The Proper Use of Dielectric Grease?

Discussion in 'The Garage' started by Streamin' E, Dec 15, 2009.

  1. Streamin' E

    Streamin' E Half-assed adventurer

    Joined:
    Oct 24, 2002
    Oddometer:
    1,448
    Location:
    Carefree Highway
    Can anyone comment on it's proper use/application? I assumed you'd use it to spray electrical plugs/contacts before reassembly to prevent oxidation. However, being that it's nonconductive (smells just like silicone spray to me) I'm left wondering. Anyone care to chime in? Thanks!
    #1
  2. johnjen

    johnjen Now, even more NOW!…

    Joined:
    Nov 28, 2001
    Oddometer:
    17,035
    Traditionally dielectric grease is used to 'seal' connections from water and other potentially corrosive environments. This is good because in those situations it lengthens the life of the connectors (and the rest of the electrical circuits) considerably. Marine uses are probably the most common for this type of 'solution'.

    Motorcycles, while subjected to lots of water etc. generally don't come with connectors that lend themselves to the use of dielectric grease. That doesn't stop some from using it however.

    I generally don't like it on motorcycles for several reasons, mostly because it makes a huge mess. The grease will leak out and get on everything in its vicinity over time. And once the grease coats any surface, it will attract dust and dirt and then accumulate it, thus the mess. And once the dirt and dust are mixed into the grease you really don't want it to then get into the connections themselves.

    Also cleaning up the connectors once the grease has been added to them, while possible, is really time and labor intensive. So much so that it's a major PIA if you have to trouble shoot a problem, repair a cable or connector, or even modify a cable to add functionality. And once the grease gets on your hands, it then gets on everything you touch…

    Now if you're not going to hold onto the bike for more than a few years it probably won't be a big deal to you, but the next owner will probably exhaust his collection of 'colorful language' when he dives into the wiring harness.

    Can you tell I think dielectric grease is solution looking for a problem that doesn't exist? :nod

    Now if what you seek is contact enhancement, that is a whole other topic.

    JJ:gerg
    #2
  3. the_gr8t_waldo

    the_gr8t_waldo Long timer

    Joined:
    Feb 28, 2006
    Oddometer:
    2,743
    Location:
    tacoma warshington
    i've never run across the spary product, but it would stand to reason that it has to be thinned out in order to allow it to pass thru a spray nozzel. sounds like it would make a mess, even if you could control the overspray. i've only used the stuff that comes a toothpaste type of container. after about 7 years of use and i haven't noticed any dirt collecting on the nominal excess blobs. i use a really small screwdriver to apply the grease on the lil spade connectors in the white nylon multipin connectors. i also use it when making chrimp style connections. before chrimping i dip the bare wire into some grease(just enought to coat the wire) and then insert the wire and chrimp. the excess grease gets sueezed out and the remainder is packed inside the barrel. this will exclude water from entering. aside from keeping moisture from the mateing surfaces inside of a mulitpin connector, it will lube the mateing surfaces so that next time you take it apart, it will take considerably less effort than the last time you did this. i get die-electric grease for free from work( left over packets from high voltage terminations). but when it comes to actually puting my own money out, i just buy "super_lube" yeah it's not the same. but it's close enough! it's about 8$ for a 3oz tube compaired with the typical autostore condiment pack, it's dirt cheap. and has a lot of uses, that require something that will not attack rubber or plastics.
    #3
  4. DRONE

    DRONE Dog Chauffeur

    Joined:
    Oct 1, 2007
    Oddometer:
    9,348
    Location:
    Tacoma - ish, WA
    I like to add electrical accessories to my bikes (see my sig thread) and I use Posi-locks and Posi-taps quite a bit. They let me change things around easily and have been reliable connectors for me. YMMV. I use a tiny dollop of Di-grease straight out of the tube and into the cavity of the posi before I screw the halves together. No muss, no fuss.
    #4
  5. dtysdalx2

    dtysdalx2 Just glad to be here.

    Joined:
    Aug 1, 2004
    Oddometer:
    26,886
    Location:
    Moneyapolis, MN
    I noticed on my old Yamaha that DOESN'T have sealed connectors that they will attract mud, dirt and dust with dielectric grease. Right off hand I think you could wrap them with electrical tape to keep the dust & dirt out. Or update all the connectors with late model sealed connectors ($$$).

    There is a spray can too of the stuff... CRC makes it. I has one!
    #5
  6. Yossarian™

    Yossarian™ Deputy Cultural Attaché

    Joined:
    Jul 9, 2007
    Oddometer:
    12,855
    Location:
    the 'Ha
    The dielectric grease I use comes out of a tube, not a spray nozzle, and is a thick, clear gel-like substance. I used it on electrical connections like headlight prongs, etc. Motorcycles vibrate and shake a lot. This tends to cause electrical connections to loosen, and once they loosen a bit you will get electrical arcing between the components. This arcing causes oxidation -- the black "electrical burn" marks you see on some connectors -- which eventually causes the connection to fail.

    The grease displaces oxygen, so if arcing does occur, then there is no buildup of the black oxidation. Your connections live on. Your headlights stay on, your ignition remains operative.
    #6
  7. Streamin' E

    Streamin' E Half-assed adventurer

    Joined:
    Oct 24, 2002
    Oddometer:
    1,448
    Location:
    Carefree Highway
    I purchased a CRC aerosol product from Grainger. As mentioned the aerosol does makes it difficult to be selective with the coating. I was considering spraying a little into the cap and using an acid brush to coat the various surfaces.

    Sounds like a little will go a long way and also help to prevent dirt and grime buildup as johnjen mentioned.
    #7
  8. MCMXCIVRS

    MCMXCIVRS Long timer

    Joined:
    Nov 13, 2006
    Oddometer:
    1,674
    Location:
    Calgary, Alberta, Canada
    I mainly just use it on the spark plug boots. The grease helps to lubricate the rubbers so they slip on easier and prevents them from sticking to the ceramic so they will come off easier as well. I also sometimes use a light wipe to lube the rubber seals of watertight electrical connectors for the same reasons. A little goes a long way.
    #8
  9. bisbonian

    bisbonian Long timer

    Joined:
    Nov 8, 2007
    Oddometer:
    1,516
    Location:
    Tucson, AZ
    Take this as you will, no relation to me.

    As written by Wayne Orwig, MGNOC Georgia State Rep.

    Using Dielectric Grease on connectors.

    A lot of people use dielectric grease on connectors. Some people mistakenly believe that dieletric grease is a conductor. In fact, it is just the opposite; it is an insulator. Dielectric grease is typically made of silicone grease.

    As an insulator, dielectric grease is good for use on spark plug boots. This was one of the original applications on vehicles when the high-energy ignition systems came out. It can help insulate the connector and, in particular on a motorcycle where it can get wet, it waterproofs the spark plug boot. And, because it is silicone, it is fairly stable at high temperatures and won't affect the rubber and plastics.

    So why would you put an insulator on a connector? The idea is that you use a thin layer. When you push the connector together the grease is pushed out of the way enough to get a connection and the surrounding grease then keeps out water and oxygen. The connector will be protected from the environment and less likely to corrode. Plus, the silicone is safe for the plastics and PVC insulation.

    That sounds good, so far; so why not smear it on everything? Well there are a number of good reasons.

    First, silicone grease outgases constantly. If the silicone gas gets near a connector or a contact, such as a relay, and there is a spark, the spark at the contact can create silicon dioxide. Some people even suggest that the silicone gas from dielectric grease can travel many feet through the unsulation on a wire and damage a contact on the other end. Omron states that even their sealed switches can be damaged by nearby silicone grease outgassing. Reference the following links for more info:

    http://www.omron.com/ecb/products/pdf/en-d2vw.pdf

    http://machinedesign.com/article/lubricating-electrical-switches-1025

    Second, it is an insulator. It can prevent contacts from touching. If you do use it, use a very thin layer.

    Third, if you have a corroded connection, silicone grease will not help. In fact, it may make it worse. It can never improve anything. Dielectric grease will never make a poor connection better.

    Fourth, it attracts dust and dirt and it hardens over time. This means that if you smear a lot of silicone grease on connectors you may see nearby relays, switches, or points fail later on. Since silicone grease does nothing at all to improve the connection and, in fact, may insulate the contacts in the connector increasing the resistance the connector may still fail.

    So what do you do? Look for a contact enhancer/lube. While most contact cleaners are simple solvents that just wash the connector off there are contact enhancers that deoxidize the contact surface and actually work to lower the contact resistance (make a better connection). Most contact enhancers leave a lubricant behind that protects the metal and continue to deoxidize the metal and improve the connection. They can work to lower the resistance and make a better contact as time goes by. The best you can hope for from dielectric grease is that it seals it enough to not get worse. I have used Caig Deoxit on my bikes for a few years now. I first found out about this on my job when I had to correct an issue in a connector system that could not tolerate even 5 thousandths of an ohm of resistance drift. We had a connector in the field that had been improperly plated and was starting to drift, mostly in warm humid areas like Florida. Our testing showed that the Caig Deoxit could be a good long-term fix. We ended up using the Deoxit to stabilize the bad units until we could get corrected wiring harnesses built with the correct connectors. We also put a layer of Deoxit on the new parts to protect and keep them clean over their lifetime. This solved the drift issue that we had.

    I still use a small amount of silicone grease on my spark plug caps. It helps to waterproof them and makes it easier to pull the cap off, but I use it in very small amounts and never near a relay or switch.
    #9
  10. dtysdalx2

    dtysdalx2 Just glad to be here.

    Joined:
    Aug 1, 2004
    Oddometer:
    26,886
    Location:
    Moneyapolis, MN
    +1

    Yeah, what the above post says....

    There are more greases to use than silicone grease. Thomas and Betts makes Contax, which is what we used on a plating line. There is conductive pastes also from T&B. Copper is usually the conductive medium. Mcmaster sells the stuff. Electrical supply store (wholesale) should have the stuff too.
    #10
  11. WB-PDX

    WB-PDX Long timer

    Joined:
    May 11, 2008
    Oddometer:
    3,810
    Location:
    Where young people go to retire
    I use the toothpaste-style dielectric frequently, because it aids in getting stuck\finnicky connectors apart, especially like the 6+ pin ones found on bike wiring harnesses, and the spring-style spark plug boots. Anyone with a bike older than about 1990 can attest to how well-stuck those damn molex style connectors become. It's also good for things like door switch plugs on cars, where there's no sealing of the switch-connectors, but moisture can (and will) get in.

    Electrical parts cleaner (or simple, newer, less-flamable WD40 in a pinch) is probably what most people want to use when they go nuts with grease.

    Interesting stuff about the out gassing.
    #11
    zivi123 likes this.
  12. SnowMule

    SnowMule still learning what is and isn't edible Super Supporter

    Joined:
    Jul 2, 2009
    Oddometer:
    23,667
    Location:
    I LIVE IN A GIANT BUCKET
    I packed all the connectors full of silicone vacuum grease.... no problems since.
    #12
  13. Twinz

    Twinz Been here awhile

    Joined:
    Sep 16, 2005
    Oddometer:
    542
    Location:
    VT
    #13
  14. johnjen

    johnjen Now, even more NOW!…

    Joined:
    Nov 28, 2001
    Oddometer:
    17,035
    A little known secret that Stabilant 22A
    And if you REALLY want to tweak your EFI use it on EVERY sensor and injector. And then when you notice the improvement and if you're really motivated, go for the main connector that plugs into the 'brain'.

    And there is stuff even better that red DeOxit. I like Caigs ProGold for gold contacts. Although DeOxit does a pretty good job of breaking up the corrosion on contacts that are heavily pitted and oxidized.

    http://www.stabilant.com/
    http://store.caig.com/

    And if you are really into this stuff there is silver powder mixed in with a carrier that is also quite effective. It comes from the audiophile world.

    JJ
    #14
  15. Streamin' E

    Streamin' E Half-assed adventurer

    Joined:
    Oct 24, 2002
    Oddometer:
    1,448
    Location:
    Carefree Highway
    Thanks Gents. I've ordered some Deoxit and Stabilant.
    #15
  16. Jack90210

    Jack90210 quia ego nominor leo

    Joined:
    Oct 11, 2004
    Oddometer:
    16,544
    Location:
    :jack
    Good tip on the Stabilant 22A, thanks. I'll try that when my bottle of ProGold runs out, which will probably be around 2035. :lol3

    I'm currently going through the wiring of my R1100GS: redoing PO's mistakes, adding relays for lights, looking for rubbed wires and using the ProGold (since renamed as DeoxIT Gold) on every connector. Gonna have to try it on the Motronic brain -- thanks for the tip, I think.
    #16
  17. H96669

    H96669 A proud pragmatist.

    Joined:
    Nov 20, 2009
    Oddometer:
    5,989
    Location:
    Hiding off Hwy 6, B.C.
    I use this....no sillycones. :D

    http://www.jamestowndistributors.com/userportal/show_product.do?pid=9467

    In the little pump bottle not the aerosol.Seeps right into them really small BMW pin connectors. Just redid the ABS ones yesterday, still all looked like new from the last application 2-3 years ago. And so do the ones I found greening years ago from exposure to the nasty chlorides.:eek1

    Good enough for boats...more than good enough for me. But there is a motorcycle on the can also.:wink:
    #17
  18. johnjen

    johnjen Now, even more NOW!…

    Joined:
    Nov 28, 2001
    Oddometer:
    17,035
    Just an added bit of info about Stabilant 22a and Dexoit-Gold.

    Stabilant 22a is a contact enhancer and sealant. It actually creates a larger contact patch. Or put another way it lowers the contact resistance AND seals the 'edges' of the contacts themselves so that moisture and other contaminants stay out of the active signal transfer area.

    Stabilant is really effective for connections that are exposed to water or other sources of corrosion at the contacts themselves.

    Deoxit is a cleaner / enhancer / lubricant to minimize surface oxidation and allow less wear during sliding in and out.

    Deoxit is a general purpose contact enhancement chemical that works especially well on gold and silver etc.

    And yeah with Deoxit, since you use so little, your supply last a really long time. I've had my spray can and container with pads since the 80's and I have well over half of both of them, still.

    I first heard about Stabilant being used in the automotive industry when Infinity had HUGE problems with water collecting in connectors at the low spots of the wiring harnesses. It was 'solved' by using Stabilant to seal up the connections among other remedial changes.

    JJ
    #18