and nickel-plated.

I haven't used the MS25181 "window" type butt splice since the mid '80s, when the Navy ditched them in favor of the Raychem splices. And, I'd never use the automotive "crimp" splices that seem to get crimped with just whatever tool happens to be handy.

The tin-plated Raychems are quite a bit cheaper than the nickel plated ones. And, I've had good results with them. You absolutely must use the proper crimper though. The GMT-232 @irgabriel mentioned is the right tool to use.

And, a proper heat gun with give you a clean heat-shrink sleeve that is sealed at both ends. I have used a lighter in a pinch. But, I think a good heat gun is not that expensive, gives much more consistently better results. And, it has several other uses.

https://www.aircraftspruce.com/catalog/elpages/d-436raychem.php

https://www.aircraftspruce.com/catalog/topages/crimptoolgm232.php

That crimping tool is 233.00. Wow.
 
Ancor (and others) make crimp connectors with built-in adhesive heat shrink for marine use.

At $5 each? My goodness...

Here's a link to uninsulated brazed barrel butt connectors, at $5 per hundred:

https://www.waytekwire.com/item/30260/Molex-19215-0009-Standard-Butt-Connector-/

Another $5 or so will buy 8 feet of adhesive lined 3-to-1 heat shrink:

https://www.waytekwire.com/item/22203/DSG-Canusa-CPA-100-3-16-BLACK-Polyolefin-Dual-Wall/

Break.

My personal preference is a bare terminal and adhesive heat shrink. Mechanically, the finished installation is hard to beat by any measure. However, it does burn time, thus Amp terminals are the practical choice when time equals money.
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That crimping tool is 233.00. Wow.

I use a Wirefy kit (Amazon)...multiple different crimp inserts for $75, but you can get it with just a heat-shrink butt crimper for $23. My only complaint is that that tool is too fat for crimping Molex mini-pins so I had to buy a skinnier one for those (iWiss). I've bought most of my connectors from Spruce, Stein, or Amazon.

These tools from Amazon are accurate and work great. How they stand up over time is my key question, but I'm confident that they'll be fine for the occasional use I put them to. I love good quality tools as much as the next guy but as an amateur, I can't imagine paying $233 for a specialty tool I'm going to use as little as I do.
 
For one (at least!), I'm with Dan on this subject. Good quality bare crimp connectors (from Wayek or Digi-key) and adhesive heat shrink on each. Heat gun with a wrap around heat spreader to seal them up, and these things are bulletproof! They are good enough to hold up on my fishing boat, salt water and all.

The all in one Amcor splices with a correct crimper are great for a production environment, or one that carries third party liability, but it seems to be overkill for a careful builder.

Just my 2 cents, works good for me
 
I go by the theory that you only have to secure (heat shrink) the ones you don't want to have come loose or break. It's your airplane.
Kinda like the dentist says to do I really have to floss and brush my teeth. "You only have to clean the ones you want to keep."""
I like secure and YES it takes longer, But, bare connectors and heat shrink are really not that hard to get right.
I've had wires break in flight, Because somebody before me did not practice good work ethic.
My three cents worth Art
 
That crimping tool is 233.00. Wow.

Yup. And, you need specific crimpers for coax, and some different crimpers for PIDG terminals. And, then there's the crimpers for the pins that go in D-Sub connectors. There are different sizes of wires and pins. And some crimpers only do one size. Then, there's even more expensive ones that do all different sizes.

Aviation ain't cheap. But after 22 years is the Navy as an avionics tech and another 4 years in a part 145 repair depot, I'm not gonna trust crimp splices/terminals/pins that aren't done with the correct tool.
 
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In my airline career Boeing/Douglas spec’d std Amp terminals for 90% of connections, engines/pylon req’d sealed splices.

Making folks feel like if they don't environmentally seal all their connections, they are somehow doing substandard work is incorrect.
I suggest folks stick to mil-spec parts.

$233 for crimpers is super cheap compared to most crimpers, below is my go-to for most crimps, and it’s the same tool I used in the airline.
(I have thousands invested in wiring tools but many can be found at used sellers for less, good tools=good connections )

https://www.newark.com/amp-te-connectivity/59250/crimp-tool-pidg-strato-therm-plasti/dp/50F546?gclid=EAIaIQobChMIruTFlonR9wIVv2pvBB2o7QUuEAQYAiABEgJ4lfD_BwE&mckv=_dc%7Cpcrid%7C578406215036%7Cplid%7C%7Ckword%7C%7Cmatch%7C%7Cslid%7C%7Cproduct%7C50F546%7Cpgrid%7C133263230112%7Cptaid%7Cpla-1598254952066%7C&CMP=KNC-GUSA-GEN-Shopping-Smart-Low-ROAS
 
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Making folks feel like if they don't environmentally seal all their connections, they are somehow doing substandard work is incorrect.

Re adhesive heat shrink, I don't think the primary intent is environmental sealing. A butt splice can be sealed. Fast-on and ring terminals often remain open at the terminal end.

As noted previously, the nod goes to the Amp terminal when speed counts, and when installed using a quality crimper, they are remarkably consistent.

I use a specific ratcheting crimper for bare terminals, in order to achieve a similar level of consistency at the wire crimp.

I would argue a terminal using adhesive heat shrink for strain relief offers superior fatigue resistance. That said, one could easily argue the improvement is overkill.

$233 for crimpers is super cheap compared to most crimpers, below is my go-to for most crimps, and it’s the same tool I used in the airline.

Lemme run a thought up the pole here. Although the Vans community tends to be above average in terms of buying power, let's not forget a fundamental fact...EAB continues to be about making aviation affordable. Out goal should be to show builders how they can build quality into their process, regardless of the financial commitment.

Put another way, I would not propose bare terminals and heat shrink as a new standard. I do offer them as an alternative, one which offers installed quality equal to the certified approach.
 
Making folks feel like if they don't environmentally seal all their connections, they are somehow doing substandard work is incorrect.
I suggest folks stick to mil-spec parts.

I like the Raychem enviro splices because they are a lot skinnier than the "window" type butt splices. The fact that they're sealed on the ends is a nice plus.


I bought mine at Boeing Surplus years ago. My employer, at the time, "calibrated" them for me for free. Anyone whose crimping PIDG and the Amp "window" style butt-splices with anything else, you're probably not using the right tool. Stein does sell the jaws for their crimper frame that will do a proper job. So, if you don't want to go lookin for a used pair of the expensive ones Walt linked to, then buy the crimp frame and jaws from Stein for ring terminals and window style butt splices.
 
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For AMP Terminals I like the aircraft quality PEW crimpers made in Germany by Rennsteig. The AEA had Rennsteig tools in their classroom and I was impressed enough to order up a Rennsteig 619 060 3 0.25-6.0MM crimper for my every day use. Cost me $211 in 2016. It does the double crimp (wire contact and insulation strain relief). High quality product:

R_619_060_3.jpg



Rennsteig also makes some great wire strippers that release at the end of their stroke.
 
For AMP Terminals I like the aircraft quality PEW crimpers made in Germany by Rennsteig. The AEA had Rennsteig tools in their classroom and I was impressed enough to order up a Rennsteig 619 060 3 0.25-6.0MM crimper for my every day use. Cost me $211 in 2016. It does the double crimp (wire contact and insulation strain relief). High quality product:

R_619_060_3.jpg



Rennsteig also makes some great wire strippers that release at the end of their stroke.


Are they really any better than the same looking ~$35 version from Amazon? Replaceable jaws, adjustable “squeeze”. Stein air sells them too..
 
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