# Using STL on aluminum conduit threads



## wiz1997 (Mar 30, 2021)

Back when I was working in refineries and chemical plants running mostly GRC, we put Copper-shield on all threaded fittings, conduit and GUA covers.

It was spec'ed out by the engineers.

When running aluminum rigid or installing instruments we used Noalox on the threads.

A couple of years ago I read you shouldn't put anything on the threads of GUA fittings.

The premise was the thread lubricant would act like a gasket and not let the pressure out if there was an explosive vapor ignited inside the conduit system.

Now a days, I have to use a food grade anti- seize on threads due to working in a food processing plant.


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## Almost Retired (Sep 14, 2021)

i dont have the freezing problem down here so i always use STL on all bolts and threaded fittings
there is a severe oxidation problem in comparison lol
continuous high humidity


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## kb1jb1 (Nov 11, 2017)

What is STL and GUA?


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## Almost Retired (Sep 14, 2021)

kb1jb1 said:


> What is STL and GUA?


STL8 is electrical grade grease, it comes in a handy half pint can with brush in lid for smearing it around and small squeeze tubes

because i googled it .... GUA is an explosion proof round junction box made by eaton

by the way you could have googled these questions and looked smarter 
it took me all of 30 secs to find it and longer than that to type all of this


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## wcord (Jan 23, 2011)

I always used STL and didn't seem to have a problem. Even on old installations, the covers came off fairly easy. 
Never saw anyone use something else.


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## glen1971 (Oct 10, 2012)

I use STL as @SouthernCanuck mentioned, plus XP lights (not the glass), bolts into EDSC boxes for switches, to name a few more places. If the lights are in a high heat area, such as over an engine, I use high temp antiseize on them.

Where some get into grief is figuring they need 900 ft. lbs of torque to tighten a cover. STL, hand tight, then back 1/4 to 1/3 of a turn. There is no need to get crazy tight.

Not using it, is a reciepe for disaster that may involve using up to an angle grinder to a Yokagawa transmitter cover and destroying the transmitter. We had specialty wrenches made to undo Div 1 lights that guys forgot STL or overtightened when relamping. What a treat it is using a 24"+ long wrench with two guys 25' up on light.


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## macmikeman (Jan 23, 2007)

Spray can of Lithium Greese. Same stuff, more readily available, easier to apply since it sprays on.


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## glen1971 (Oct 10, 2012)

macmikeman said:


> Spray can of Lithium Greese. Same stuff, more readily available, easier to apply since it sprays on.


It can be a PITA to break free in sub zero temps.


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## Almost Retired (Sep 14, 2021)

macmikeman said:


> Spray can of Lithium Greese. Same stuff, more readily available, easier to apply since it sprays on.


and easy to apply to unintended targets while spraying it

i prefer the brush in the lid
STL8 is like Bril-Cream ..... a lil dab'l do ya
im not sure how many years i have had the same can

i actually prefer it to be no more than a 1/3 full, other wise you get tooooo much at once


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## kb1jb1 (Nov 11, 2017)

Almost Retired said:


> STL8 is electrical grade grease, it comes in a handy half pint can with brush in lid for smearing it around and small squeeze tubes
> 
> because i googled it .... GUA is an explosion proof round junction box made by eaton
> 
> ...


I am boycotting the internet and I hate acronyms.


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## kb1jb1 (Nov 11, 2017)

Almost Retired said:


> STL8 is electrical grade grease, it comes in a handy half pint can with brush in lid for smearing it around and small squeeze tubes
> 
> because i googled it .... GUA is an explosion proof round junction box made by eaton
> 
> ...


I googled it and pages of stuff came up but no electrical trial grease.
St. Louis, standard tesselation language, standard temple library, speed tech lights, it is also a polydectrihedrial inside a sphere. I saw nothing about grease. I also looked up GUA nothing.


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## kb1jb1 (Nov 11, 2017)

macmikeman said:


> Spray can of Lithium Greese. Same stuff, more readily available, easier to apply since it sprays on.


Now I know what lithium greas is. STL ? Did you know what it is?


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## glen1971 (Oct 10, 2012)

kb1jb1 said:


> I googled it and pages of stuff came up but no electrical trial grease.
> St. Louis, standard tesselation language, standard temple library, speed tech lights, it is also a polydectrihedrial inside a sphere. I saw nothing about grease. I also looked up GUA nothing.


Here ya go..
STL2:


https://www.eaton.com/mx/en-us/skuPage.STL2.html



GUA fittings:


https://www.eaton.com/us/en-us/catalog/conduit-bodies-covers-and-outlet-boxes/condulet-gua-and-gur-series-explosionproof-conduit-outlet-boxes.html


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## macmikeman (Jan 23, 2007)

I almost never Google anything. Yahoo......


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## kb1jb1 (Nov 11, 2017)

glen1971 said:


> Here ya go..
> STL2:
> 
> 
> ...


Thank you. I learnt something today. Or is it learned? 
GUA - I usually call them round explosion proof boxes.
STL - I have to check into it. 
What did you Google to find them?


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## glen1971 (Oct 10, 2012)

kb1jb1 said:


> Thank you. I learnt something today. Or is it learned?
> GUA - I usually call them round explosion proof boxes.
> STL - I have to check into it.
> What did you Google to find them?


I used "Crouse Hinds GUA fitting" and "Crouse Hinds STL2".


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## micromind (Aug 11, 2007)

Almost Retired said:


> STL8 is electrical grade grease, it comes in a handy half pint can with brush in lid for smearing it around and small squeeze tubes
> 
> because i googled it .... GUA is an explosion proof round junction box made by eaton
> 
> ...


On the other hand though, posting it in a public forum tells everyone what it is...........


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## wcord (Jan 23, 2011)

kb1jb1 said:


> polydectrihedrial


Try saying that word fast lol


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## wcord (Jan 23, 2011)

I remember when I moved back to Manitoba from Alberta and ordered some 10464 connectors, UNY, EYS fittings and STL, none of the suppliers had any idea what I was asking for.


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## glen1971 (Oct 10, 2012)

And to add.. I've also used STL to help pull wires through an LB. To help with tapping small holes, as i had 3 - 1/4" bolts today that felt like they were cutting new threads as I removed them from a new thermostat. And the odd time I've used it to thread aluminum conduit.


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## kb1jb1 (Nov 11, 2017)

wcord said:


> Try saying that word fast lol


I got that from Scotty on one of the Star Trek episodes. How it is spelled, IDK. But it sounds good. Like a NAQUADAH GENERATOR. They are extremely powerful and could power many EVs for years.


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## kb1jb1 (Nov 11, 2017)

glen1971 said:


> And to add.. I've also used STL to help pull wires through an LB. To help with tapping small holes, as i had 3 - 1/4" bolts today that felt like they were cutting new threads as I removed them from a new thermostat. And the odd time I've used it to thread aluminum conduit.


But can you use it as hair gel? I believe someone said it is comparable to Brylcreem.


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## glen1971 (Oct 10, 2012)

kb1jb1 said:


> But can you use it as hair gel? I believe someone said it is comparable to Brylcreem.


Whatever blows your hair back!


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