Landracing Forum
Tech Information => Technical Discussion => Topic started by: SteveM on July 02, 2013, 01:26:13 PM
-
Thoughts on crimping versus soldering of battery terminals and cable ends?
We have a very large crimper at work (like the size of a big pair of bolt cutters), but I have always had a personal preference for metallurgical bonds like those achieved with soldering.
There's a lot of online support for crimping and heat shrinking, but it would be great to hear what you guys have to say.
Steve.
-
Steve;
A good crimp is OK. Bell Labs did research years ago on crimped wire connections and their conclusion was that a crimped connection was excellent as long as it was a gas-tight crimp. The wire and the ferrule needed to be crushed together so that they bond and do not allow entry of even gas into the ferrule. Eventually this will allow oxidation and corrosion.
A soldered joint is by its nature "gas tight" so that is not a problem. If you use rosin-core solder the joint will be OK but an acid-core solder will leave residue that can't be cleaned out of the wire strands. Due to solder wicking up between the wire strands, the wire will be made stiff for some length from the soldered joint-- don't allow vibration to flex the wire or it will fatigue and break around that point.
Regards, Neil Tucson, AZ
-
For what t is worth.
In 2011 I had crimped cables. When I disassembled the car I noticed salt water had wicker up about 1/4 of the strands on 1/0 wire as high as 1 inch. When I peeled back the insulation the copper was green and nasty. It was hidden other than cutting the insulation off of the cable. I replaced all of the 1/0 cables this year with soldered ends and adhesive heat shrink tubing. I think the good thick adhesive lined shrink tubing is the trick. My hope is it will keep the wet salty moosh from wicking up the cable strands. Also using rubber cable end covers over the 1/0 terminals. I thought about coating the copper terminals, nuts and studs with dielectric grease to ward off the salt gremlins.
BR
-
Steve,
The biggest problem with the average guy crimping wires into lugs is that they usually don't have access to the right tools for the job. You want to use tools made for the job, like T&B (Thomas &Betts) or other tools that are made specifically for Electricians. Over the years I have used hydraulic and manual presses for lugs from 750 MCM wire size on down, and never ever had any problems with the wire or lugs. For Bonneville you would want to put heat shrink tubing over the lugs and wire to protect it from moisture.
If I did not have access to the right tools I would solder the joint. For a Battery I would only use welding cable wire. JMO.
Tom G.
PS. I forgot to say that I am not a fan of V type crimpers, the kind that push a V into a V receiver that you can buy from any specialty automotive store. I personally like the type that take a die for the specific size wire you are crimping. They usually have four or more sides and creates a circular pressure from the outside to the inside of the lug. Once again JMO.
-
The crimping tool we have should be up to the task of making a good crimp. I don't think the tool will be the limiting factor.
It's a Penn-Union TDM-250...
(http://i468.photobucket.com/albums/rr44/Jetmugg/Dodge%20Rampage/crimper_zpsd5f37d74.jpg) (http://s468.photobucket.com/user/Jetmugg/media/Dodge%20Rampage/crimper_zpsd5f37d74.jpg.html)
Standard set of sheetmetal snips shown for comparison.
I'll be using some #1 welding cable (ultra-fine strands). The only way I'm familiar with soldering a lug like this is to place the lug, open end up, in a vise, and melt the solder into the lug, then jam the end of the wire down into the liquid solder.
In either case, I will definitely invest in some of the rubber, adhesive heat shrink tubing.
-
My training in soldering is for ham radio - small gauge wire - but it still is clear that it's necessary to heat the work (wire and terminal/lug), not just the solder, to get a properly-made joint. You'll have a hard time, no doubt, in getting the heavy wire hot without melting the insulation. But pushing the cold wire into hot solder will likely not give very good adhesion of the solder to the wire - and corrosion can be the result.
-
Either way think about using clear with glue heatshrink. If you see green you have a problem. If you are going to crimp look into Kopr-Shield from Thomas and Betts. Same theory as die electric grease but it claims to aide connectivity. Tin plated battery cable from a boat shop or ebay can reduce corrosion.
Gary
-
I tryed to solder a battery cable and clamp for a friends mini back hoe the problem that i had was getting the cable hot enough to get the solder to flow into the cable but it was to hot for the clamp and it melted. We ended up using a clamp where you slide the wire under a flat plate and tighten a bolt on either side of the plate to hold the wire in place. I agree that melting solder into a clamp and then shoving a cold wire into the hot solder is not the way to go. Why don't you just have some battery cables custom made by a pro.
-
Usually those big lugs meant to be soldered onto the wire are cup- type. This keeps the solder from just running out the open end of ordinary lugs. If you melted a terminal (Lug... whatever you call them) it was WAY too hot. Solder melts at around 650F. A 63% solder alloy is optimum for electrical work.
A huge old-fashioned soldering iron would work, if you can find one. 200 watt irons aren't too common these days. A small propane torch works well but oxy-acetylene is too hot.
Regards, Neil Tucson, AZ
-
The crimping tool we have should be up to the task of making a good crimp. I don't think the tool will be the limiting factor.
It's a Penn-Union TDM-250...
(http://i468.photobucket.com/albums/rr44/Jetmugg/Dodge%20Rampage/crimper_zpsd5f37d74.jpg) (http://s468.photobucket.com/user/Jetmugg/media/Dodge%20Rampage/crimper_zpsd5f37d74.jpg.html)
Standard set of sheetmetal snips shown for comparison.
I'll be using some #1 welding cable (ultra-fine strands). The only way I'm familiar with soldering a lug like this is to place the lug, open end up, in a vise, and melt the solder into the lug, then jam the end of the wire down into the liquid solder.
In either case, I will definitely invest in some of the rubber, adhesive heat shrink tubing.
I have crimped envy! I buy heat shrink from these guys, http://www.buyheatshrink.com/ (http://www.buyheatshrink.com/)
They sell is in bulk lengths. I buy it cut to 4' lengths. They have thin wall, heavy wall with or without adhesive.
Just in case some is looking for a good source.
BR
-
My preference is to crimp, then solder and then use a heat shrink rated for underground usage.
The crimp creates a mechanical connection the solder fills the voids and creates a bond and the glue in the heat shrink makes it water proof.
This is how we repair broken under ground wires.
If you only crimp and do not solder make sure to coat the wire and fitting with an oxide inhibiter.
Don
-
My preference is to crimp, then solder and then use a heat shrink rated for underground usage.
I agree.
Either one by itself will create the necessary area of contact for electrical flow with zero resistance. Protection against corrosion is mandatory.
If it's done right. The number of ways you can screw this up is infinite, based on what I have seen professionals, and jerks that think they are pass as fine work.
Check the temperature of the terminal and wire after a run. If it isn't at ambient, then something is wrong.
The boat guys have been fighting this for as long as electrical circuits have been around.
Solder vs. Crimp: National Marine Electronics Association standards state that solder shall not be the sole means of mechanical connection in any circuit (with the exception of certain-length ship's battery cables). If inclined to add solder to a lug terminal, solder it after you apply the crimp. A good solder joint is bright and shiny.
If you see corrosion on the wire replace the wire. Don't screw around with cutting back to "good" wire.
A bad solder joint or crimp joint looks like . . . Oh, hell. Do the homework.
-
Good discussion!
Any tips for crimping and soldering, especially on battery-sized cables? For smaller wires, this is much simpler.
Here's my proposal for larger (i.e. #1 or larger)....
1) Flux the end of the wire before crimping.
2) Crimp it
3) Heat the crimped connector with a propane torch, while keeping the nearby insulation cool by wrapping with a wet rag.
4) Feed in the solder
5) Heat shrink tubing. I like the idea of the clear heat shrink, to see if there's any funny business going on.
-
Make SURE that the flux is not acid- based-- that guarantees corrosion. Plumbing stuff is usually acid flux.
Regards, Neil Tucson, AZ
-
I'll go check the stash in the engineering dept. :-D
-
I prefer the solid end lugs to hold the solder. I also use a small butane torch for more localized heat. Lots of great tips here though.
-
The clear heat shrink has no sealant in it and thus is not water proof.
I would recommend a heat shrink made for underground usage that has sealant in it.
Also, it seems to help if you slide the heat shrink on the wire before attaching the lugs ( don't ask how I know). :roll:
Don
-
I admit clear with glue is not very common, I got the reference from an engineer at a jet engine company. I don't know if it is approved for underground but I have had good luck with this http://www.heatshrink.com/heat_shrink_tubing/w3c_4ft.asp
Gary
-
I admit clear with glue is not very common, I got the reference from an engineer at a jet engine company. I don't know if it is approved for underground but I have had good luck with this http://www.heatshrink.com/heat_shrink_tubing/w3c_4ft.asp
Gary
Looks like it should work.
Thanks, Don
-
There is definitely clear heat shrink with sealant in it. However I don't like to leave a gap where the cable goes into the terminal. Over time, it seems to me that if you leave a gap, that is always where the heat shrink starts to wear through or split. They sell the extra thick sealed stuff where I usually buy wiring supplies. That is what I like to use on batteries.
http://www.wiringproducts.com/electrical-supplies/heat-shrink-tubing/heavy-duty-heat-shrink-with-adhesive
-
The way I solder heavy gauge wire and terminal lugs is as follows:
I use a MAPP gas torch, you want plenty of heat so you can do it quickly before everything gets heat soaked (especially the cable)
Have a plastic spray bottle close by, full of water and set to produce a spray that is almost a solid stream (so you can control what you squirt the water on with a bit of precision)
A junk cotton rag soaked with water is also handy to have close by.
Clean both the cable end and the inside of the terminal so they are bright.
Slide a length of heat shrink tubing over the cable end and slide it back a couple feet so it won't get too hot while soldering.
Paint the cable end and the terminal lug with some zinc chloride soldering flux.
Heat and tin the cable end -- you don't want to over heat it and melt back the insulation too much, just get a thin coating of solder on the outer surface of the cable end.
Pull the heat away immediately when you get a bright coating of solder on the cable end.
(a quick wipe with the wet rag down the insulation of the cable moving toward the cable end helps to avoid the insulation curling back and pulling away from the hot end of the cable)
After it has cooled enough to handle, dress the end of the tinned cable so it has no rough spots and is a snug but sliding fit in the cold terminal, put a bit more soldering flux on it and set it near the vice.
Put the terminal in a vice with two pieces of wood or masonite clamping the lug end so the vice does not suck all the heat out of the terminal.
Heat and tin the terminal. A bit of aluminum foil with a slit in it slid over the terminal and vice jaws will cut down heating of the vice and smoking of the wood pads)
As soon as it is hot enough for the solder to flow, stuff the cable end in the terminal and start feeding solder to the upper end of the terminal (cable end) as you apply the hottest part of the torch flame to the lower end of the terminal and end of the cable. (this takes 3-4 hands so recruit a helper if you can to handle the cable while you handle the solder and heat.)
This causes the solder to wick down toward the hotter terminal and the melting solder acts to cool the standing end of the cable slightly so the body of the cable does not get quite so hot and curl back all the insulation..
As soon as the solder forms a drop on the bottom of the terminal and bitter end of the cable (completely closing off the ends of the strands), pull the heat away and hold the cable very still as the solder chills.
As soon as the solder changes from shiny to mat gray and starts to solidify, take a squirt bottle of plain water and start cooling the lug end clamped in the wood to start drawing heat out of the joint without heat shocking the joint too much by avoiding shooting the water directly on the soldered end of the lug.
Once the joint is cool and dry, clean with a brass brush and alcohol until it is free of soldering flux, and let dry completely.
Paint it with liquid electrical tape, and let it dry.
Slide the heat shrink tubing over the fitting and shrink it.
(you did remember to slide the heat shrink sleeve on the cable a couple feet back so it would not get hot and set while soldering didn't you?)
Paint the end of the cable and the joint ends of the heat shrink tubing with the liquid electrical tape just to be sure it is completely sealed.
If you are really paranoid wrap this with rubber electrical tape or the new self sealing silicone electrical tapes which will self bond into a solid cover after it sets for a while.
Larry
-
I've used "liquid" electrical tape to good advantage for a few things, although I've never put it on a main battery terminal. The stuff works, though. We make connections/repairs on the lighting wiring for the rear lights on our big trucks -- and the connections stay good through winter after winter. Another use was for the thermocouple that we use to measure water temp in the hot tub. The first 'couple died within a few days of being installed and left underwater continuously. No doubt in my mind that water got into the connection and crudded up the junction. So for the next one I coated the last inch or so of the wire and the thermocouple itself -- and here we are, a year later, and no diminution of accuracy has happened. It still works after a year of continuous immersion in hot water.
It's not a cure all -- but certainly worth having on the shelf in your shop.
-
Larry;
I'll agree with everything you posted except the "zinc chloride soldering flux". This is a corrosive flux that will, over time, corrode the copper wire and fail. Stick to a "Radio" flux-- it is rosin based and can be cleaned off with any common solvent. It does not leave a corrosive residue.
Regards, Neil Tucson, AZ
-
WOW - great discussion with plenty of detailed recommendations! Threads like this are incredibly valuable to newbies like me. Thanks again.
I still haven't made up any battery cable terminations, but will be in the near future.
Steve.