Hot Rods Soldering electrical connections 101

No matter what electrical component you might buy for your car the same thing is always mentioned on the item or the package that it came in( Alway solder) your connections No other method is secure over time through vibration,moisture etc; it is improper to do it any other way..I admit I have neglected to always solder my connections but recently thought what the heck on this project I will .

So I am using electrical solder 40%Tin & 60% lead ,always tin the tip ,use lead free flux .When I yank on the connection it will sometimes come apart ??. My connections are always clean or new, I do wait to see a puddle proper heat, What am I doing wrong ? Am I using the wrong flux ( lead free) any suggestions ?? Gene in Mn.

 

Use rosin core lead solder.

See this video from that video site. Link ----



Also, the BIGGER the glob, the better the job does not apply here.

 

I use rosin core solder, no extra flux required, as long as the wire and whatever you are soldering it to doesn't have any oxidation. If you heat the wire and connector (from the bottom because heat rises) until its hot enough to melt the solder and don't let anything move until the solder cools, you will have a strong joint. Tinning the tip and having enough extra solder on the tip to help heat conduction speeds up the process and should give you strong joints.

 

I would question the premise, that a soldered connection is the only way to go for high vibration. "No other method is secure"? Not trying to beat up on you here, but the aircraft industry, NASA, Tektronix don't seem to think so.

 

Sta-kon connectors work best.

 

I have been solder wiring for decades. I bought the lead free rosin core solder to use on our homebuilt aircraft wiring and really struggled with that. My welder friend was lecturing me on the right way to solder so I said you do it. He got the same abysmal result. I still had some rosin core lead solder special for wiring and immediately was in heaven. I bought 4 rolls of the electrical solder with rosin core electrical lead solder from NAPA just in case it becomes obsolete. Check in the welding section of your local NAPA and use the lead solder. It takes a second to put the solder gun on the underside and a couple taps with the solder its done perfect. I soldered in all the crimp connectors on the airplane project and then used the weatherseal shrink tube to cover the connection. The rosin core does not require flux and wicks into the joint with ease.

 

Just as a sidebar.
The energy we call heat, DOES NOT "RISE". It emanates in all directions from it's source.
Heated AIR rises.
Just to set the record straight.
Other than that, everything else you said was true.

Roger

 

Leaded solder is not available to consumers in the european union any more. Another step to keep lead out of the environment, which I suppose is good, but it makes life harder. Companies can still buy the leaded stuff here, but not average Joe.

 

The main thing is to heat the wire until solder will flow onto it. Put the solder on the wire, not the iron which should be well tinned before you start. Rosin flux for electrical work and The acid/zinc flux paste for other copper. like tubing, etc. Acid flux is a bit tolerant of minor crud on the wires and is easier to work with but must be thoroughly removed after soldering to prevent corrosion. When soldering wires twist them as shown in the you tube picture and insulate with shrink tubing. Cleanliness is a must.

 

Any time I see good lead-based solder at a garage sale/yard sale I buy it.
I learned how to solder in 1970 when I was a sophomore in High School, at the TV repair shop I worked in.

Clean wire, appropriate flux, heat the pieces you're soldering, not the solder. I always use heat shrink over my connections as protection and strain relief.

 

The most common solder used to be tin/lead, 60%/40% and was very forgiving as far as heat application and flow out. Lead has all but been eliminated in most solder except specialized applications, hell wheel weights aren't even lead anymore. The solder with a "core" means it has a hollow center filled with flux, the most common for electrical work is rosin. Acid core solder is for use with brass radiators and copper other than electronics. As you heat up the copper it oxidizes when in contact with the oxygen in the air. This oxide can create a barrier that makes it hard to get the solder to "wet" the surface or in other words it prevents the bond from forming between the solder and the copper. As you heat up rosin core solder the rosin melts at a much lower temperature and coats the surface to shield the copper from the oxygen and lets the solder to get to the surface of the copper without dealing with the oxide that can prevent solder joints from sticking. Overheating the copper wire can burn off the flux and create an even tougher oxide barrier, I have seen this many times when people use butane or propane torches to try to solder with. All these issues can create a poor solder joint, the new lead free solder which can be 95% tin has to be heated to a higher temperature to melt which causes problems as well. Every time I am at a garage sale and I see tin / lead solder I buy it!

 

When I first started working for Freightliner all connections were soldered. By the late 90's almost no connections were soldered. We are talking over the road trucking. Lots of miles and a lot of vibration. I don't think doing away with solder connections had any effect on electrical problems. A good connector with a solid connection between the wire and terminal works just fine.

 

When you strip the wire, run the bare wire through a piece of folded 400 sand paper or a scotch pad, until it is shiny. Makes all the difference in the world. Even if the wire looks clean do it.

 

If you are out garage sale or swap meet shopping be aware that the solder might be labeled sn/pb as these are the scientific abbreviation's for tin lead. This Kester brand they called "44" used to be the greatest stuff to use when I worked in the electronics industry many years ago.

 

No issue with a PROPERLY crimped electrical connection but over crimping will break wire strands and create problems down the road. Most of the crimped connections you are referring to are created with a brand of terminal that is engineered to be used with a corresponding engineered crimp tool and is calibrated and tested often. The Harbor Freight tool crimps may or may not be reliable.

 

There's a reason the race engineers DON'T solder, in wire to wire connections !
There's a reason most wire to wire connections in the Aerospace Industry...DON'T solder.

Vibration... Vibration kills solder joints.

If you feel that you NEED to use solder, use as little solder...as possible, in both length AND thickness, and then use shrink tube (NOT tape) over the joint, to help reduce the vibration.
Quality, crimp connectors with shrink tube to stabilize the wire are normally a better, longer lasting connection.

Mike

 

My Dad gave me a soldering iron on my 8th birthday. Correct soldering technique is very similar to sweating copper pipe for plumbing, heat is not applied to the solder the object to be fused is heated first then solder applied. Cold solder joints are generally due to insufficient heat, and too much heat can work harden or turn copper wire brittle. I've been building cars since the '60s and have always soldered connectors and never had a failure. When people state that NASA crimps the connectors the aerospace and military suppliers/contractors have specific wire, connectors and crimping tools that civilians can't purchase. A temperature adjustable soldering station is very helpful when learning to solder. As others have mentioned the components being joined by soldering need to be clean and not corroded. Just like welding, practice makes better connections if basic procedures are applied.
I worked for a Swiss manufacturing company for three years that supplied the finest recording equipment for the motion picture industry and all connections were soldered not crimped. Vibration does not cause a failure, but over heating the wire can result in a fracture.

 

Soldering works great if you do it right. Crimping works great if you do it right.

Note that the important thing is, you have to do it right.

 

I think I’m going to move to the no solder camp.

 

Well ,I have always soldered all my joints for over fifty years, with no failures. All the tricks and techniques have been mentioned. A good solder joint is always shiny. I always first make a mechanical connection, solder, and cover with heat shrink or a very good quality of electrical tape! The solder I always used and still have a good a lot of, was Radio Shack solder. It seemed to be the best to me! Proper heat, clean joints are the key!
Now, you are probably going to get scolded by Crazy Steve for soldering wires! Lots of guys have informed us it is not the proper way to connect wires. But for me old habits die hard!

But if you move to the no solder camp, make sure your crimp properly! A poor crimp is way worse than a poor solder joint! I ran into many problems with crimps in the Fire truck industry!





Bones

 

This subject has been kicked around the block several times. The bottom line is that properly crimped connections are the best way to go. You will never see soldered connections in any military situation, always crimped. A soldered connection will always fail over a crimped wire end. You can prove it to yourself. Crimp one connection and solder one. Place them both in a vice and wiggle them back and forth and the soldered connection will fail first every time. By the correct crimping tool and use the proper sized connectors for the wire you are using and do the job right. Do not use those "one size fit's all" crimping tool. Never use shrink tubing on the fitting. If the crimp somehow fails the shrink tubing can hold the wire in place causing amperage build up. It can also make troubleshooting hard to do. Use the proper insulated wire end if required.

 

I solder where I have to.

but most of the time I crimp with good quality crimps and crimping tools.

most manufacturers require crimp connections on wiring repairs .

to many things can go wrong with a solders joint .

 

I wonder how they made all those radios, that helped us win WWII?



Absolutes usually have exceptions.

 

Another subject with no winner. Be a Frank!

Ben

 

As long as the wire/conductor is copper, brass, or mild steel, the resin cored solder should tin the joint and form a "fillet". If there is a noticeable junction between the 2 (like a non-penetrating weld), you have dirty or corroded conductors, or are trying to solder aluminium coated wire or something that solder wont take to, or not enough heat.
If the surface looks crystalline (not shiny), you have a dry joint, usually from the joint moving while it is cooling down.
And don't tell the thousands of solder joints I have done in F27 aircraft that they're not supposed to be there.

 

Says the guy with the FREE BEER- just click here. That sure doesn`t work.

 

What, did we fall into a time warp and it's 1940 again???

Detroit has used crimps in their harnesses since at least the late '40s if not earlier, you'll be hard-pressed to find a factory solder joint anywhere in a harness. Field-installed solder joints have been illegal in residential/commercial/industrial electrical systems in the US for at least 70 years. Aerospace and mil-spec do allow some soldering, but only under specific limited conditions and those are disappearing over time. Electronics is the only place where soldering is still widely used, and even there it's limited to 'factory approved assemblies' if UL approval is needed.

Solders main failure is the lack of a mechanical connection. In a lot of the places where soldering is still allowed, you have to establish a solid mechanical connection before soldering. Solder can start softening at temps as low as 300 degrees, without that mechanical connection the wire can fall out of the connector. Don't believe me, try using it as repair filler when powdercoating.... it runs right off...

Here's how to do a proper crimp... Technical - Crimping Tutorial | The H.A.M.B. (jalopyjournal.com)

 

Proper connectors and proper tools-never had a problem. We used crimp connectors for years on overhead lines carrying extreme amps under high tension.--still the standard.
I still use tools I used in the line trade as a lineman etc for 45 years. Stacon, Nicopress and Burndy tools.
On battery cables always use an overhead line press-have seen a few that failed when done with indent type tool..
I have seen quite a few wiring failures due to inferior connectors and tools. Have wired many cars. Quality bare connectors and quality shrink tubing as well.

 

I just tried it and got my free beer - must just be your computer.

 

uh....this is the HAMB, remember....