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Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 7:57 am
by Kykeon
It’s hard for me to find tef-gel locally but there are many copper & aluminum greases.

e.g.
https://www.permatex.com/products/lubri ... bricant-2/

https://eshop.wuerth.de/is-bin/INTERSHO ... E.V0Uo7fmh

My understanding is that tef-gel (which is what the manufacturer recommends) does not contain copper.

I’m not a specialist but I’m worried that the copper in the paste does hurt the aluminum because it is less noble.
Therefore, if grease remains in the aluminum part after the disassembly, it will create some corrosion.

On the other hand, why do these 2 pastes above contain both aluminum and copper.

Does anybody know if any of these products is a viable alternative?
If yes, why doesn’t the contained copper hurt the aluminum of the mast/fuselage?

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 8:33 am
by FrederikS
Do not use anything with copper on aluminum it is meant for steel-steel connections, not dissimilar materials. Normal grease without copper for marine use is fine, get the PTFE loaded versions if you want something that is similar to tef gel.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 8:50 am
by airsail
Look for a product called Thixogrease, http://www.powerupusa.net/index.php/pro ... hixogrease if it is available in your location. I work in aviation and we now use this in joint areas where corrosion has previously been a problem using conventional products. From what I was told it was originally developed for the offshore oil and gas industry.
I'm assembling my foil with it, early days but so far so good.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 12:32 pm
by bacon2109
Try to find a dielectric grease,
if possible, a food grade grease and water resistant, to stop electric current which make corrosion.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 12:49 pm
by Kykeon
Oh! I just realized that I got something wrong...
Thanks for helping me understand it.

I thought that tef gel contains aluminum which gets sacrificed and thus protecting the aluminum of the foil...
So tef gel protects just by isolating?

The guy at the marine shop proposed me to use marine grease with PTFE
I'll keep trying to find tef gel and if I don't manage until my tub runs out, I'll get the PTFE marine grease.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 2:36 pm
by BWD
go ahead and pitch that copper grease out, it's worse than nothing.
Just use a little bit of lithium grease or anti-seize and clean frequently until you get the right product.
Since you're here, you can probably just order tef-gel online.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 4:05 pm
by FrederikS
You should not use lithium grease in marine application. Get either a plain grease for marine use or one with high PTFE content which is basically what Tef Gel is.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Thu Sep 14, 2017 7:30 pm
by TomW
PTFE is the chemical name for the brand name product called Teflon. Tef Gel = Teflon Gel?
Highly likely the same.

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Fri Sep 15, 2017 12:56 am
by Oldman
Some foil Manufacturers recommend tefgel while others advise white lithium grease.
anyone knows which is better? Or practically it's the same?

Re: Copper Aluminum paste as tef gel alternative ?

Posted: Fri Sep 15, 2017 4:54 pm
by FrederikS
Get the one with PTFE. If they recommend grease with lithium they must have gotten bad advice from someone as it is normally not recommended for marine use or for mixed material assemblies.