Replacing some gauges on my engine panel. Is dilectic silicone grease the right product to use on the nuts/connections. Can I just slather it on the connections after I get them together. I'm talking about the spade connectors and screwed connections. All the butt connections are getting heat shrinked.
On a similar note, what is the best product to used on stainless nuts and bolts up on deck to prevent any corrosion on the threads. Would the dilectric grease work on those also?
mre : I've used that dielectric silicone with success on electrical connections, but it needs to go on the threads, and not just slithered on!!
Water resistant grease is what I use on anything to coat 2 different metals from corroding. Lanacoat(sp?) is also good stuff to prevent corrosion.
A thought
Thanks Ron.
Look up the term dielectric in the dictionary. It's and insulator will not conduct electricity. What you want is A conducting grease for dissimilar metals, any electrical supply hs or home depot will have it they use it to connect aluminum an copper wire together. Charlie
PS must wipe off all excess because it will conduct Charlie
Au contraire re: 'conducting" grease. Yes, what you want is dielectric grease --
SuperLube PTFE gel is excellent for the purpose, as well as lubing most any other threaded connection. NO BOAT should be without at least one tube of it. The SuperLube dry PTFE spray is an excellent lube also (it's like SailKote).
You apply it very sparingly on the connection/terminal and then tighten up -- the pressure essentially cuts thru and displaces any dielectric where there's direct contact, leaving protection where there's any tiny space -- thus preventing corrosion there.) To protect the outside of the threads/nuts you can use a brush-on terminal protector (like NCP-2, battery terminal protector) or a brush-on liquid tape to form a complete seal. But it sounds like possibly unnecessary overkill -- if you use brush-on tape on the outside, using grease on the terminal is probably unnecessary, but won't hurt anything and is simply belt/suspenders.)
kk
I have SuperLube and Tef-Gel for preventing corrosion between dissimilar metals (SS screws in aluminum mast, etc.). But neither of these were designed for electrical applications AFAIK.
The December 2010 issue of Practical Sailor shows pretty clearly that NO-OX-ID is probably the most effective for electrical connections. (Although they don't say, it is clear from the description that they used the "A Special" formulation which is conductive.) I have ordered some for some rewiring that I need to do, but haven't received it yet. Since it is conductive, so should only be used in contact areas like battery terminals, ring connectors, and inside butt connectors. It should not be used on multi-pin connectors where it could cause short circuiting. For those sorts of things, a dielectric grease is best.
Also steer clear using any dielectric grease on antenna connections, since dielectric properties can change at high frequencies.
SuperLube markets a dielectric. They confirmed to me that it's the same product as the PTFE gel. Truth in advertising. Not.
Below is a quick primer and some tips on contact protection: *
- There is no need to use truly conductive grease for electrical contact lubrication/protection; the contact pressure cuts through the grease down to the sub-micron level and electrons then "tunnel" through.
- The primary purpose of the grease is to form an airtight coating around the contact area to prevent oxidation (especially a phenomenon known as "fretting corrosion".
- Products intended specifically as contact lubes usually include solvents specifically chosen to clean and absorb/remove moisture.
- Some greases sold for contact protection label themselves as "conductive" when in fact they are really just referring to the fact that they don't interfere with the electrical connection due to the contact pressure cutting through the grease sufficiently to allow electrical flow. Truly conductive greases (e.g. carbon or silver loaded) are used for very specialized applications and have drawbacks for typical electrical contact uses.
- You do not need to use a product labelled "dielectric" either. That designation is only important for very high voltages such as around spark plug boots. That said, most dielectric greases are fine to use as a contact lube-protectant, though they are not as good at cleaning and absorbing trace moisture as are the specially designed contact lubes.
There are a few caveats:
1) Don't use greases that are so viscous that the electrical contact cannot cut through it. Most light-weight greases are probably fine, including vaseline in a pinch.
2) If putting on the base of incandescent bulbs make sure it can take the heat. (Vaseline will give off a burning odor)
3) Some contact lubes include chemical agents to actively remove existing corrosion (e.g. DeoxIT D-series). Be cautious, although those chemicals are useful, they could potentially cause more corrosion later. Better to clean first if possible, then use a more inert version (e.g. AX-7 or DeoxIT Gold).
4) Best to avoid silicones, as the invisible film creeps extraordinary distances (inches) over time, and even microscopic amounts can interfere with bonding of future application of glues, paints, varnishes, etc. Also never use silicone on switch or relay contacts, as the normal arcing of contacts opening can convert the silicone to silicon carbide, a very hard insulator.
5) It's better to avoid using PTFE-loaded grease as a contact lube, as the PTFE particles can flatten out and end up blocking some of the tiny microscopic contact areas, resulting in a less effective contact area. This has been borne out in manufacturer tests, though it is not such a big deal as to have one worry if they have been using such products. Going forward, though, it's best to use products without any PTFE.
6) There are also products sold for use inside of aluminum wiring splices. Some of those (e.g. Noalox) include grit designed to dislodge any oxide on the wire during the tightening of the splice connector. Needless to say, don't use such grease as a contact lube.
7) The lower the contact pressure, the more important the characteristics of the lube. If you are simply protecting a ring terminal under a tightened nut from corrosion, anything is fine. If it's a low-pressure delicate electronics connector contact, then a speciality product is best.
* I am an electrical engineer with special experience in electronic contact lubrication dating back over 20 years.
J_
Thank you for the grease primer - very informative!
Interesting about your ptfe note - I looked back and (mea culpa) superlube hadn't said its hi dielectric gel and lube gel were identical, they said either could be used. I checked just now and its DEG doesn't contain ptfe.
Ken,
Thank you for your inquiry and interest in Super Lube®. The difference in the two products is p/n 92003 contains PTFE which is a Teflon equivalent. You can use either product for your electrical applications, no need to carry two different products.
Regards
So with the 1st below being it's hi-DE product, is the silicone a concern for our usual marine uses? (I don't see us needing to paint a terminal block or an oil switch :wink: )
Would you say the 2nd below p/n 82003, connector gel, is a better choice? What I get out of the primer is that for our low-tech application any of the three superlube gels would do just fine?
kk
FWIW, my SuperLube is a totally different product, their "Synthetic Grease" meant for lubricating. It also has PTFE. I bought it to lubricate the steering chain on my C250, and then inherited a second tube that the PO of my current boat left behind.
To add to the knowledge base here, I exchanged a private message today with Drew Fry, who did the 2010 corrosion testing for Practical Sailor:
QuoteHi Drew,
I need to replace my float switch. It's going to require splicing with a heat-sealed butt connector in the bilge, and I want to make sure I minimize any possible corrosion. I've ordered some NO-OX-ID for general use around the boat, and am also considering some lower viscosity penetrating spray for other hard-to-reach places (unrelated to the splices).
I know that you were heavily involved in the Practical Sailor testing of anti-corrosives in 2010, so would value your recommendations, In particular, I am curious about why the TC-11 that was so highly rated in 2007 was not included in your testing in 2010. Has there been a formulation change or something else affecting efficacy or availability?
What products do you currently use for various anti-corrosion needs?
Thanks,
Rick Sonntag
Swarthmore, PA
s/v "Breakin' Away" in Rock Hall MD
---End Quote---
No particular reason, TC-11 simply was not included. I have no reason to think it isn't very good. As for spray, I've been using Corrosion Block. They also make a grease which is pretty good, though not as good as...
Green Grease. Actually, there is a new set of grease tests coming out soon in PS, and Green Grease (omni lubes--they have it at Advanced Autoparts) seems even better, although No-Ox-Id is still very good. Thee will also be an article coming out showing that conductive greases that contain metals actually increase corrosion, compared with plain grease. Dissimilar metals, it seems, never help.
So long as you use a properly adjusted ratchet crimper (test pulling the wire out, hard--something should break) grease is not needed.
Subscribe!!
There are multiple applications being discussed here. Let's separate them:
1) Protecting low-pressure electrical contacts (especially that might be disassembled and reassembled later), including:
Multi-pin connectors (both larger styles used in wiring harnesses and tiny ones inside of electronic devices)
Circuit board edge connectors (incl SIM card contacts)
Faston/spade connectors (between the male and female connectors, not the crimp to the wire, which needs no lube)
Light bulb sockets
2) Protecting larger high pressure contacts (e.g. ring terminal on a stud) up to and including battery connections
3) Sealing complete electrical/mechanical assemblies against corrosion (like spraying TC-11, Boeshield T-9, or Corrosion Block on the back of an instrument panel).
For the first category I prefer to use specialty contact lube-protectants that are dissolved in a solvent carrier rather than a grease, particularly for small electronics connector contacts. They are applied with a tiny brush (like in a nail-polish bottle) or from a spray can with the tiny straw attached. You use very very little. The speciality products serve to seal around the contact surface, as well as lubricate the contacts during insertion/withdrawal and during vibration (to prevent fretting corrosion). The solvent helps clean the contact and spread the lube into a very thin layer. Examples are DeoxIT Gold and AX7-C (my favorite, based on a military avionics contact lube but no longer available to consumers due to solvent regulation issues). For larger contacts in wiring harnesses a light grease is fine, but avoid ones with PTFE (i.e no SuperLube Synthetic w Syncolon). I also try to avoid silicone when I can for other reasons (yes, I'm a bit of a fanatic), but that eliminates SuperLube's synthetic or dielectric, as one contains PTFE, the other silicone. SuperLube makes great greases, they're just not ideal for tiny electrical contacts. Their Contact Gel, though, looks like it would work well, but maybe not as easy to apply to small contacts as a liquid would be.
For the second category, contact lubes are not technically necessary, as corrosion won't readily penetrate into the high-pressure contact area. That said, it's still a good idea to coat the area with a light grease either before or after assembly. Before is best, but afterwards is better than nothing. Almost any grease will do in this application, even ones with PTFE.
For the third category, you are not really applying a contact protectant, you are conformally coating the entire assembly. In that case the primary concern, beyond the degree of protection, is that the coating not damage anything (plastic compatibility) and not create a mess. I have read many reviews of such products and the degree of protection mostly correlates to the viscosity of the coating.
Useful Links:
DeoxIT Gold - https://www.amazon.com/dp/B000RGD9QE
Articles in case you are not already exhausted.
http://support.newgatesimms.com/wp-content/uploads/Electrical_Connector_Grease_Facts_And_Myths.pdf
http://www.rc-electronics-usa.com/connector-lubricant-detail.html
http://www.electrolube.com/pdf/contact-lubricants-brochure-electrolube.pdf
Bottom of page four of article below discusses the problem of PTFE in contact lube :
http://www.w8ji.com/images/Cars/Battery/NEW_8917_Marketing_WP.pdf
Someone asked why no silicone. Someday you will try to epoxy something nearby, or need to caulk around an assembly and wonder why you have adhesion problems. Invisible films of silicone oil tend to get on everything, including stray rags, and trip you up later. Ask anyone who does hi-tech bonding or spray painting. If you ban it from your toolkit you have eliminated a potential problem later.
Quote from: J_Sail on December 30, 2016, 10:27:25 PM
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2) Protecting larger high pressure contacts (e.g. ring terminal on a stud) up to and including battery connections.
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For the second category, contact lubes are not technically necessary, as corrosion won't readily penetrate into the high-pressure contact area. That said, it's still a good idea to coat the area with a light grease either before or after assembly. Before is best, but afterwards is better than nothing. Almost any grease will do in this application, even ones with PTFE.
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Someone asked why no silicone. Someday you will try to epoxy something nearby, or need to caulk around an assembly and wonder why you have adhesion problems. Invisible films of silicone oil tend to get on everything, including stray rags, and trip you up later. Ask anyone who does hi-tech bonding or spray painting. If you ban it from your toolkit you have eliminated a potential problem later.
For the second category, I agree. Would it be helpful to add the use of heat shrink or Liquid 'Lectric Tape to those suggestions?
I also agree about silicone. Since the "invention" of Maine Sail's butyl tape, I, too, have banned silicone from my boat EXCEPT for the Beckson portlights. Those ports are the ONLY place that I use silicone on my boat. The older boats have eight of them, the later Mark 1 to Mark 1 1/2 boats with Lewmar ports still have two in the cockpit. The Mark II boats have no Beckson ports.
Engineers: Can't live with'em, can't live without'em... :shock: :abd: 8)
Quote from: Noah on December 31, 2016, 08:26:33 AM
Engineers: Can't live with'em, can't live without'em... :shock: :abd: 8)
Sounds exactly like what my wife just said. :shock: :cry4` :clap :D
Stu,
I don't understand what you're suggesting re: #2?
Heat shrinking over a battery terminal stud/nut (wouldn't that be impossible due to the large cable lug?) or over a stud on a terminal strip or alternator stud (nearly impossible due to the ring terminal itself)?
Slather an alt stud or battery terminals with liquid tape? Maybe, but I wouldn't. I previously mentioned LT but in reference to a light coating on a "permanent" out of sight/mind connection (gauge, switch terminals) behind the engine panel. I think one exception where heat shrink could be used is to encase "in line" quick disconnects. Or as I think we discussed on the phone that night (my time,) encasing the quick disconnect on the starter solenoid "S" wire/terminal (after removing the fuse, of course. :wink: ) if you don't have a threaded-stud type solenoid.
FWIW, I'll add CRC 06026 Heavy Duty Corrosion Inhibitor to the list of total assembly protectants (like TC-11.) It may not be as high-tech/mil spec as others, but for our use, more economical. I'll submit that these be used can be used on individual assemblies (#2, like terminal block studs, alt studs, engine senders, etc.) as well.
I've ordered the SuperLube 82003 connector protectant to give it a try and check the viscosity (could it be brushed on before assembly, rather than the super expensive alternatives?)
-ken
Quote from: Noah on December 31, 2016, 08:26:33 AM
Engineers: Can't live with'em, can't live without'em... :shock: :abd: 8)
Noah, There's left-cost and right-coast engineers!!! :rolling :wink: :roll: :shock:
kk
Quote from: KWKloeber on December 31, 2016, 12:17:47 PM
Stu,
I don't understand what you're suggesting re: #2?
Heat shrinking over a battery terminal stud/nut (wouldn't that be impossible due to the large cable lug?) or over a stud on a terminal strip or alternator stud (nearly impossible due to the ring terminal itself)?
Nope, c'mon. Part of #2 is wires into connectors, like butt connectors or even wires into battery lugs. That's all.
Quote from: Stu Jackson on December 31, 2016, 12:26:52 PM
Quote from: KWKloeber on December 31, 2016, 12:17:47 PM
Stu,
I don't understand what you're suggesting re: #2?
Heat shrinking over a battery terminal stud/nut (wouldn't that be impossible due to the large cable lug?) or over a stud on a terminal strip or alternator stud (nearly impossible due to the ring terminal itself)?
Nope, c'mon. Part of #2 is wires into connectors, like butt connectors or even wires into battery lugs. That's all.
Stu
I see the confusion!
His discussion of 1,2,3 was specifically (only) the physical terminal, post, or pin connections -- not the wire or cable crimp itself. Previous clarified that it didn't apply to the crimp, which shouldn't have any dielectric or other goop applied before crimping w/ adhesive heat shrink terminals. :thumb:
There isn't any particular harm in putting a thin layer of contact lube or grease on a wire prior to crimping, but it is not necessary. The idea of crimping is that the pressure forms what's called a "gas-tight" seal in the contact area, which protects it from corrosion where it matters. Corrosion outside of that area, while unsightly, doesn't interfere with the connection.
By the way, NO-OX-ID is not actually conductive; it's one of those products where the company decided to (mis)describe it as conductive to better appeal to consumers, who would otherwise worry about putting non-conductive grease on electric contacts. It is no more or less conductive than typical dielectric greases. It's all about the fact that in the actual contact area, the microscopic peaks of the contact press through the grease to allow electricity to flow.
Dialectric greese is definitely what to use. I have sold the product into the trucking market for years, mechanics use it on all connections. It is water proof and does let the current thru. Several brands are in the market, and can be purchased at local auto and truck parts stores. Look for brand by CRC, Trucklite, Grote, I've sold CRC for years. Can be bought in cheese whiz style cans with nozzle of just canned, applied with small brush. Just make sure can states dialectric greese.
J_
I got a reply from SuperLube re the difference between their dielectric grease and gel contact corrosion preventer. to wit:
Ken,
Our part number 91003 is our super Lube® Silicone Dielectric Grease and part number 82003 is our Anti-Corrosion Gel. I have listed some differences.
The grease is much thicker than the gel.
The grease uses silicone oil as its base oil, whereas the gel uses a blend of mineral oil and PAO oil.
There is a higher concentration of anti-corrosion additives in the gel.
The gel has been tested and approved by Thermo-King for their electrical connectors on refrigerated trailers to reduce road salt corrosion and fretting. (see attached link)
http://www.super-lube.com/files/pdfs/Connector_Gel.pdf
I have attached a few links for your review.
http://www.super-lube.com/files/pdfs/silicone_dielectric_grease_technical_bulletin.pdf
http://www.super-lube.com/files/pdfs/Technical_Bulletin_Anti-Corrosion_&_Connector_Gel.pdfFWIW I got in my tube of (ptfe-free) connector gel and it's pretty similar to the SL ptfe lube. It could probably be brushed on with, say, a flux brush, especially if warmed a titch.
I had said "
....the crimp, which shouldn't have any dielectric or other goop applied (my interjection, not your words)
before crimping w/ adhesive heat shrink terminals," because -- it's just the *best choice* for the average DIYer to avoid it -- not unlike soldering and as you say silicone in the toolbox. Getting any dielectric on the insulation, either through handling or squishing out while crimping, will prevent adhesion of the AHS on the terminal/butt connector.
-ken
Quote from: J_Sail on January 03, 2017, 09:43:32 PM
There isn't any particular harm in putting a thin layer of contact lube or grease on a wire prior to crimping, but it is not necessary. The idea of crimping is that the pressure forms what's called a "gas-tight" seal in the contact area, which protects it from corrosion where it matters. Corrosion outside of that area, while unsightly, doesn't interfere with the connection.
By the way, NO-OX-ID is not actually conductive; it's one of those products where the company decided to (mis)describe it as conductive to better appeal to consumers, who would otherwise worry about putting non-conductive grease on electric contacts. It is no more or less conductive than typical dialectic greases. It's all about the fact that in the actual contact area, the microscopic peaks of the contact press through the grease to allow electricity to flow.