What do the experts say about wiring: crimp, solder, then heat shrink, or ?!?!?

I was at radioshack today about to buy a soldering gun (with light! ) and terminals to practice with, when I realized I wasn't 100% sure if that's how I should go.


MAD electrical says to use non insulated terminals, use a 9.5" klein crimper on it, *then* solder the connection not beyond the barrel(if I read it correctly), and use heat shrink. My automotive electrical handbook says just crimp and heatshrink tubing, no solder. Others say just solder and heatshrink.

What say you?!? What do the major kit makers like Painless or Ron Francis suggest?!?

Thanks in advance!

 

The MAD instructions sound like the best way to go. I'm a lazy ******* and just crimp them. But I also live in AZ where we don't have corrosion problems....

 

uninsulated crimped together, heat w a fine pocket torch, lighter, or solder gun, then solder w fine flux core solder. then shrinkwrap. dont forget to slip the shrinkwrap on before soldering, lol.

 

Like Skunx said. It's the best way.. If you got yourself a pistol grip gun, get into the habit of tightening the two screws that hold the tip, every time you use it..

 

Solder is the best connection... a connector will fail if only crimped way before a soldered joint will!

 

I was in the car audio biz for years solder is great if done right as are crimps,I prefer crimps on a end with shrink tube make sure you crimp in the right place and then shrink tube over that....However INLINE I hate **** conectors and will always solder with shrink tube over it (in a splice),just make sure you have no barbs in the solder FYI both are just as strong if done properly,

 

i know on new cars gm says to use heat shrink **** connectors crimp then heat w torch till glue comes out the ends

 

Back in my dirt track racin days I lost a pretty good paying race one night when a hunk of mud flew though the engine compartment and ripped the wire off the feed side of the coil. After this I quit crimping and started soldering and heat shrinking all the terminals on the car >>>>.

 

I only use non insulated terminals and the correct Thomas & Betts crimp tool. Then I shrink sleeve all connections. It is important to make the the crimp correctly.
High quality terminals are a must. Especially **** splice terminals, use seamless terminals for these, and as few as possible. Buy your supplies from an industrial supplier like Terminal Supply Co. You can find them online, they are happy to send you a printed catalog if you prefer. Also route your wires with attention to heat, abrasion, and weather issues. I wire race cars, hot rods and customs. Like Squirrel, I live in a dry climate, and do not solder. It takes long enough to design and wire a complete car well. Use quality parts.

Craig

 

They claim you shouldn't solder auto wiring because the vibration it gets driving the car will eventually cause the wire to fail there.

I soldered wires in a hell of a lot of car stereo jobs as a kid and I don't think anyone ever broke one. I guess if you used the wires as a junmp rope and hop down the road.... but that's probably why they say not to solder beyond the barrel of your crimp.

 

i can understand this, in a high vibration situation, as the heat would have slightly weakened the area by the joint. but like you said, it would really take some abusive treatment to really break it

 

Years ago I was Mil Spec qualified and we soldered connectors that were designed for very high vibration environments such as HARM and Sidewinder missiles The concern with soldering a connector was with how much the solder wicked up under the insulation and caused a stress point. That was 20 years ago, and I don't remember the spec, but I still have my mil-spec wire strippers, and probably the biggest thing to watch for when making any connection is to not nick the wire when stripping it. Using a pair of sidecutters or a knife to strip the wire will cause a failure faster than any soldering on a wire.

 

Mark at Mad Electrical is good, really good. His advice comes from years of experience and pride in his work.

 

I like Leon am Certified to mil-spec standards (J). Solder is not used in unsupported high vibration apps. Lead solder is brittle. We use a crimp and solder and heat shrink on the mobile communication platforms we put together (strain relieved). Or just crimp (non-relieved).
Meatball... Solder joints will weaken and break before a properly crimped terminal.
But they do make what is called a solder sleeve for **** splices. Try them out they work great.
I will not get into equipment as we use some high dollar stuff but as was said make sure you do not go low ball on your crimping tool. DMC makes a great tool abit spendy but you will never have to buy another crimp tool and all your crimps will be correct.
Fitysix

 

I work for a military cable manufacturer, and Fiftysix is exactly correct.

 

I work for a defense contractor and by default, I'm the local expert on military wiring standards and practices.

Every crimp type lug gets crimped, period. There is no soldering required. I have seen them sleeved with shrink tubing, which is not a bad idea if there is some vibration to consider.

You can coat them with conformal coating (aka Conap 164) to ward off corrosion after they're hooked up. The best bet is to just crimp them and make sure that you have enough strain relief and or a "service loop" in the wire. Which makes sure that the wire is not being tugged on. The service loop is supposed to give you at least one more shot at making a field repair if the wire does break.

Anything you want to know about crimp lugs can be found in MIL-T-7928.

Bob

 

I love Daniels crimp tools. Give me their HX4 handle and the Y501 die set and I'm set to crimp almost anything.

Bob

 

Bobss396,
I am glad you are the resident expert in Mil-spec wiring. One more hat I don't have to wear.
There are some standards wich call for solder re-inforcement on a crimp. Some projects ( I also work for a contractor) call out for it. I for one (on my own schtuff) always make sure of strain relief and crimp (except for **** splices- enviromental solder sleeves).
There is a fine line between service loops and strain relief. Service loops are exactly what you mentioned but if not done correctly can put strain at the point of termination. In some apps there is no room for service loops at termination so supporting the wire for strain relief is required. In those cases a service loop can hopfully be lost somewhere else in the routing.
Fitysix

 

gotta agree with most these guys I had a car audio store for years and the ONLY time we used solder was for inline splices,otherwise everything was High quality crimp conectors...I have two crimp tools I love one is a Klien the othe is a snap-on with the head @ a 45 degree angle great for strange angles cause you can see what the hell your doing...fitysix thanks for the info I will try it....can always learn new ideas

 

My company builds Mil-spec training devices that are designed to survive in pretty harsh environments, lots worse than your car. Most of the internal wiring harnesses that require a connector are crimped and heat shrunk.

 

Expert or not I just finished building battery cables for an 84 volt 1915 Milburn Light Electric Coupe. I used stranded welding cable on 14 deep cycle 6 volt heavy duty batteries. We crimped heavy duty lugs on first and then soldered them with an induction heater. The solder will seal the joint from corrosion. We then used the type of shrink tube that has sealer in it that melts with the heat that shrinks the tube to cover the joints. The other type is a vinyl tube without sealer. This should last a long time. John Worden

 

Yep, this is how I have always done it -- I am very picky when it comes to wiring. Not only will this be better electrically & mechanically, it is a hell of a lot more handsome than those ugly crimp on insulated connectors. Remember, solder is best electrically, and crimping is best mechanically (vibration!).

 

There are solder type lugs out there, but the PIDG type Amp and T&B lugs with the plastic wire insulation are designed for crimp only.

Yes, strain relief is one thing. As long as the wires have some slack in them, you're covered. Mil spec 454 (rqmt 9?) has some pictures in it that show what not and what to do. Other IPC specs have them as well.

Service loops can often be dressed back into the main wire bundle. I tell my harness people that you can always "lose" an inch of wire if they are a bit on the long side.

Bob

 

I crimp to hold the terminal while I solder it and then the shrink tube. I'm more concerned about looks than meeting Space Shuttle standards (not that there is anything wrong with that) I have a bunch of the plastic coated terminals but I cut the ugly plastic off of the terminals. The wires look much more professional without the bulky plastic insulation under the shrink tube.

Any wire that is exposed to the elements should have the ends soldered. IMHO Water will wick into the wire strands just like the solder does. It can't if the space is already occupied by solder. I don't entirely trust the shrink tube to seal out all of the water.

I bet that 75% of our wiring repairs for state inspection were due to crimped wire connectors or twisted and tapped connections.

 

Go to an industrial electric supply store - Graybar is one if they're still in existence.

Get a box of Burndy (brand name) HY-Lugs in the gages and bolt/stud sizes required.

These are used in the power industry to connect relay and control wiring.
Crimped, not soldered although they are tinned to start with.

Use some shrink wrap after the crimp.
Longer than normal if it's in a high vibration area.

Never had a problem with these with any car and over 14 years on the 32 with no probs.

Far better than the parts house thin gage sheet metal terminals.

No pics, but I can post some this afternoon if you like.

Get a good crimp tool, mine's ex-Navy.

 

The main thing is where the wire is supported. If the wire is allowed to flex inordinately, it will fail. A nick, as stated, will cause a stress-riser and hasten the failure. When I solder, I always solder above the crimp, and try not to allow the solder below the crimp. This after I had a joint fail below the crimp due to solder not allowing the proper flex. And I had not properly supported the wire.

I just rewired a table saw that had been wired in the early 50's with a mix of stranded and solid. All the connections were twisted and taped, that's all. And this worked for over 50 years. But it's not right and any undue strain would have caused a short or open, creating a failure. Why do I mention this?? Because you will always have people telling you that you need not do "all that rigamarole, it'll work fine". And it might, for awhile, but it's not "right".

Have pride, do it right.
Cosmo

 

John,
I love three stage crimps on 0000 cable. Adhesive heat shrink is the ***s in certain applications. Messy to cut off! Would love to see pics of what your up to.
Bob....there are alot of ways to do things depending on application. Got all the books and training and the books can be invaluable when you need refreshers or just beginning to do Mil type wiring. We use a mix of insulated and non-insulated lugs and when we do use insulated I do not solder them.....makes a mess.
Of course in my line of work there is abit of over kill with all things. When
these toys go into the sand box stuff needs to work now.
Automotive applications call for mechanical termination..insulated or non.
Again...the crimp itself is what is important. A bad crimp will not stand up to a pull test and will eventually fail.
Fitysix

 

nice thread, maybe someone could do up a few pic of good conectors and a proper crimp job, thanks

 

I have deep respect for You mil-Spec guys. If I ever have to shoot my car out of a cannon, I'm calling Y'all first.

My Background comes from Drag Racing. here is how I was taught, and subsequently, how I wire...

I will not buy a plastic sheathed connector, unless it's a decent one I can get the plastic off of.

The use of **** connectors for me has become pretty rare. i keep a large number of early style automotive grade terminal ends, and the housings they snap into.

everything getts crimped with the correct type of crimper- I have 3 styles- one is made by "tool aid" (funny, name , I know) it does the double size crimps which grab the wire and the sheath. That would be gteat, excet I always end up stripping an extra 1/4 inch and cripming both parts to wire. then I use a micro torch ( power probe type.) to heat the terminal and solder it with rosin core solder. (flux ****s. it gets everywhere...)after that, I hit it with the appropriate sized adhesive filled heat shrink tubing. They it gets snapped into the connector, and viola! it's no longer a "wire" it's a "wiring harness"

adhesive filled shrink tubing.
on a side note, most folks don't know what the hell we are talking about there. it is basically good 'ol heat shrink tubing with a thin layer of Hot Glue inside. when You pinch it closed in Your fingers, You will hear it "pop" apart. when it is heated, the glue melts and seals off the tube. pros- this stuff is an awesome barrier against mosture. cons- if You manage to grab it while the hot glue is still in liquid state, well, ouch.

the way the wire is run is as important as the connector. if it is tight, the connectors have tension on them, and as a result, will fail. What You want (again, in my opinion) is enough slack in the run that You have a tight bundle of wire, but the entire harness has some motion in it. I also usually place a "drip run" in the harness, too. meaning that immediately before the workpeice ( switch, relay,Your ******s...whatever You are running power to.) I have a dip in the wire that runs an inch or 2 below the peice. That way, in the unlikely ( okay..quite likely if You own any of my cars) event that water ends up on the harness, it wont end up in Your conector or workpeice, as it will (in theory, anyway) drip off, first.

the biggest mistake I have seen made is mounting relays upside down.
They turned into tiny little buckets of water! Yay "nothing works!"

 

Another tip for reducing strain at connections is to make sure that your main bundle is restrained. A loop clamp on the firewall (or wherever) usually does it. That takes most of the strain off the lug or other termination.

If you are really serious about moistureproofing connections, you have to coat the terminals with conformal coat or Conap that I described up the thread. It brushes on very easily (you need a black light to see it though) and totally seals the connections environmentally.

We use it on aircraft connections that are exposed to elevations of 60k feet and are also exposed on the deck of aircraft carriers.

Bob