thermal compound as anti sieze? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 02:48:29 am
content: I have stainless fasteners going into aluminum in a welding fixture. I was thinking to use MX4 as anti sieze, to break up the discontinuities in the thermal path due to the bolts and also to prevent it from locking up.Think it will work? or is this a bad idea?

author: KE5FX
author_rank: Super Contributor
timestamp: July 09, 2023, 03:17:36 am
content: GPT4 actually yields a fairly decent answer:Quote

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 03:44:22 am
content: Where does that thing get its basis from?Maybe I should be more specific:contents1) silicone oil2) aluminum powder3) silver oxideWhat base does a real anti seize use then?whats it missing or what should it have instead?

author: beanflying
author_rank: Super Contributor
timestamp: July 09, 2023, 04:27:29 am
content: Lookup Galling and some steps to minimise it Helicoils or using Nutserts are good options too.https://www.metalsupermarkets.com/what-is-galling/#:~:text=Applications%20with%20ductile%20metals%20placed,undergo%20as%20they%20are%20torqued.Just buy a quality anti seize if you are worried one good option is Loctite LB 8009 but most heavy duty industrial products will work fine just look at their datasheets for Aluminium and Stainless use if in doubt.Good reasons NOT to use thermal compound is they set up rockhard when exposed to even lower heats before you get to them not being very good at what you propose using it for.

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 04:52:57 am
content: I assume the problem is that the silicone oil can evaporate. Does it mean that the vapor pressure and boiling point is too low?What solutions are there to this problem. How do you devoltalize oil?It sounds like there is a pretty specific crux here.

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 04:56:19 am
content: you know what i will do a experiment with a deep hole, bolt and a acetylene torch. I will roast a few samples to see how it behaves when totally over heated. I think the only technicality is if its a through hole or just a hole. I think I have a few pieces of stock laying around.

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 05:01:20 am
content: and for low temperature applications I wonder if a gasket would keep the grease in tact to prevent the liquid part from evaporating if that is the case. I don't think the silicone oil can react with the inorganic materials or polymerize. Maybe.But I see the old HP transistors still have silicone oil under them and its like 60+ years old.is the key to anti sieze the heavy naphthalene oil compounds?

author: Gyro
author_rank: Super Contributor
timestamp: July 09, 2023, 09:34:05 am
content: Why not just ordinary (Copper) anti sieze compound? It's hight temperature tolerant and works fine for things like steel bolts going into Aluminium alloy brake calipers in exposed conditions.

author: coppercone2
author_rank: Super Contributor
timestamp: July 09, 2023, 05:46:55 pm
content: I kinda wanted to know if anyone knew what the magic ingredient is because they look largely the same. I think its a higher melting point oil.

author: tautech
author_rank: Super Contributor
timestamp: July 10, 2023, 08:55:15 am
content: Quote from: Gyro on July 09, 2023, 09:34:05 amMixing copper and alloy is not a good idea ever.Went away from copper based antiseize of any brand after discovering copper compounds can compromise high tensile steels.Use only nickel based antiseize now, Loctite 76754

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 10, 2023, 12:22:21 pm
content: No. It is abrasive, not lubricating.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: July 11, 2023, 07:13:08 am
content: alright I got nickel anti seizeI figure it will be pretty damn dry if its used for welding but I don't need alot

author: thm_w
author_rank: Super Contributor
timestamp: July 13, 2023, 09:49:14 pm
content: MX4 just seems expensive compared to cheap anti-seize (copper or mixed), if its used often.Quote from: tautech on July 10, 2023, 08:55:15 amCitation?76764 is graphite based, 77164 is nickel/aluminum based, don't know what 76754 is, can't find the number.Quote

author: tautech
author_rank: Super Contributor
timestamp: July 14, 2023, 11:33:48 am
content: Quote from: thm_w on July 13, 2023, 09:49:14 pmSorry can't find it, looked and looked.AFAIK it was based on hydrogen embrittlement of HT fasteners from Molybdenum disulfide usage.However none of the antiseize datasheets show that as being used these days.....maybe formulations have changed.

author: coppercone2
author_rank: Super Contributor
timestamp: July 15, 2023, 11:05:18 pm
content: sulfide does something to the metal to make it absorb hydrogen which is generated by corrosion from what I understand

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2023, 05:08:43 am
content: Quote from: coppercone2 on July 15, 2023, 11:05:18 pmYep, it's a type of Stress corrosion cracking (SCC)https://en.wikipedia.org/wiki/Stress_corrosion_cracking