replacing battery wing nuts with nylok nuts

[BrentB]

I am replacing the wing nuts with nylocks and lock washers. Interesting while shopping and looking at new batteries and some had them. Was it mandated to battery makers to change over?

[mcc272]

I have always heard that Nyloc nuts should not be used in electrical systems and that conventional nuts and lock washers were prefered. I don't know where I picked this up but the theory is that the nylon insert in the nut insulates the nut from the post. The objective is the best electrical connection between the lug and the post. The issue is how much of the circumference of the hole in the lug connects with the post. If there is a marginal connection between the lug and the post, perhaps due to a lug with an oversized hole, the flat of a conventional nut pressed tightly against the lug carries current through the nut and its threads helping to establish a good electrical connection to the post. A Nyloc nut does not improve the electrical connection.

There are others on the site such as Joe (Seawolf) and Dr. Bob who have much greater electrical backgrounds than I do. I would be interested in their thoughts on this subject.

As to wing nuts, I believe that the theory is that you can more properly torque a hex nut than a wing nut and, as a result, there is a lower chance of the hex nut loosening.

[Captains Cat]

I concur with Jim. I think we've all jumpstarted a car or something in our lifetimes and put the jumper cables on the battery. You need a big conductive thing for the clamps to affix to and a nut with a nylon insert isn't it. You can get plenty of holding power with a flat washer, a lock washer and a tightened up hex nut. I don't use wingnuts (although I may have been accused of being one at some point in my lifetime! )

Charlie

[thataway]

Flat washers, lock washer, and then a standard nut. Nylox can melt under the heat at a terminal. [/u]

[Fairbro]

As I have preached before I preach again. Coming home a couple of nights ago I noticed my tach on the starboard motor dropped to zero and then picked up again when I moved the throttle. Having experienced this problem before to the tune of several hundred dollars, to replace my charging coil, I immediately removed all of my ground battery cables, emory clothed them, dielectric greased them, and re-tightend the wing nuts with a pliers. No problem so far after 6 more hours. Whether wing nut or regular nut: Clean them and tighten them without mercy to prevent costly repairs. A bouncing or dead tach is the first sign of a loose battery ground in an outboard motor and the precurser to expensive repair!

[Sea Wolf]

As far as this wing-nut knows, all the advice is right on so far!

If you're really concerned with a high amperage connection, like on the starter circuit for a diesel motor, use copper nuts, washers, and lock nuts.

Don't forget the dielectric grease in any case, as the washers and nuts will be particularly prone to corrosion around battery acid vapors and also being "charged" by the battery's voltage.

Joe.

[Almas Only]

I use nylok nuts, and would appreciate any reference to an authoritive source which has documented instances of the nylon melting, and allowing otherwise tightened nuts to come loose.

It seems to me that you would have to be dealing with a major electrical fault before generating enough heat at the post to melt nylon, and in that case, tightness of your connection at the battery would be the least of your worries. This is particularly so given the fact that the nylon does not contribute materially to the tightness of the nut, but only to keeping it in place should it otherwise tend to vibrate loose. All the work in a properly tightened nut (believe the standard is 10 ft. pounds) is done by the first one or two threads, which in this application, are stainless steel.

I'm all for bombproofing, but am curious to know if discarding nylok nuts is overkill.

[Levitation]

I spent much of my wasted youth maintaining industrial plants... No plastic fastener for high current battery cables would be accepted in that industry...
The problem is not whether the plastic nut is an insulator - that is immaterial... It is that plastics will creep under load and elevated temps, giving up a little tension, causing the connection to increase resistance slightly, making the connection run hotter, and so on in a vicious circle...

[Rick from Maine]

I think that Nylok Nuts are the right way to go for the following reasons:
1. The electrical connection is independent of the nut in that the conductive surfaces are the flat faces of the battery terminal and wire lugs. The nut compresses/clamps those faces together to ensure resistance free conduction. The type of nut, whether wing nut or self locking, has no influence on the clamping force of the mating electrical parts.
2. The Nylok element is not a structural part of the nut and joint and has no influence on the electrical connection. It only provides resistance to turning so that the nut won’t vibrate loose. Once properly tightened, the Nylok nut will stay tight. This may not be true with wing nuts, or wing nuts combined with locknuts if there are washers in the joint.

For what it's worth, Rick from Maine

[Nunya]

I switched over to nylocs years ago. Use a flat washer underneath and have never had a problem. Most of my boating buddies have done the same. I had issues with wing nuts getting loose.

[AstoriaDave]

Listen carefully to Levitation.

A short in the circuit (major electrical fault) is not required to get a hot spot at the battery/cable connection. It is the locally high resistance of a loose connection that contributes to a local hot spot. Nylon need not melt to lose its effectiveness at ensuring the nut stays tight; it only must he warmed near its yield point.

Check out Nigel Calder's references on how to attach cables to battery terminals: compatible metal nut and lock washer, tightened so that they do not compress any plastic shrink tubing (which can also slowly migrate and loosen the connection).

[Matt Gurnsey]

We throw away the wing nuts that come with the battereis we sell away, and use wahser, lock washer and nut.

[BrentB]

thanks

Sometimes you feel like a nut
Sometimes you dont
Peter Paul Almond Joy's got nuts Mounds don't


Sometimes you dont use wingnuts
Sometimes you do

[DaveS]

I've met a few wingnuts, don't much care for them.....

(and Charlie, even though you claim that you may have been referred to as one in the past, I certainly don't believe that, because I've met you and you absolutely don't fall into that category!)

[thataway]

The one case I saw where the nylon melted was in a diesel vessel, and an 8 D battery. Granted that this is not a C Dory, but the same conditions of corrosion can exist in our boats. The Nylon on the battery terminal is not to ABYC standards. Also remember that Nylon insert nuts are designed to be used only one time--then discarded and replaced.

If you use wing nuts, then tighten them appropiately with a wrench or pliers--just hand tight will not be adequate--and I also discard them, unless it is in a pinch and I don't have the appropiate size nuts. The reason for a washer, is that many times I find cables which have the end fittings with too big a hole for the posts (for example, although it used to be the standard of 3/8" and 5/16" posts--now one finds batteries with only 5/16" posts. Also often if you clamp down directly on the terminal, there is enouugh leverage to start the bolt unthreading, if there is no washer--no matter if you have torqued it properly (frankly I could not get any torque wrench I own into the battery compartment of any of my C Dories).