EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: PlainName on November 05, 2024, 03:55:04 pm
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Stihl recommend that connectors in their mower should have grease applied before assembly. I presume it's to stop corrosion (these are typically power connectors). The grease is quite thin to the touch, almost like oil.
Anyone know the spec and where to get some?
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Get the stuff in my link: https://www.eevblog.com/forum/repair/axle-grease-for-fan-in-hp-pavilion-laptop/msg5458250/#msg5458250 (https://www.eevblog.com/forum/repair/axle-grease-for-fan-in-hp-pavilion-laptop/msg5458250/#msg5458250)
It has the consistency of mayonnaise. Great for axle and ball bearings.
Though, I think for electrical contacts, you might need something specialized, maybe even thicker. For electrical contacts, you may need something as thick as Vaseline.
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Stihl sells a variety of greases. Is there one specifically it recommends? 00 "Grease" is like a heavy oil. It's quite cheap: https://www.agrisupply.com/superscotton-picker-00-grease-qt/p/134219/?gad_source=1&gclid=EAIaIQobChMItK3JgdDFiQMVoXRHAR3SzSE7EAQYASABEgJYevD_BwE (https://www.agrisupply.com/superscotton-picker-00-grease-qt/p/134219/?gad_source=1&gclid=EAIaIQobChMItK3JgdDFiQMVoXRHAR3SzSE7EAQYASABEgJYevD_BwE) It presumably sticks to stuff like open gears in cotton pickers. Another sticky oil is bar and chain oil or Lubriplate 105 "motor assembly oil.".
If the purpose is anticorrosion, I might use LPS 3. A very cheap alternative is 20 or 30 weight non-detergent oil that I keep in squirt cans. Aside from the distinction "Stihl," I suspect there's not a lot of difference.
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I don't know Stihl's spec, but Nye claims most automakers use their Nyogel 760G in connectors. However, it's not thin like oil and it's clear. They have a lot of documentation to push their view, but you could probably use any "dielectric" grease from an auto parts store. I would not use an ordinary lubricating grease. It might work, but could be messy after a few years.
https://www.nyelubricants.com/connectors (https://www.nyelubricants.com/connectors)
Have you asked Stihl? A shame they recommend grease but don't say what to use.
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Thanks both. Stihl parts diagram says "Fill the socket with special grease (DC4) before connecting the cable". So.. DC4, whatever that is, and a search pops up:
https://www.mowersplus.co.uk/STIHL-886661115303-Special-grease-DC4-Part-0781-110-1011 (https://www.mowersplus.co.uk/STIHL-886661115303-Special-grease-DC4-Part-0781-110-1011)
Looks to be a bit expensive and usually on back order, and I suspect it is some common stuff branded by Stihl (rather than some custom recipe). The reason I think it is a bit thin is because I got it on my fingers when dismantling a robomower. I could be mistaken about viscosity though.
Sorry for the lack of info in the original post. Fingers getting ahead of brain...
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You can get Nyogel from Ford motors much cheaper:
https://www.amazon.com/Genuine-Ford-XG-12-Electrical-Grease/dp/B000NUBB28/?th=1 (https://www.amazon.com/Genuine-Ford-XG-12-Electrical-Grease/dp/B000NUBB28/?th=1)
and Permatex is likely very similar if not the same:
https://www.amazon.com/dp/B000AL8VD2/ (https://www.amazon.com/dp/B000AL8VD2/)
And you can likely get one or the other locally.
These are specifically recommended for electrical connectors. I have a tube of Nyogel, but it was expensive, hard to find in consumer quantities, and it was before I discovered the Ford rebrand.
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A little googling and checking product images leads to Dow Corning DC4 Electrical Insulating Compound, which is a silicone based dielectric grease. Dow bought out Corning and merged with DuPont, so DC4 is now sold under DuPont's Molykote brand name as Molykote 4 (https://www.dupont.com/products/molykote-4-electrical-insulating-compound.html).
You can substitute other Silicone dielectric greases of similar consistency, but switching to a non-silicone dielectric grease would involve cleaning off all the old grease (and silicone grease is a PITA to totally remove) and checking compatibility of the new grease with the plastics used in the insulation.
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Interesting. Nyogel is not silicone, but a PAO synthetic oil base IIRC. The major difference is that DC4 has a warning not to use with silicone rubber like O-rings, as they state it will destroy them (Dupont technical data sheet).
edit: the TDS on the Dupont site is missing some text found on older TDS. I looked at a 2019 edition of the TDS.
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Your Permatex suggestion looks like its suitable:
https://www.permatex.com/wp-content/uploads/tds/22058.pdf (https://www.permatex.com/wp-content/uploads/tds/22058.pdf)
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No-ox-id brand of electrical contact grease has been used by telcos on major 48V copper bus distribution systems for decades. It just works, it is light brown similar to many petroleum based greases.
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You can get Nyogel from Ford motors much cheaper:
https://www.amazon.com/Genuine-Ford-XG-12-Electrical-Grease/dp/B000NUBB28/?th=1 (https://www.amazon.com/Genuine-Ford-XG-12-Electrical-Grease/dp/B000NUBB28/?th=1)
and Permatex is likely very similar if not the same:
https://www.amazon.com/dp/B000AL8VD2/ (https://www.amazon.com/dp/B000AL8VD2/)
And you can likely get one or the other locally.
Brilliant, thanks. The ford one is stupidly cheap here on Amazon UK, whilst the Permatex is, er, not cheap.
Edit: different Ford stuff. And small. Gone for the Permatex :)
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now sold under DuPont's Molykote brand name as Molykote 4.
Aka Hen's Teeth here :)
Hard to keep track of what brand is where sometimes!
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1) I would not use anything with molybdenum (Molykote implies) where corrosion around water was a concern. In brief, I don't use it with farm implements for anything. It promotes corrosion on steel. I use Lucas Red 'n Tacky #2, because I like the color. Any #2 would suffice. But the lucas is tacky.
2) If you demand dielectric, use any dielectric grease. But that is not a spark plug, it is low voltage. Hence, any grease will work. Earlier, I blanked on the name of what I switched to from LPS 3, it's Kel rust inhibitor (https://www.plumbersstock.com/3rd_10912339_penetratingoilrustinhibitor.html?utm_source=google&utm_medium=cpc&adpos=&scid=scplp598764&sc_intid=598764&gad_source=1&gclid=EAIaIQobChMIg63em_LFiQMVpUb_AR2DdwYGEAQYASABEgIniPD_BwE (https://www.plumbersstock.com/3rd_10912339_penetratingoilrustinhibitor.html?utm_source=google&utm_medium=cpc&adpos=&scid=scplp598764&sc_intid=598764&gad_source=1&gclid=EAIaIQobChMIg63em_LFiQMVpUb_AR2DdwYGEAQYASABEgIniPD_BwE) ).
3) Real farmers (I am just a hobby farmer) rely on their mechanics. I have been told that the only time brand may make a difference is with hydraulic transmissions. I follow that advice with my cars and other hydraulic drive implements. Considering the downside, the cost difference becomes insignificant. A Stihl lawn mower electrical plug is not in that class.
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1) I would not use anything with molybdenum (Molykote implies) where corrosion around water was a concern.
Molykote is now the umbrella brand name for the entire DuPont and ex-Dow Corning lubricant lines. It doesn’t tell you anything whatsoever about its composition.
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It appears Permatex is likely a direct substitute for DC4, both being silicone. Just don't get it near silicone rubber items.
If you do need to lubricate silicone items like O-rings or gaskets, I'd use Nyogel. Anecdotally, it's fine on silicone rubber as well as typical buna o-rings.
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1) I would not use anything with molybdenum (Molykote implies) where corrosion around water was a concern.
Molykote is now the umbrella brand name for the entire DuPont and ex-Dow Corning lubricant lines. It doesn’t tell you anything whatsoever about its composition.
Thanks, I didn't waste time checking. I guess Molykote is like Gillette Hybrid razor blades (still in development). :)
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NO-OX-ID is something I have not used. Apparently it's been around for decades in industrial use. I asked some electronics friends about it last year and no one had used it.
https://www.sanchem.com/electrical-contact-lubricant.html (https://www.sanchem.com/electrical-contact-lubricant.html)
https://www.amazon.com/NO-OX-ID-Special-Electrical-Contact-Corrosion/dp/B00HDF9EXE/ (https://www.amazon.com/NO-OX-ID-Special-Electrical-Contact-Corrosion/dp/B00HDF9EXE/)
I am sure there are other industrial suppliers of suitable grease, like Caig (Deoxit) and Krytox, but you might have to buy 5 gallons of it.
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Good to see Farnell still listing the original name of the product (MS4) in the description;
https://uk.farnell.com/dowsil-formerly-dow-corning/dc4/compound-silicone-dc4-tube-100g/dp/537019?srsltid=AfmBOopnuDAGzm_YOxZfO7xqR8fI9EYiJBCtkegOup7_CSuqQABHbayo
Over here it was originally from Midland Silicones, Dow Corning took them over, but kept it as MS4, then eventually renamed it DC4.
David
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As a man with great wisdom once said,
Grease is the word, is the word that you heard
It's got a groove, it's got a meaning
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And what can you say about such protective lubricants? Price-quality ratio?
CONTRALUBE 770
LIQUI MOLY Batteriepolfett
Technical Petroleum Jelly (Vaseline)
Waxoyl HC Plus
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I just use silicone grease for electrical connections resists water and prevents corrosion and does not affect plastics in the way some mineral grease can.
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I just use silicone grease for electrical connections resists water and prevents corrosion and does not affect plastics in the way some mineral grease can.
I read somewhere that one mustn’t use silicone on contacts that can arc (like in switches and connectors that are mated/unmated under load), because arcing causes it to decompose to abrasive silicon carbide, causing subsequent contact damage.
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Re: Plastic compatibility
Most common plastics used for electronics are stable to mineral oil greases: https://support.newgatesimms.com/lubricants-and-possible-plastic-or-rubber-compatibility-issues/
If you are worried about compatibility, you can use a perfluoropolyether (PFPE) based lubricant. But, beware of sticker shock. PFPE and PFAE(perfluoroalkylether) and probably some other names are very similar if not the same.
When model airplane servos usually had plastic gears, I used Krytox (a PFPE lubricant) from McMaster-Carr. My 2 oz tube coat $16. That price on Amazon today is $26. That's almost three times what I pay for good, dried real Italian porcini mushrooms. :)
Edit: corrected spelling of Krytox
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I'll try the mushrooms and report back.
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Another thing you could try is string wax/lube for crossbows, which despite its name is a PTFE and/or silicone lubricant. It's usually sold in a chapstick-style tube that makes it easy to apply.
As with anything like this, there's a million opinions on which one is the most cromulent on crossbow forums.
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Where would that be used on a crossbow?
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Modern crossbows are complex:
[plain]https://www.youtube.com/watch?v=0WfSXzQohlE [/plain]
I let a friend hunt deer on woods around my home. There are several different seasons for different ages of hunter and weapons. I was amazed at the modern crossbow's accuracy and power. I suspect he has harvested more deer with that than with a rifle or musket. BTW, he hunts mainly for food. Any trophies are largely incidental with years in between. I have known him to track a particular buck for 3 years or more before getting it.
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I read somewhere that one mustn’t use silicone on contacts that can arc (like in switches and connectors that are mated/unmated under load), because arcing causes it to decompose to abrasive silicon carbide, causing subsequent contact damage.
No you don't want silicone anywhere near arcing contacts. I think it's tough and insulating silicate layers that form but I wouldn't be surprised if there was some carbide formation in things like motor brush gear.
I remember allowing the neighbor's kids to 'valet' the inside of one of my cars many years back. It took me ages to get the indicator and wiper switch stalks etc. working reliably again!
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Where would that be used on a crossbow?
On the rails that the bolt runs on, and on the strings, which are typically made up of multiple synthetic fibres like dacron and for which the "wax" reduces wear and tear.
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Learn something new every day :-+