Silicone Grease [message #188445] |
Sat, 27 October 2012 15:47 |
Who_dun_it
Messages: 176 Registered: April 2007 Location: Thousand Oaks, CA
Karma: 1
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Hi - where are you folks finding silicone grease? I have been to NAPA a couple times and what they come up with is small tubes of dielectric grease.
Les
T.O. CA
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Re: Silicone Grease [message #188458 is a reply to message #188445] |
Sat, 27 October 2012 18:25 |
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Matt Colie
Messages: 8547 Registered: March 2007 Location: S.E. Michigan
Karma: 7
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Who_dun_it wrote on Sat, 27 October 2012 16:47 | Hi - where are you folks finding silicone grease? I have been to NAPA a couple times and what they come up with is small tubes of dielectric grease.
Les
T.O. CA
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Les,
Silicon grease is dielectric grease.
If you want a bigger tube, look up silicon mold release agents. The one that we have been using for ever is Dow Corning 7. It isn't cheap, but you don't use a whole lot. If I had to go and buy it, I would go looking for pattern shop suppliers and fiberglass molding stuff suppliers. You can get it from Amazon, but I'll bet you can beat their price.
My father passed 30+ years ago. When he did I got his DC7 to add to my collection one half gone tube, one three quarter gone and one new in the box. There were all 8oz tubes. I opened the box just this year. It still have most of the half gone tube.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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Re: Silicone Grease [message #188473 is a reply to message #188445] |
Sat, 27 October 2012 20:37 |
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JShot
Messages: 485 Registered: October 2006 Location: NW Ohio
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Who_dun_it wrote on Sat, 27 October 2012 16:47 | Hi - where are you folks finding silicone grease? I have been to NAPA a couple times and what they come up with is small tubes of dielectric grease.
Les
T.O. CA
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Les,
Google "Sil Glide" - I got mine at NAPA
John
John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
[Updated on: Sat, 27 October 2012 21:21] Report message to a moderator
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Re: [GMCnet] Silicone Grease [message #188483 is a reply to message #188462] |
Sat, 27 October 2012 22:14 |
Carl S.
Messages: 4186 Registered: January 2009 Location: Tucson, AZ.
Karma: 13
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Les,
When I installed my reaction arm kit, I used some silicone grease that I had left over from putting urethane bushings in the front control arms. It was really sticky stuff than came in a small (1 oz.??) container. Jim K. might have some.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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Re: Silicone Grease [message #188521 is a reply to message #188445] |
Sun, 28 October 2012 10:59 |
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Matt Colie wrote "Silicon grease is dielectric grease".
One word of caution and to, hopefully, eliminate some confusion - there is heat transfer silicone product that has the consistency of grease and we use it to between the center of the ignition module and the distributor on our HEI systems. I bought a small tube of this heat transfer silicone at my local Radio Shack. It is is NOT dielectric grease.
At the Amanna rally Dick Paterson recommended that we use the dielectric grease where the 2 screws attach the ignition module to help the ground connection.
Bill Brown - '77 Buckeye Cruiser
Coshocton OH
carguybill@sbcglobal.net
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Re: [GMCnet] Silicone Grease [message #188525 is a reply to message #188503] |
Sun, 28 October 2012 11:40 |
Who_dun_it
Messages: 176 Registered: April 2007 Location: Thousand Oaks, CA
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Thank you all for the input. I will look for plumbers silicone first.
Now, when I am away from home, I can call myself a silicone grease expert.
Les
Steven Ferguson wrote on Sun, 28 October 2012 06:18 | Les,
If it is for bushings etc, just go to ACE and buy a small container of
plumbers silicone. Works excellent and is very inexpensive.
On Sat, Oct 27, 2012 at 1:47 PM, Les Leach <les.leach@yahoo.com> wrote:
>
>
> Hi - where are you folks finding silicone grease? I have been to NAPA a
> couple times and what they come up with is small tubes of dielectric grease.
>
> Les
> T.O. CA
> _______________________________________________
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Fathom the hypocrisy of a nation where every citizen must prove they have
health insurance......but not everyone has to prove they're a citizen.
Steve Ferguson
Sierra Vista, AZ
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Re: Silicone Grease [message #188578 is a reply to message #188521] |
Sun, 28 October 2012 19:32 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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carguy wrote on Sun, 28 October 2012 10:59 | Matt Colie wrote "Silicon grease is dielectric grease".
One word of caution and to, hopefully, eliminate some confusion - there is heat transfer silicone product that has the consistency of grease and we use it to between the center of the ignition module and the distributor on our HEI systems. I bought a small tube of this heat transfer silicone at my local Radio Shack. It is is NOT dielectric grease.
At the Amanna rally Dick Paterson recommended that we use the dielectric grease where the 2 screws attach the ignition module to help the ground connection.
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Dielectric grease in non-electrically conductive.
http://en.wikipedia.org/wiki/Dielectric
For this reason I can not understand why one would want it on the mounting screws grounding something. Basically dielectric grease is an insulator. This is why we use it on things like spark plug boots. Lubrication and sealing without electrical conduction.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Silicone Grease [message #188601 is a reply to message #188578] |
Sun, 28 October 2012 23:34 |
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Matt Colie
Messages: 8547 Registered: March 2007 Location: S.E. Michigan
Karma: 7
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Ken Burton wrote on Sun, 28 October 2012 20:32 |
carguy wrote on Sun, 28 October 2012 10:59 | Matt Colie wrote "Silicon grease is dielectric grease".
One word of caution and to, hopefully, eliminate some confusion - there is heat transfer silicone product that has the consistency of grease and we use it to between the center of the ignition module and the distributor on our HEI systems. I bought a small tube of this heat transfer silicone at my local Radio Shack. It is is NOT dielectric grease.
At the Amanna rally Dick Paterson recommended that we use the dielectric grease where the 2 screws attach the ignition module to help the ground connection.
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Dielectric grease in non-electrically conductive.
http://en.wikipedia.org/wiki/Dielectric
For this reason I can not understand why one would want it on the mounting screws grounding something. Basically dielectric grease is an insulator. This is why we use it on things like spark plug boots. Lubrication and sealing without electrical conduction.
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Ho Boy....
Everybody is correct, but not everybody has the plan....
You had to listen to Dick P carefully. He was clear and correct.
Technical and long - you were warned....
Let's go back to about 1958 and the first power transistors on T03 cases (the diamond shape with two screws). They knew that heat was a problem, so the mounted the junction on the heavy plate and screwed the heavy plate to an aluminum heat sink (the thing with fins) and they still burned up (actually, the juntcion melted in overheat). During studies, they found the the production devices did not have the milled flat bottom that the lab devices had (Gee!). This caused an heat dam (air gap) (something engineers had used for years to prevent heat flow) to be created between the device and the heat sink (0 5h1t!). That heat dam needed to be breached. First they used a conventional grease and it ran out as soon as the device got hot (see comment above). Then they tried a lithium grease. It didn't run out, but it had too high a film strength and more then half of the assemblies did not have effective electrical conductivity to the heat sink (see KenB's remark).
Someone remembered that during WWII there had been synthetic greases made with a silicon base. These greases were very stable, but had near zero film strength and were useless as a lubricant. The first heat sink grease (at first called thermal coupling compound) was born. It was clear and nasty to get off your fingers. It beat nothing by a whole lot, but was far from perfect. Someone suggested using the silicon grease as a carrier for a material that was highly thermally conductive but could not be handled as it existed. I believe they first used magnesium-oxide (that is what I remember), but that was so reactive with the aluminum that it didn't last very long.
Then along came barium-titanate (invented at Bell Labs in Murry Hill NJ), a known di-electric with good thermal conductivity but exists only as a crumbly powder. That is the white stuff you see today in heat sink compound. Heat sink compound (or grease - if you prefer) is highly di-electic and very stable, but still nasty to clean off your fingers.
In the mean time, it was discovered that these silicon greases did not ever interfere with electrical connections (remember KenB's remarks) because of their near zero film strength, but since they were so stable, they hung around in the voids of a joint and excluded moisture and oxygen.
The problem with the Ba-Ti loaded silicon grease is that the Ba-Ti is still di-electric and if it is in a connection that needs to conduct current, you may end up Second-On-Line (SOL) for a good conductive joint.
Now, does the reason that Dick said used heat sink grease, but don't get it on the ends of an HEI module make sense?? And, use Di-electric grease on the other connections and joints??
I'm going to bed.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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Re: Silicone Grease [message #188603 is a reply to message #188601] |
Sun, 28 October 2012 23:47 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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No. We were talking about electrical conductivity not heat conductivity. Why would you grease the screws with a different dielectric compound if you want to make them conduct better electrically. I see no difference in the electrical conductivity of the screws no matter which dielectric grease you use. They both are an electric insulator. Luckily the screw threads still manage to make an electrical connection so who really cares.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Silicone Grease [message #188605 is a reply to message #188578] |
Sun, 28 October 2012 23:54 |
midlf
Messages: 2212 Registered: July 2007 Location: SE Wisc. (Palmyra)
Karma: 1
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Senior Member |
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Ken Burton wrote on Sun, 28 October 2012 19:32 | Dielectric grease in non-electrically conductive.
http://en.wikipedia.org/wiki/Dielectric
For this reason I can not understand why one would want it on the mounting screws grounding something. Basically dielectric grease is an insulator. This is why we use it on things like spark plug boots. Lubrication and sealing without electrical conduction.
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The main reason to use it on those screws is to prevent oxidation/corrosion. It does this by excluding oxygen and moisture. There are very few truly conductive greases and most are megabucks as they are usually a grease with a silver filler.
When the screws are tightened down the grease is squeezed out where the metal to metal contact is made. Many types of grease can be used to prevent this oxidation/corrosion, even common Vaseline. However there are special compounds, silicone and non-silicone, that do a better job. I used the word "compound" as some of these electrical oxidation inhibiting "greases" have very little lubrication properties.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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Re: Silicone Grease [message #188608 is a reply to message #188605] |
Mon, 29 October 2012 02:48 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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I think you missed the point. They are already using the normal heat sink dielectric grease on the bottom of the module. Now they want to use a different dielectric grease on the screws. Why change?
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Silicone Grease [message #188667 is a reply to message #188633] |
Mon, 29 October 2012 17:35 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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rf_burns wrote on Mon, 29 October 2012 10:51 | The mounting screws used on TO3 etc transistor cases always get coated with heatsink grease while reassembling the circuit. My 35yrs experience is that it seems seal out water and oxygen just as well as any. The screw threads and head are going to get metal to metal connection even with the grease present. Sealing out corrosion and oxidation with grease maintains the connection.
We have some copper paste which we use on the connections of lightning surge suppressors and grounds which is very conductive.
I don't think you'd actually want something conductive as it would likely eventually migrate onto other connections and short out the module connection.
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That is what I would use if I were worried about the electrical connection. Fortunately I'm not worried about it. Another choice might be copper based anti-seize.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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