Teflon Tape on exhaust Mani plugs...

Scaaty

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Read one of the post a ways back on not to use Teflon tape on exhaust manufold plugs and nipples. And the reason is...???
 

michael-lagrange

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Re: Teflon Tape on exhaust Mani plugs...

Good question scaaty, it dosent get that hot ( not like auto manufold ) i have used it there.
 

Bondo

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Re: Teflon Tape on exhaust Mani plugs...

I Believe it's Because,......<br /><br />The Tape is So Slippery, folks have a tendency to Over-Tighten,+ Crack the Cast Housings.......
 

8x56mn

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Re: Teflon Tape on exhaust Mani plugs...

Bodo , that is correct, however you don't need to overtighten and the plug used with tape and dope will always back out no matter how hard the dope gets or how long it's been in place. We use this methode on all jobs weather cast, black or steel.
 

THE BEEF

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Re: Teflon Tape on exhaust Mani plugs...

Teflon tape and pipe dope are used for one thing they lubricate the threads of the pipe fitting.<br />Pipe fittings are cut on a taper and are self sealing.<br />Just tighten it up, don't crank on it. :mad: <br />Beef :D
 

Mischief Managed

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Re: Teflon Tape on exhaust Mani plugs...

Could it be one should not use it on a manifold zinc anode because it will electrically isolate the two parts? Just a thought...
 

Scaaty

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Re: Teflon Tape on exhaust Mani plugs...

I don't know either. I just put on new mans last year, and I do remember in the destructions to use pipe dope only. And don't crank the daylights out of them, thats for sure, as that will stress the cast iron, and cracks wreck yer day. Theres no pressure, so you just need to snug them up anyway.......
 

Scaaty

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Re: Teflon Tape on exhaust Mani plugs...

Originally posted by Mischief Managed:<br /> Could it be one should not use it on a manifold zinc anode because it will electrically isolate the two parts? Just a thought...
Theres no zincs in the exhaust..not that I know of anyway. I have one in my aluminum intake though, and ANY zinc must be metal to metal contact. No dope or tape
 

Bondo

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Re: Teflon Tape on exhaust Mani plugs...

Originally posted by Mischief Managed:<br /> Could it be one should not use it on a manifold zinc anode because it will electrically isolate the two parts? Just a thought...
You Might be Onto Something,........<br /><br />Even though it's Not Anodes we're talking about,.......<br />It IS a Totally Bonded System,.......<br /><br />That's the Why Fors of All the Little Woven Wires that Merc has screwed to every moving piece of the drives,.....<br />I'm Sure that a manifold fitting would Also have to be Bonded,......<br />Just for Electrolysis's(say That 3 times Fast) sake.............. :rolleyes: :D
 

8x56mn

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Re: Teflon Tape on exhaust Mani plugs...

Guys, Teflon is Teflon don't you think?
 

KaGee

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Re: Teflon Tape on exhaust Mani plugs...

Well, my buddy works tool and die. Their engineers forbid them to use tape on any castings. Teflon thread sealant will ooze out of the thread... tape will not. <br /><br />The tape was designed for plastic fittings or plastic to metal fittings. Metal to metal was never the intent.
 

Bondo

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Re: Teflon Tape on exhaust Mani plugs...

Ayuh,......<br />The Tape is really a Sheet of Plastic,+ I can see where you could Loose Metal to Metal Contact,.........<br />Especially some people who Think,.. More is Better....... :rolleyes: <br /><br />And like Keith says,.... The Paste just OOzes around,+ it IS in fact a Metal to Metal Contact...........
 

bruceb58

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Re: Teflon Tape on exhaust Mani plugs...

I bet that if you put an ohm meter up to a fitting and the manifold that was put in with thread tape, you would get zero ohms!
 

tommays

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Re: Teflon Tape on exhaust Mani plugs...

I use a LOT of USA MADE UL approved Teflon Tape Its rated for up to 2" NPT METAL PIPE ( NOT that POS stuff from CHINA they sell at most places now)<br /><br />We pipe a LOT of steam kettels for the last 32 years 5 to 5000 gallon<br /><br />All of the kettels have SS nipples that get couppled to black fittings JUST try and get that to NOT leak with pipe dope without twisting one off :) <br /><br />About the 3rd time you take 17 fittings off to get to the one that fails a pressure test you will be likeing teflon tape USED CORRECTLY just fine<br /><br />And you can never be sure till its got 90 # of steam and all the different metals are done doing there thing :) <br /><br />And then you dump the steam and fill it full of ice water to cool off what you just cooked Pump it out and start pounding in steam to cook the next batch of soap<br /><br />And you will be changeing out the sections of pipe that get chewed up from the wet steam LONG before the tape ever leaks ;) <br /><br />tommays
 

bruceb58

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Re: Teflon Tape on exhaust Mani plugs...

The reason you don't want to use teflon tape on cast iron is because it allows you to over tighten.<br /><br />It is fine for other metals such as copper.
 

8x56mn

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Re: Teflon Tape on exhaust Mani plugs...

"Well, my buddy works tool and die. Their engineers forbid them to use tape on any castings". Teflon thread sealant will ooze out of the thread... tape will not. <br /><br /><br />Well I'm an engineer and my opinion is that Teflon tape fills the voids and yes it does provide lubricant, used with a pipe dope sealant it gives you the best of both worlds. You can do it the easy way or hard way.
 

KaGee

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Re: Teflon Tape on exhaust Mani plugs...

Originally posted by 8x56mn:<br /> Well I'm an engineer and my opinion is...
I realized when making my previous comment that some engineer out there would read and comment. <br /><br />One thing I've learned in my career... seldom do engineers agree totally on anything. Somebody always has (in their mind) a better idea and that's very much OK. It's how ideas evolve.<br /><br />The previous owner of my boat followed your train of thought... on the fuel line to and from the fuel pump. Guess who ended up replacing what looked to be otherwise a brand new fuel pump? Fuel leaking in the bilge. Why, you ask? Loose fuel line connection?? No. Cracks in the casting. He used TEFLON TAPE and DOPE.<br /><br />But y'all can do whatever you want. Doesn't make it wrong, but may not make it right either.
 

8x56mn

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Re: Teflon Tape on exhaust Mani plugs...

Yup, probably I would attribute that to operator error at istallation. I have found that after over 25 years of building automation equipment that it's almost impossible to make everything idiot proof, which is why your friend was told not to allow Teflon tape, because everyone's idea of tight is somewhat different.<br />However I maintain that the design of the material is such that it will prevent leaks if installed correctly with the correct amount of wraps and when used with pipe dope makes a very good seal and remains easily removed at a latter time. The only time that I will not allow TT is on air lines as it has a tendency to migrate into sensitive control valves downstream causing problems. Like you said each there own, hit yourself with a hammer eneough times it feels good when you stop. :)
 

tommays

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Re: Teflon Tape on exhaust Mani plugs...

Kinda funny because MOST of the higher quality air fittings (Festo amoung others)come from the factory Taped :) <br /><br />
A7CF9DEECAB841EF9CF2B5092C4CE26C.jpg
<br /><br /><br />And i can not clean off the cutting oil correctly and blow up most any fitting if i work hard enough at being stupid NO matter what kind of sealent i use<br /><br />tommays
 

KaGee

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Re: Teflon Tape on exhaust Mani plugs...

...because everyone's idea of tight is somewhat different.<br />
Yep, that about sums it all up.
 
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