The Stovebolt Site Forums The Shop Area Engine Shop Heater hose fittings - teflon tape, pipe dope, etc?

A quick google has left me with as many opinions as there are options.

Some say NPT doesn't need other sealant (this makes sense to me). Others swear by anti-seize or Permatex #2.

I'm asking in regard to the fittings in the thermostat housing and the water pump.

Thoughts?

Pipe fittings can use a dab of Teflon paste or tape, careful not to contaminate fluid.

T'stat, heater hose fittings need no sealant, clamping force does the sealing.

I should clarify...I'm asking about sealing the pipe thread of the fittings in the T stat housing and water pump.

JW51,

As you posted, sealant is often not needed with good, clean NPT joints.

However, as EdPruss posted, teflon pipe-paste or teflon tape is a good assurance of a leak proof fit. I use either (whichever one I find first).

I use paste-type pipe dope or Permatex Super 300 brush-on liquid sealer on pipe threads. Sometimes a naked thread has a tendency for seep leaks.
Jerry

I am not a plumber, but my Dad was.

Dad used the old-fashioned green paste pipe dope. He refused to use any of the teflon-based lubricants on pipe thread.

His reason: Pipe thread is tapered. Teflon is an excellent lubricant, and it is easy with the paste to overtighten the joint to the point of damage (splitting). The tape will come apart if not perfectly wrapped, get in the joint; or like the paste, cause the fitting to split.

He did use the teflon tape. He thought it excellent for marking small trees, stakes for a fence, etc. However, where I now reside, we have an abundance of deer, and they will eat the teflon tape; so I guess I don't have a good use for it.

Maybe it could be used to wrap Christmas presents???

Jon.

I have always been told that if its NPT it gets some kind of dope. I wonder why not use High Temp Gasket sealer. If it's good for most things on the engine, seems it would be a nice handy thing to use.

after being in the merchant marines for about 15 years, I have seen chiefs that swear the only thing that will work is the very stuff the previous chief swore wouldn't work. That includes just about every type of sealant you can think of, teflon tape, teflon paste, rector seal, aviation permatex, permatex #2, loctite, and whatever else you could find. And the only thing that was consistent is they all worked. And given you only have 7 PSI at the most. You could probably use biscuit dough for that matter

Jon, Teflon is a good lubricant- - - - -maybe those deer just need a good laxative every now and then!
Jerry

The thought of the deer output after eating Teflon makes me think of a real wormy animal...ugh

I have never used any dope on a transmission NPT plug and never had any leak issues.

Why isn't anything ever black and white?

...most of it is just "trickery" to get you to buy THEIR products. I do believe that there are some "modern" or latter day stuff that is good but is it really better than what worked years ago. Maybe some, maybe not on others. If it works for you then use it. A problem is what worked years ago has been taken off the shelf and replaced with "repackaged goods".
Had the same problem today that I'm talking about. Went to THREE stores before I found the Sanding Sealer I was looking for and been using for over 30 years. Lowes was a joke!

....I can see this getting into "how many times to you wrap the Teflon around the threads? Two, three or more??

i use both teflon tape and the paste. i have never had a problem over torquing /tightening any such. teflon over the paste.

contaminate what ??

''often not needed with good, clean NPT joints.'' ...... and we are talking 50-60+ year old equipment here, yes it can be cleaned but an ounce of prevention ........

my 1¢
do as you wish, it's your rig.

I have built and assembled fuel systems and cooling systems for many years and I always use pipe dope on NPT fittings,you don't and it is going to leak,the only exception is using brass fittings, they can seal without sealant,I personally seal every fitting I install.