There may be a complex, microscopic explanation. But the short answer I picked up as an ME and in years of being a technical trainer is that the action of crimping, staging, etc. to get a tight connection forces the dielectric out of the way and gives connectivity through metal to metal contact. The dielectric remains in the voids between wire and fitting (or screw and mast) and among the wire strands to prevent incursion of moisture and atmosphere that cause corrosion.
Rick Brass Sent from my iPad > On Aug 14, 2019, at 12:52, Dennis C. via CnC-List <cnc-list@cnc-list.com> > wrote: > > This question has been asked before. Yes, it seems counter-intuitive that a > Teflon or silicone coating would conduct a current. I vaguely recall one of > the more technically oriented listers answering the question about 15-20 > years ago. Something about the interstitial spaces being coated at a > microscopic level and the electrons aligning in lockstep or something. I'm > not being facetious, it really was something like that. > > All I know is it works. Like you, I've measured ohms before and after > application of Tefgel with little change indicated. > > Dennis C. > Touche' 35-1 #83 > Mandeville, LA > > >> On Wed, Aug 14, 2019 at 11:23 AM Josh Muckley via CnC-List >> <cnc-list@cnc-list.com> wrote: >> Dennis, >> >> This question came up at work the other day. I do the same as you, coat the >> connections then attach. Battery manufacturers and, in my case, the PM >> schedule for batteries at a nuclear power plant both state scrubbing the >> connections, coating them, wiping clean, then making the connection. In >> this case they are using silicone dielectric grease but the concept is the >> same. In my own practice I really don't bother to wipe the connections >> clean. The question is, if the Tef-gel and Silicone are both dielectric >> (non-conductive) and cover the mating surfaces then how is the electrical >> connection made? Why does it not increase the resistance of the connection >> - or does it, but just to an insignificant extent? My ohm meter reads zero. >> I've smashed the grease into electrical connectors and even outlets for >> weather, water, and corrosion protection with absolutely no indication of a >> problem and always assumed that the metal to metal interface just punched >> through the dielectric and that any insignificant increase in the resistance >> must be dwarfed by that of the risk of corrosion. >> >> Are you aware of any resistance tests being done or of devices capable of >> detecting if ultra-low resistance is being created? >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Solomons, MD >> >> >> >>> On Wed, Aug 14, 2019, 11:48 AM Dennis C. via CnC-List >>> <cnc-list@cnc-list.com> wrote: >>> Superlube will NOT work. >>> >>> I put TefGel on all metal to metal contact points. That is, before I crimp >>> a connector on a wire, I coat the wire with TefGel. Then I coat the ring >>> connector or male/female disconnect with TefGel before attaching it to a >>> terminal block, breaker, or whatever. >>> >>> My buddy and I have about 40 years of collective experience in marine >>> electrical. Neither of us has ever had a corrosion related failure on any >>> connection coated with TefGel. >>> >>> TefGel is also a good dissimilar metal corrosion coating. We use it, or >>> threadlocker, on any stainless into aluminum fastening. >>> >>> Dennis C. >>> >>>> On Wed, Aug 14, 2019 at 10:24 AM Wade Glew via CnC-List >>>> <cnc-list@cnc-list.com> wrote: >>>> Dennis, >>>> Do you put the TefGel on the battery connecting surfaces or coat the >>>> surfaces after all connections are made? Would Superlube work the same? >>>> Wade >>>> Oh Boy C&C 33 MKII >>>> >>>>> On Tue, Aug 13, 2019, 13:47 Dennis C. via CnC-List, >>>>> <cnc-list@cnc-list.com> wrote: >>>>> Best to disconnect all the battery cables both positive and negative, >>>>> clean them and reconnect them. Get yourself some Ultra Safety Systems >>>>> TefGel >>>>> (https://www.jamestowndistributors.com/userportal/show_product.do?pid=546) >>>>> and coat the connections with it. Clean both ends of the cables. >>>>> >>>>> Like Fred said, measuring voltage is only part of the story. You're >>>>> really looking for current. A corroded connection may show adequate >>>>> voltage but may be incapable of passing enough current to start your >>>>> engine. >>>>> >>>>> Dennis C. >>>>> Touche' 35-1 #83 >>>>> Mandeville, LA >>>>> >>>>>> On Tue, Aug 13, 2019 at 1:34 PM Wade Glew via CnC-List >>>>>> <cnc-list@cnc-list.com> wrote: >>>>>> thanks you. >>>>>> >>>>>> Ok, I'll get a volt meter to check the batteries directly. >>>>>> if I'm to check all the grounds, I take this to mean: follow the >>>>>> batteries back to wherever the system grounds to the engine block to >>>>>> begin with. Then each of the battery terminals and finally to where the >>>>>> battery banks come to the main ground bus? I'm really a rookie with >>>>>> electrical stuff so be specific if you can. >>>>>> >>>>>> Wade >>>>>> Oh Boy C&C 33 MK II >>>>>> >>>>>>> On Tue, Aug 13, 2019 at 1:14 PM Frederick G Street via CnC-List >>>>>>> <cnc-list@cnc-list.com> wrote: >>>>>>> Agreed, sounds like a bad ground. Voltage is one thing; but enough >>>>>>> current to crank is another, and definitely something that will be >>>>>>> adversely affected by bad ground continuity. >>>>>>> >>>>>>> — Fred >>>>>>> >>>>>>> Fred Street -- Minneapolis >>>>>>> S/V Oceanis (1979 C&C Landfall 38) -- Bayfield, WI >>>>>>> >>>>>>>> On Aug 13, 2019, at 12:39 PM, Dennis C. via CnC-List >>>>>>>> <cnc-list@cnc-list.com> wrote: >>>>>>>> >>>>>>>> Clean all the ground connections. >>>>>>>> >>>>>>>> Dennis C. >>>>>>>> >>>>>>>>> On Tue, Aug 13, 2019 at 12:26 PM Wade Glew via CnC-List >>>>>>>>> <cnc-list@cnc-list.com> wrote: >>>>>>>>> Hello listers, I would appreciate any advice you might have on my >>>>>>>>> electrical issue du jour. >>>>>>>>> >>>>>>>>> Mine is a C&C 33 MK II and I have a Link 20 battery monitoring >>>>>>>>> system. Bank 1 (house) is 4 Trojan T-105 (225 AH) 6V deep cycles >>>>>>>>> about 5 years old. Bank 2 is a 12V starter battery dated 2005. I >>>>>>>>> look after my batteries pretty well and the system seemed to be >>>>>>>>> operating normally. I have a True Charge 40 battery charger. One >>>>>>>>> morning after several days out sailing, drinking lots of cold beer >>>>>>>>> from the fridge and lots of music playing) and running the engine >>>>>>>>> very little, the engine would not start. Starter turned slow, felt >>>>>>>>> like no battery power. I had the Master Switch on 1 so I turned the >>>>>>>>> switch to Battery 2 at which point all 12V electrical activity on the >>>>>>>>> boat stopped working altogether. Prior to switching to Bat 2, the >>>>>>>>> Link 20 showed my starter battery at 12.4V with estimated time on >>>>>>>>> battery remaining at 225 hours. I put a portable battery pack onto >>>>>>>>> my starter battery and it read 12.4 V from the battery. However, >>>>>>>>> powering up the battery pack and connecting to my starter battery >>>>>>>>> allowed me to start the engine. >>>>>>>>> >>>>>>>>> I went back to harbour and replaced my starter battery with a brand >>>>>>>>> new 1000 cranking amps 12V battery. I charged by shore power >>>>>>>>> overnight then left for a few more days on the water. >>>>>>>>> >>>>>>>>> Now, the current circumstance is this. >>>>>>>>> When connected to shore power and Main Switch set to Bat 1, I see >>>>>>>>> normal charging voltages to both battery banks. >>>>>>>>> When under engine and Main Switch set to ALL, I see normal charging >>>>>>>>> to both batteries. >>>>>>>>> After sitting overnight on anchor, I see both Bank 1 and Bank 2 are >>>>>>>>> resting at about 12.5 V. Both banks show plenty of reserve on the >>>>>>>>> Link 20. When I try to start the engine it feels again like I have >>>>>>>>> low battery power. The engine barely turns when I set the Main >>>>>>>>> Switch to either Bat 1 or ALL and won't start. If I change the >>>>>>>>> switch to Bat 2, all 12V electrical activity on the boat instantly >>>>>>>>> stops. If I put the portable battery pack onto my starter battery >>>>>>>>> with the switch in the ALL position, the engine will go however, it >>>>>>>>> still feels like the starter is turning too slowly. >>>>>>>>> >>>>>>>>> I'm looking for a single cause to explain all this as up til now, the >>>>>>>>> system has functioned well for the 10 years I've owned the boat. I >>>>>>>>> would appreciate any suggestions >>>>>>>>> >>>>>>>>> Wade >>>>>>>>> Oh Boy, C&C 33 MK II >>>>>>> _______________________________________________ >>>>>>> >>>>>>> Thanks everyone for supporting this list with your contributions. Each >>>>>>> and every one is greatly appreciated. If you want to support the list >>>>>>> - use PayPal to send contribution -- https://www.paypal.me/stumurray >>>>>> _______________________________________________ >>>>>> >>>>>> Thanks everyone for supporting this list with your contributions. Each >>>>>> and every one is greatly appreciated. If you want to support the list - >>>>>> use PayPal to send contribution -- https://www.paypal.me/stumurray >>>>> _______________________________________________ >>>>> >>>>> Thanks everyone for supporting this list with your contributions. Each >>>>> and every one is greatly appreciated. If you want to support the list - >>>>> use PayPal to send contribution -- https://www.paypal.me/stumurray >>>> _______________________________________________ >>>> >>>> Thanks everyone for supporting this list with your contributions. Each >>>> and every one is greatly appreciated. If you want to support the list - >>>> use PayPal to send contribution -- https://www.paypal.me/stumurray >>> _______________________________________________ >>> >>> Thanks everyone for supporting this list with your contributions. Each and >>> every one is greatly appreciated. If you want to support the list - use >>> PayPal to send contribution -- https://www.paypal.me/stumurray >> _______________________________________________ >> >> Thanks everyone for supporting this list with your contributions. Each and >> every one is greatly appreciated. If you want to support the list - use >> PayPal to send contribution -- https://www.paypal.me/stumurray > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray >
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