Follow up to heavy gauge battery/jumper cables - which solder is best

[TomGolden]

Hi all,



As a follow on thread to my thread on making my own heavy gauge battery, jumper and winch cables out of welding cable, I think I will try to solder the ends on myself.



I used to be a plumber before going to college, so I am confident I can do this with little problem. However, I do have a question about what solder composition is best for this sort of thing?



Specifics:



* I plan to use 2/0 gauge welding cable

* I will be using a torch soldering method

* I am going to use eyelet style end connectors everywhere. Except of course for the jumper cables.



Looking on the McMaster-Carr website, there are a lot of different types of solder, mostly with differing levels of Tin/Lead composition. They give short descriptions as to the ideal uses for each type. So judging by their page, the ones that sound best suited to my needs are:



* 30 / 70 (Tin / Lead) - solder for torch soldering

* 40 / 60 (Tin / Lead) - general purpose dipping solder

* 50 / 50 (Tin / Lead) - general purpose, handles sheet metal and tinning work

* 60 / 40 (Tin / Lead) - most popular dipping solder for electronics



Oh, these are solid core solders. At the suggestion of a few folks in my previously mentioned thread, I am planning to use a type of flux that is electrically neutral and non-corrosive called Supersafe Superior #30.



So... any suggestions would be greatly appreciated.



Thanks all,

Tom

 

[illflem]

I would use the 60/40

 

[fest3er]

I would use a dielectric grease and crimp the connectors on.

I don't know of any high-current applications where connectors are soldered. Why? Because high current can cause high heat, and high heat melts solder.

Of course, jumper cables are rarely used to the point of high heat, so you can probably get by with soldering. But you should still crimp the connections first, then solder.

If you can get the solder to melt quickly enough, the 60/40 should be fine. Another possibility is to use a solder paste - impregnate the wire end with the paste, coat the connector with it, mate the two, and heat with torch. Don't forget to apply flux to both to ensure the solder sticks to both pieces.

Fest3er

 

[Shooter]

Originally posted by fest3er

I would use a dielectric grease and crimp the connectors on.



I don't know of any high-current applications where connectors are soldered. Why? Because high current can cause high heat, and high heat melts solder.

Fest3er

Always use a mecanical connection: be it a crimp or bolted splice but never solder as stated above. Use shrink over the splice.

 

[LandShark]

Here's what I did on my boat about 15 years ago. I made at least a dozen connections that are still good on a boat in use over 300 days a year.



I used marine grade (tinned copper) wire, with pre tinned heavy duty ring connectors. Put flux on the wire and connector, then assemble. Crimp the connector onto the wire, then solder the connection with 60/40 solid solder using a torch.



Crimping is the best electrical connection and the solder keeps the moisture and dirt out so it stays a good connection.

 

[PHaller]

When I bought my truck and saw 2 batteries I decided to add heavy ground cables made from 2/0 welding cable. I did not have a heavy duty lug crimmping tool.

I pre tinned the fine strands carfully using just enough heat to flow the solder so as not to make more then just the end of the cable inflexable. Then I heated the heavy duty lug with the torch and flowed rosen core 60-40 solder into the cup where the lead fits until it was almost full of molten solder and making sure it was adhered to the entire surface of the lug cup. I then continued to heat the lug untill very hot and plunged the pre tinned cable end into the lug. It flowed perfectly onto the tinned strands and did not flow into the cable making the very end inflexable. It turned out beautifully and has been in use for 8 years with no failures.

I aggree that a crimped lug would be better but I did it without any special tools and almost no cost. I have since found that if you buy the cable and the ends from a good welding retailer, they will begrudgingly crimp the lugs on the cable at the lenghts you specify if asked.

I would go for it with the soldered lugs and if you expereance a failure later, cut off the soldered lug and crimp on another.

As a side note, I always include another ground connection on all my vehicles so as to head off any strange to detect ground faults. As a certified mechanic for 20 years, I can tell you from experience that the ground links always seem to be overlooked as the root cause of a hard to diagnose and wierd electrical failures, especially in fuel injection and compture systems on vehicles.

Most PCMs will begin to exhibit strange electrical intermittant failures at about 10. 8 volts. So if you are experiencing some strange electrical ghost and can't find the cause, double check your ground path and if in doubt, add another.

-Paul R. Haller-

 

[SRadke]

60% lead 40% tin will have the lowest melting point. Probably want to stay away from that one.

Also, do not use an Oxy acetylene torch on copper. It reacts and creates a compound called copper acetylide that is very volatile.

-Scott

 

[ToolManTimTaylor]

Originally posted by SRadke

It reacts and creates a compound called copper acetylide that is very volatile.

-Scott

I thought that was Fosgene gas ????

 

[illflem]

Acetylide, also known as carbide salts, are formed when acetylene gas and silver or copper are combined, big boom! I'm sure if you go to a website to learn how the make it that Homeland Security will be following you for the next few weeks, it's a very powerful explosive.



Fosgene (phosgene) gas was the WMD of choice in WW I and is formed by putting a flame to freon refrigerant or to certain plastics, smells like fresh-cut grass. A couple whiffs will knock you dead but it takes a few days of misery first.

 

[jcbrown]

2% Silver-Bearing Solder...

I crimp, solder, and heat shrink using 62/36/2 silver-bearing solder.

 

[Huntmastr1]

It is common industry standard to SILVER SOLDER joints in COPPER tubing and pipe using an OXY/ACET torch.

 

[nickleinonen]

I don't know of any high-current applications where connectors are soldered. Why? Because high current can cause high heat, and high heat melts solder.

i can think of one, locomotive traction motor leads. some are crimped [newer ones] but there are some still out there with soldered leads, and the cables are pretty think on them [about 1. 25" diameter inc. outer shiething] and yep, i have seen them solder joints overheated causing the lug to separate from the cable [makes a mess of the lug & cable where it arc's across] and they can be up to 1200 amps

 

[Reddog1]

I have two sets of jumper cables (30 foot) I made over 20 years ago. I used 4/0 welding cable and the crimp method. The only problem I have had is with the ends, they just do not hold up.



What are you using for clamp ends?



Wayne

 

[TomGolden]

Hi Wayne,



I have found 2 sources so far for what appear to be decent jumper cable clamps.



* 800 amp extra heavy duty - $13 each from Waytek Wire



* 800 amp - $27 each from Wrangler Power Products



* 1000 amp - $60 each from Wrangler Power Products



I'm planning to go with the cheaper ones and hope I never melt them. $240 for just the clamps is a wee bit too $$$$$$$$$$$$$$$ for my blood.