Crimping electrical connectors... Sheesh... (1 Viewer)

[e9999]

As you all know, I'm all for improvised tools and DIY, even when not the most efficient way to go, often because I enjoy the challenge.
But when it comes to crimping electrical connectors, geez, I see so many bad crimps, both in real life and on Youtube. Makes me shake my head in disbelief.
This is one of those things where I'll actually buy the proper tools, painful as it may be...
The difference between a proper crimp with a good tool and the improvised ones is often night and day, just by looking at them, let alone electrically.
Don't cheap out on this one, folks.


(prompted by yet another Youtube video with some guy struggling to crimp an MC4 with cutting pliers...)


-Rant (?) over-


















going right now to look at some good crimps to make my life wholesome again...

 

[peesalot]

And if you are gonna go with a pliers crimp , solder the thing so you don't have to wiggle it to get it to work sometimes.

 

[aztoyman]

How bout a tutorial? Tool recommendation? Not being a smart a$$, I really want to see and learn.

I had access to Deutz kits and such when I worked at a Cat dealership. I'd like to get my hands on some better tools for my toolbox.

 

[e9999]

well, my point was really to suggest that this is an area of DIY where the correct tool for the job is best.
The tool would depend on the type of crimping / connector you want. There are many different types. So I can't very well recommend just one.
So, once you identify what connector you want to crimp, e.g. PP, MC4, ring end, ferrule, etc, you look at that specific type of crimper and then go through the usual routine of Amazon ratings etc, taking into account whether you want good quality or generic, cost etc, as I'm sure we all have done many times. On the better side, you can't go too much wrong with Knipex or Klein. But those -and especially Knipex- are significantly more expensive than the generic chinese ones, of course.
I have several of both types. And to be honest, you can tell the quality of the tool easily enough by looking at it, but the results probably don't vary too much. I have some cheap chinese crimpers that work just fine.
IMO, a cheap chinese crimper will almost surely do a much better job than trying to improvise something with the wrong tool.
There are also crimpers for which you can change the head for different jobs. And hydraulic ones for bigger or more critical stuff.
Of course, there are lots of vids on YT about this that will show you how to use them and review specific ones.

 

[peesalot]

A pair of Kleins is a great start. and a dot of solder is a great finish.

 

[sdnative]

Check the local craigslist / offer up as well. I picked up a very lightly used Thomas & Betts TBM8S with a full set of dies for around $90. It will crimp down to 8awg lugs. Anything smaller I use a ratcheting crimper (I think I got mine from Harbor Freight but can't go wrong with Klein).

 

[e9999]

If I were to try to oversimplify crimping for typical electrical connections, I would say that there are two main categories of better crimps:
- the more straightforward outside hex etc kind of crimping, typically used with ring end connectors, ferrules, and the like.
- the more sophisticated "fold the wings in" kind for PPs, MC4s etc.
Apples and oranges.
The former can perhaps be improvised with DIY to some degree of success, maybe with the help of soldering (which I don't think is necessary or useful if it's a good crimp in the first place). The latter less easily so (what I was commenting on about that YT vid).
For hex crimps, I mostly use a generic chinese hydraulic crimper with many dies. Inexpensive. Works great so far. Good control of pressure and size.
For the wings folding type, I use various dedicated manual crimpers. Not too expensive each, but adds up.
I have long ago abandoned the use of those little spade and ring ends affairs that you squish flat. Often used for DIY car work. Dreadful little things.

 

[george_tlc]

A well executed crimp does NOT require solder. If you are going to solder, then the quality of the crimp (unless totally awful) will make little to no difference.

The issue with solder is that it will typically wick itself up into the strands inside the insulation. You now have a brittle versus flexible section of wire that will behave poorly in an environment with vibration or some flexing. The automotive industry doesn't solder connectors, they are crimped - of course they are professionally crimped with the correct gauge for the connector and with the correct crimping tool (usually automated).

If I use solder on a connection, I'll use adhesive lined heatshrink to provide some extra support to prevent flexing near the soldered crimp area. The solder must also be a no-clean type with a passive flux or you'll have ongoing corrosion issues to deal with. It obviously has to be a well execute solder joint and often the DIY folk will have poor soldering equipment, technique and solder.

A well executed crimp is gas tight and will prevent corrosion occurring between strands and strands and the crimp. The issue is getting a well executed crimp The wrre gauge must also be within the range for the end being crimped.

At the very least perform a decent tug test on any crimp (soldered or not) - what can look good is often not good...

cheers,
george.

 

[Grayscale]

AIRIC solid connectors, common crimping tool, and shrinkwrap. Super clean and not bulky when done. Very reliable, and very close to water resistant. Easy to crimp without nylon insulation to get in the way.

Traditional ring terminals can have their nylon insulation removed, and you get better crimping as well. The generic nylon insulated stuff that connects and disconnects (unless OEM factory) is junk, don't even bother with them, just use a fresh permanent connector.

I also use shrinkwrap to insulate sections of 'bailing wire.' It is really a good material from a metallurgical standpoint, and deserves a place in the on-board toolbag. Bailing wire loops is used where zipties would be employed normally, and they can be opened and closed without having to replace them. Better yet are cable clamps, but, who wants to drill and deal with non-captive nuts to fumble with on the backside?

Often I'm using solid connectors with two wires on one side (to fill the space for a good crimp while stepping-up wire gauges, or to make branches). Trim the extra wire off just behind the crimp. There is nothing worse than trying to crimp an under-sized wire in a situation that requires a gauge-up connection, but you can twist some extra material in there to make it stronger.

 

[Grayscale]

Top to bottom:
The standard fare. Can totally touch up the pliers/crimp-tool on the grinder for personal preference. The bailing wire zip-tie alternative with a few sections of shrink wrap for electrical harness.

The ring-end terminal in 1/4" or better can only be found in blue 14-16g., so I wrap the dark 18g. wire (to be trimmed off later) over with a white 18g. wire, then crimp. It keeps it from coming apart later, compared to doing it with just one wire. Why I can't find 18g. ring terminals for use with M6 and M8 body and frame screws, I don't know? I removed the nylon insulation (auto store stuff) and replace with heat shrink, so I can see what I'm doing and what I just did. The filler wire is how you do branching and gauge jumps with good tensile strength, every time.

The second wire down is an 18g. ring-terminal, complete, with a fresh solid-butt-connect, uncovered, and one with insulation. Nice, compact, strong, covered well. Months ago, I did a eye-glass frame repair on my mom's specs at the hinge with shrink wrap, even with all that pulling on the hinge corner (they don't fold on the repair side anymore), they still are fine months later (she doesn't want to go to the eye-doctor if she can avoid it. Other than it being black on one side, you can't even tell it is a repair.

The third wire down is a 16g auto store butt connector. It is a loop of textured metal, and when you press down on them, they open up a bit. This is the second major reason for buying the AIRIC solid connectors.

The fourth wire is a branch of a couple of 18g. on a 1/4" spade connector. Totally useful if you are working with a factory spade/connector stuff. It will be strong and clean looking when the Bic-brand lighter (works better if pocket-temp) gets some heat on the shrink tube.

I always wonder if I should dab the wire with dielectric grease after I strip the wire, before I twist and crimp. Sure, I need friction for tensile strength, but, I'm doing much better in that department since I started using quality butt-connectors and removed nylon coatings (yes, they sell them bare, but you have to Hillman them or mail order them). I might want greater corrosion resistance if the application location is in question? Btw, I polish 50-yr-old factory wires with steel wool, so that they are bright again, after stripping the insulation if I'm making a new crimp connection.

 

[e9999]

^ I would not think that putting dielectric grease (usually an electrical insulator, as the name suggests) between 2 surfaces (wire and connector) that you want to be in the best electrical contact possible is a great idea. Putting it on the finished crimped connector, especially under a shrink sleeve, may be helpful, though. Although I'd still prefer a shrink tube with melting adhesive.

IMHO, crimping these nice butt connectors with a little dent crimper could be improved on. I'd use a full hex crimper, personally. The idea of a good crimp is to remove all the empty space in and around the wire and make it a single solid block of copper together with the connector wall itself. That's why I like hex crimps because they *decrease* the overall diameter of the connector through cold flowing, not just *reshape* it, which may not be the case with a dent crimper if the wire does not fully fill the connector to start with.

But, eh, if it works well enough...

 

[Grayscale]

@e9999 A link for a good hex-crimper?

I was suggesting dielectric grease to deal with harsh environments - inside distributor cap (ozone), next to battery positive. Less is more, and I'm definitely not recommending doing it, just suggesting it as an alternative to my low-skills with soldering. With or without dielectric to protect copper seems to work in the short term, I just think that it might offer a bit more durability after it gets stripped. As its name suggests, dielectric prevents the flow of current - which is necessary for metal to oxidize - charge flows between cathode and anode metals and oxygen bonds to the copper. I'd expect it to impart some electrical resistance, but I'd rather have the brake lights actually on, even if it takes more juice? Ultimately, I really don't know.

?
https://www.amazon.com/Haisstronica-Crimping-Non-Insulated-Terminal-Ratchet/dp/B08L331FB2/ref=sr_1_1?crid=3CEPJZ9BANLQL&keywords=hex+crimper+uninsulated&qid=1668046912&sprefix=hex+crimper+uninsulated,aps,113&sr=8-1

 

[e9999]

that haisstronica crimper above is a dent type crimper. Probably better than the Oval crimpers like in your pic above but maybe still not the best way to go IMO.
For hexes, I see two common types of hydraulic chinese hex crimpers that may suitable for electrical connectors, they look like this:

the yellow one goes to smaller sizes, the teal one to bigger ones. I use one like the former. It's OK so far. I don't think that is a high quality tool, but it works. It can do smaller connectors - I think the usual range is from 4 to 70mm2 from memory, that's 12AWG to 2/0 I think. Check the specs to see if that'll do it for you. They can be had for less than the above (that's just a random pic, not recommending these specific ones). There are of course also fully mechanical hex crimpers, but I do like the control I get out of the hydraulic ones, I can fine tune the crimp size. One drawback is that the tool pressure is so powerful that the copper connector barrel material may flow through the gap between the dies, giving you "wings" on two sides. But easy to remove. Or I rotate the connector a couple of times in the dies to even it out and/or reduce/crush those wings.
I also have a "Tricrimp" mechanical crimper with changeable dies for smaller stuff. One of the dies has some hex openings (for coax crimping) but only 3 sizes or so I think, so that's a bit limited for hexes, but it does cover several other types of crimps. I use mine a lot for Powerpoles. And I think those dies will do reasonably well with MC4s as well. It also has dent type dies like the Haisstronica above and some squishing ones for insulated end connectors. I'm happy so far with it.

 

[Grayscale]

I never desired a different crimp shape/profile, but, I wanted the width of my crimpers to be wider/longer along the length of the connector and wire (for pressure over a greater area / length of wire . The jaws should be thick/wide enough that they get used for pliers by the lazy. It would be nice if the die lines up the soild-butt-connector in a groove on a die, for a machine-like result every time.

I keep a little pair of children's scissors (with the inserts for small fingers removed) in my electrical work tool and component box. The tips are rounded, and I they fit in my jean pockets. After I twist a stripped wire, I create the perfect length of the protruding end with sharp shears. It is so much nicer when the stripped insulation is butt-to-butt with the metal connector, after you have the shrink tube on. I wish that there was a better shear on the inside jaw surface of my common crimp tool.

Basically, my desire for better tools has been displaced by skills. I wish I could wire like the factory, but, I'm not expecting it to look like that when I'm done. My wiring looms work, which isn't saying much because those stereo installations in high school also worked. Still, we are pushing a pile of wire loom into an environment with a bunch of sharp screws and rough ends of sheetmetal - rough but, it works. The factory left my two vehicles with plenty of cabin leaks, so I'm always replacing a wet speaker. I think that I'm going to just pull the headunit and use it in my shed with an AGM 35amp/hr battery - I can't drive in traffic with touchscreen music, and aftermarket head units are too bright at night. Sometimes you eat at a restraunt and there is lipstick on the coffee mug or beverage glass.

 

[e9999]

^ If you use a mechanical manual crimper with no hydraulics, so, capable only of a given force limited by your hand(s) strength, I think you are better off having narrow jaws so the pressure is higher and the crimp will be tighter at that spot. You can then just do several crimps along the length of the barrel to generate a strong crimp (almost) everywhere. With wide jaws, the pressure will be lower and the crimp less tight.

 

[Grayscale]

Also for the bicycle cable end. Sure, I'll solder, but only if I have to.

 

[Mudder]

What’s the consensus on this style of crimper? It’s what I’ve been using from Home Depot but I’m willing to upgrade if it isn’t good. I’ve been using it for ring terminal connections only.

 

[Grayscale]

It looks like the Klein, above, was intended for insulated connectors? I'd love to try that tool. There is possibly a difference for coloring, and intended final profile/shape. I don't feel that my red-size jaws are inadequate for non-insulated connections no smaller than 18g, but still... Was the Klein intended for insulated (colored nylon), or bare connectors?

I can see why spade, fork, hook, (maybe) bullet, and ring terminals are just folded sheet. This is kinda the fault, when you squeeze/crimp, and they somewhat open-up (there is probably an ideal spot to crush but it isn't like the seam is marked on the outside of the colored nylon connectors, and the insulator never lets you see the result. The solid, butt-to-butt connectors solve this because they are both, substantial in thickness, and that there is no seam. The ones that are folded sheet are so much easier without insulation to make a good wire connection.

 

[george_tlc]

The jaws in the Klein above ARE for insulated connectors. There's also a jaw that allows crimping of insulated flag terminals (i.e. they are right angle wire exit).

In general I don't like any of those sorts of connectors in vehicles other than to specific spade pins (some aftermarket fuse holders/panels - e.g. Bluesea). For wire to wire I would much rather use a weatherpak or deutsch since they have weather proof seals etc - though of course larger in size.

If I have to use a spade style (the female end) connector, I'm very careful to pull test and inspect the crimp. In 'wet' areas, I'll use a liquid tape type product to seal both ends of the crimp area (where the wire enters and also the spade side area). I've gone back to inspect years later and the sealing scheme works well and is durable.

cheers,
george.

 

[Mudder]

My apologies, they are for insulated connectors. Mainly what I use but I do get the weather proof ones and use heat shrink over them as well.