I get asked a similarly simple question often and it rivals, "what came first, the chicken
or the egg?".
The debates on this question can get pretty interesting and that question is simply, should
I crimp, or should I solder?
My quick answer is almost always going to be to crimp.
There are pros and cons associated with each and I'm going to cover some of the highlights
that are associated with them.
Any connection should start with quality components and the correct tools for the job starting
with your wire strippers.
Stripping wire with your pocket knife, a pair of side cutters, or the wrong gauge slot in
your stripping tool can cause breaks in the conductor that can result in excessive resistance
as well as frayed conductors that can cause failure over time.
Let's start with crimp connections.
Crimped electrical connections have been around since they were introduced in the early 40's,
over the years technology as well as materials have improved since the early days.
Most people think that a crimp connection just crushes the contact in the wire as you
can see in this cross section of a poorly executed crimp connection.
In reality when done properly as you can see in this cross section crimp, the pressure
involved causes the metals to flow, resulting in a wielding of the metal surfaces, that'll
produce a gas tight as well as a connection with minimal resistance that will not allow
oxenisation over time.
It's a good idea to pull test your connections once you have made them.
You shouldn't be able to pull the wire out when applying a reasonable amount of force
to that connector.
In most cases the stress to it's failure point, the wire should actually break before coming
out of the connector.
Over crimp connections are just as bad as under crimp connections as it will make it
brittle and prone to failure.
In short proper crimp connections create a weld between the connector and the wire creating
an environmentally resistant long lasting connection without creating a brittle, failure
prone joint.
The key to proper crimp connections are simple, use high quality materials that are designed
to work together utilizing quality connectors, the proper gauge wire and the proper crimping
tools and techniques.
In front of us you see a broad assortment of crimping tools.
What you're going to find you do not want to use, that are not acceptable, is going
to be a hammer, channel locks, lineman pliers, things like side cutters.
You want to make sure that you use the proper crimping tools every time.
There's several crimping tools available on the market that can range from the basic,
essentially a hard ware store type of crimping tool, which I really don't recommend, to professional,
quality crimpers.
They can range any where from a standard, compound leverage manual crimper, all the
way up to some high end hydraulic crimpers.
The key is again to use the proper crimping tools.
If your crimping ECU pins for Holley EFI, it's going to be important to make sure that
you use the correct crimpers, Holley part number 567-100 is a crimper that's available
for that.
We also have a crimping tool that has interchangeable anvils, it's available through MSD, to cover
a lot of your other crimping needs, and the key is making sure that your using the proper
connectors.
When it comes to applications with sub harnesses that require you to disconnect and re-connect
your connections, I like to use commonly available weather pack as well as metro pack connectors
for those applications.
Again one of the keys to that is making sure that when you make those connections, and
your crimping the terminals, that you use the proper crimping tools that are designed
for the job.
When it comes to eyelets, spades, and buck connectors, I personally like the non-insulated
type.
When your buying these connectors you want to go for a good quality connector, preferably
that is either a seamless or a braised seem type of connector.
Once you get done crimping these connectors, it's important to make sure that you put a
little bit of shrink wrap over it and I prefer the adhesive lined shrink tube.
One of the keys to properly crimping these type of connectors is to look at the connector
in the orientation, look for the seam and you always what to do what they call, saddle
the seam, in which case you make sure that your, D10 on the crimping tools is properly
aligned opposite the seam.
Once properly crimped with your connections, one of the things you are going to find is
that it should give you a good, solid, secure joint that can take actually quite a bit of
abuse in order to separate.
Oh, so people that thing that crimped joints are not a secure solid joint, probably haven't
been doing it properly.
One of the keys to that again is making sure that you you use the right crimping tools.
Generally I would use this pair of Thomas and Bett's crimping tools or this ratcheting
style crimper, either way just make sure that you are using the proper crimping tool and
your crimping it in a proper place, provide the required bell mouth for the correct strain
relief.
A few companies offer a nice selection of quality crimp connections, that have the adhesive
lined shrink tube built into those already.
These connectors are pretty nice and I always keep a few of those in my wheel house, but
I usually prefer to shrink non-insulated connections because it allows you to visually inspect
your connector a little bit easier.
Holley offers connector kits for popular engine applications in an ever expanding line of
high quality wiring components and solutions to fit your needs.
Next we're going to talk about soldering.
So we talked about crimp connections so now let's talk about soldering, soldering seems
simple enough doesn't it?
You strip, you twist, you heat, you melt, you repeat.
Well it's really not that as simple as it may sound.
For my experience over the years, finding properly executed non-factory solder connections
in automotive wiring was a lot like buying a lottery ticket, sometimes you get lucky
but unfortunately most of the time you don't.
It's starts with clean, oil free, non-corroded materials and a soldering iron that's set
to the proper temperature with the proper tip for the materials and connector being
soldered.
I prefer solder with about a 30,000ths diameter with a 60/40 rising core, 60% being tin and
the 40% referring to the lead content.
I prefer it due to it's low melting point.
What you don't want to do is use one of these while your soldering your wires.
Now there's a time and a place for this, if your soldering a large gauge battery cable
and for example you would generally, a lot of times end up utilizing a torch if your
going to do that.
You want to make sure that you do have that right solder, you never want to use a acid
core solder with electrical wiring and you don't want to use a very large diameter, large
gauge solder VS the 30,000ths because you'll have to apply way too much heat, which is
going to cause you to have some issues with a poor connection.
So we're going to show you how to properly solder a joint, when I solder connections
in the case of this buck connector, I like to interlace my conductors with each other,
kind of fan them out a little if you need to.
Interlace them through and twist the conductors opposite of each other, which itself will
give you a semi secure joint, and it also doesn't effect the overall diameter as much
as some other twisting techniques.
Over the years I've found that these little helping hands can actually be quite the helping
hand when it comes to soldering your connections because it allows you to free up your additional
hands.
You want to make sure that your soldering iron set at the proper temperature, with a
clean tip, and again using the proper solder.
You want to apply heat through the back side of the conductor, you don't want to apply
the heat directly to the solder.
It's ok to put a little bit of solder on the tip to help it conduct heat a little faster
to your wire, but you actually want to heat the wire, and get it hot enough where it melts
and it gives you good penetration.
By putting the heat on the back side of the conductor and the solder opposite, it will
actually pull the solder towards the heat, which will allow it to flow completely through
the joint giving you a nice solid connection.
You want to avoid applying too much heat and too much solder as it can cause some other
issues that is associated with the joint.
As I had mentioned, you never want to touch the solder to the iron in order to start the
flow into the joint.
Doing so will result in a cold solder joint that is porous, can be brittle and prone to
resistance.
A properly soldered joint should be smooth and shiny, it should never be dull, if it's
dull or it looks like solder is just globed on, it's probably a cold joint.
On a short side note, if you use lead free solder it's generally going to look duller
than a lead based solder is going to look.
The most common mistake that we see in the field is wicking, and that's actually when
there is too much heat, and too much solder that's physically applied to the joint and
it causes it to wick underneath the insulation.
We look at our nice flexible multi-strand wire here, we can see that it's quite flexible,
and it can take quite a bit of movement.
We go to this particular joint, I intentionally wicked this joint, and if we apply some pressure
to the outside edges of the conductor, we can actually see where it's become ridged
out underneath the insulation.
What happens with too much heat and too much solder is actually wicks the solder out into
the insulation, and what happens is it takes our joint, and unfortunately, it makes it
quite brittle and prone to failure.
It's one of the reasons that crimp connectors, a lot of the times, are better and why I generally
go with them is as you saw on the earlier video on crimps, the connection that I crimped
took a lot more abuse.
I strongly advise against soldering connections on small gauge wire, generally if your in
the 20 gauge or smaller, 22, 24, 26 gauge wire and it's always better to crimp that
connection.
If your soldering bud splices it's a good idea to create a strain relief using 2 over
lapping layers of adhesive line shrink tube.
When creating a strain relief with shrink tube you want to use 2 different lengths,
that way it over laps and gives you an additional amount of relief.
Go ahead and we're going to shrink the first layer on, make sure that it's centered up
and I like to use adhesive lined shrink to give me a good tight seal.
We'll go ahead and we'll put our secondary layer on and make sure that you over lap the
ends of the first layer.
Applying the overlapping edges gives you a nice strain relief, especially once this cools
down a little bit.
It will allow it to be resistant to damage to that solder joint due to flexing.
Most of the time I crimp, but depending on the application I will solder or crimp and
solder the connection.
The cost of crimping tools can be high, and if your going to preform quality crimps then
they really are a required investment and well worth the cost.
Maybe you are lucky and you have a buddy that owns them and he's kind enough to let you
use those and borrow them from time to time.
If you don't have access to the proper crimping tools for your connection, but that connection
can be soldered, by all means PROPERLY solder and shrink those connections.
What ever method you choose just remember a couple of simple things and that's to do
it properly.
Leave your wire nuts in your house, your T taps in the trash can and your twist and tape
methods to your competition.
For more recommendations and tips on wiring your vehicle, check out our other great Holley
tech videos.