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Old 11-03-2018, 01:04 PM   #26
68Gold/white
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Re: Best fuel line thread sealant?

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Originally Posted by HIGHWAY BY THE SEA View Post
Here is what I was using. It looks uncannily similar to what is pictured in that link.
I ended up doing what I said with cutting the old metal line end and splicing it with the rubber hose (temporarily).


Oh well...I went to parts store, they did not have what I was looking for...

If you look inside the carb fitting, some of the inverted seats in the inlet nuts were smaller than one would think.

I believe (as others have stated...) that the taper on the fitting you installed, and inverted seat are not touching to make a seal.

You MIGHT be able to grind the end of the threads down (make the end flat)some to make those 2 pieces meet...the might part is some what iffy. I believe your new fitting is made of steel ( a magnet will tell). It may not mate together with the inverted seat in the carb fitting.......

The steel tubing works better because the flared end inside the nut is some what soft and pliable, allowing the inverted seal...so thatm,ight be your only way to go, for a while. Using 2 clamps is a good idea, I usually always use 2 clamps. if possible...
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Old 11-03-2018, 01:51 PM   #27
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Re: Best fuel line thread sealant?

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Oh well...I went to parts store, they did not have what I was looking for...

If you look inside the carb fitting, some of the inverted seats in the inlet nuts were smaller than one would think.

I believe (as others have stated...) that the taper on the fitting you installed, and inverted seat are not touching to make a seal.

You MIGHT be able to grind the end of the threads down (make the end flat)some to make those 2 pieces meet...the might part is some what iffy. I believe your new fitting is made of steel ( a magnet will tell). It may not mate together with the inverted seat in the carb fitting.......

The steel tubing works better because the flared end inside the nut is some what soft and pliable, allowing the inverted seal...so thatm,ight be your only way to go, for a while. Using 2 clamps is a good idea, I usually always use 2 clamps. if possible...
I may later try to use those copper bushings or steel lines. Maybe both, because I am JINXED anytime I try to connect any type of liquid-containing threaded pipes. They ALWAYS leak!!!!!
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Old 11-05-2018, 09:22 AM   #28
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Re: Best fuel line thread sealant?

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I may later try to use those copper bushings or steel lines. Maybe both, because I am JINXED anytime I try to connect any type of liquid-containing threaded pipes. They ALWAYS leak!!!!!
I have seen those copper bushings. The ones I am familiar with are for AN fittings. I have never seen them offered for inverted flare stuff ( I worked in a parts store, way back), but I have obviously NOT seen everything...

LOL, I think the race car person needs to come over and bend up a piece of steel line!!!
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Old 11-05-2018, 10:31 AM   #29
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Re: Best fuel line thread sealant?

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I have seen those copper bushings. The ones I am familiar with are for AN fittings. I have never seen them offered for inverted flare stuff ( I worked in a parts store, way back), but I have obviously NOT seen everything...

LOL, I think the race car person needs to come over and bend up a piece of steel line!!!
HA! Maybe, but I honestly do not know him all that well. I happened by his house when I was walking one day, and stopped to talk with him about his race car that he always works on in his yard. That was when I asked him for assistance in showing me how to set TDC and install a HEI in my GMC. He went beyond that by doing most of the work while my son and I assisted and listened carefully to his instructions. All three of us were under that hood! He was nice enough to do that for a neighbor that he does not really know. Great guy!
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Old 11-05-2018, 10:35 AM   #30
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Re: Best fuel line thread sealant?

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Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to achieve a mechanical seal with the threads.
"Thread seal tape (also known as PTFE tape or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads."

You might be correct about how YOU use use, but it's still properly called PTFE Thread Seal Tape. I've been calling myself a plumber for over 40 years and selling sealants longer than that!

The tape is intended to seal in SPECIFIC applications, though in reality most applications people try to use it on here wind up being a flare or compression seal that the threads have no role in doing anything except clamping anyway.

So you're right that people here shouldn't call it thread seal the way they use it, but it still is called that, and particularly in LPNG, it's meant to seal in some cases.
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Old 11-05-2018, 10:54 AM   #31
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Re: Best fuel line thread sealant?

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"Thread seal tape (also known as PTFE tape or plumber's tape) is a polytetrafluoroethylene (PTFE) film tape commonly used in plumbing for sealing pipe threads."

You might be correct about how YOU use use, but it's still properly called PTFE Thread Seal Tape. I've been calling myself a plumber for over 40 years and selling sealants longer than that!

The tape is intended to seal in SPECIFIC applications, though in reality most applications people try to use it on here wind up being a flare or compression seal that the threads have no role in doing anything except clamping anyway.

So you're right that people here shouldn't call it thread seal the way they use it, but it still is called that, and particularly in LPNG, it's meant to seal in some cases.
regardless of what you call yourself, Teflon tape is NOT a sealant. I'm not a plumber & not gonna get into a pecker measuring contest with you, but I do work for NASA and know a lil' bit about sealing pneumatic and hydraulic systems, specifically on flight hardware.
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Old 11-05-2018, 11:22 AM   #32
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Re: Best fuel line thread sealant?

Give me an RO number you order it under at NASA. What's it called, Willie? Sealant.
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Old 11-05-2018, 11:27 AM   #33
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Re: Best fuel line thread sealant?

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HA! Maybe, but I honestly do not know him all that well. I happened by his house when I was walking one day, and stopped to talk with him about his race car that he always works on in his yard. That was when I asked him for assistance in showing me how to set TDC and install a HEI in my GMC. He went beyond that by doing most of the work while my son and I assisted and listened carefully to his instructions. All three of us were under that hood! He was nice enough to do that for a neighbor that he does not really know. Great guy!
Almost all parts stores sell steel tubing that is flared on both ends with the flare nuts already installed, in different lengths. I would like to think that the carburetor end is the same fitting.

You can take a close measurement and get a piece that is slightly long thatn what you need. You can generally make the bends work to make connections on both ends. Not particularly easy, might buy 2 pieces (I usually do, and I have done this too many times, experience wise...). Mr race car might be able to gitterdone easily! Then I would place the inline fuel filter in the hose feeding the pump...

Did you ever find center caps for your aluminum wheels??? Those look to be Western (Brand name) turbine wheels. Might have to measure the hole size and go from there. Not sure if Western still makes aftermarket wheels. An internet search might do the job...I prefer rally wheels...although those turbine wheels would look better with some TLC, and polishing the smooth surfaces. THere are folks that restore wheels, your's wouldn't need much, but some of those companies don't know when to stop charging for their services...
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Old 11-05-2018, 11:30 AM   #34
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Re: Best fuel line thread sealant?

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Give me an RO number you order it under at NASA. What's it called, Willie? Sealant.
NASA doesn't use RO numbers, sorry. But I can tell you that I just did a quick search and out of about 60-65 line item descriptions for TEFLON TAPE or PTFE, the word SEAL or SEALANT was not in any of them.
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Old 11-05-2018, 12:16 PM   #35
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Re: Best fuel line thread sealant?

If you won't be specific I can't help you. There is a ptfe film tape used as a thread lubricant, but it's different from the thread sealing tape pictured here.

As for the stuff in this thread, https://en.wikipedia.org/wiki/Thread_seal_tape
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Old 11-05-2018, 12:43 PM   #36
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Re: Best fuel line thread sealant?

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If you won't be specific I can't help you. There is a ptfe film tape used as a thread lubricant, but it's different from the thread sealing tape pictured here.

As for the stuff in this thread, https://en.wikipedia.org/wiki/Thread_seal_tape
I don't recall asking for any help. PTFE tape, regardless of name its sold under, is NOT a proper sealant for mechanically sealing threads.
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Old 11-05-2018, 12:56 PM   #37
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Re: Best fuel line thread sealant?

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Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to acheive a mechanical SEAL with the threads.
Alright, I sure don't want to hop in this or see it continue on. But in the quote above it sure looks like a contradiction. Ok, so it's a component used in creating a seal. Is the tape a seal? No. Are the treads a seal? No. But Teflon tape used on threads creates a seal. The fact is it doesn't hurt to use it in this case, even if it's belts & suspenders. What is really needed is a correct fuel line.
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Old 11-05-2018, 01:04 PM   #38
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Re: Best fuel line thread sealant?

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I don't recall asking for any help. PTFE tape, regardless of name its sold under, is NOT a proper sealant for mechanically sealing threads.
Wait, which kind isn't for thread sealing? The thread sealing kind or the film kind? Because there are two different types. See I was going to be all pedantic and helpful and give you an out whereby you're probably thinking of ptfe friction reduction film tape, but you doubled down, so... oh wait, I already did. But you're still a solid red X in the wrong column today.

I'll just leave this exerpt from 3M Part Number 48, their teflon thread sealant tape, which explains how it should be used. Reader can decide if what you're saying jives with the manufacturer:

"Scotch® Thread Sealant and Lubricant 48 is a white unfused plastic film made of polytetrafluoroethylene (PTFE). This fluorocarbon resin film tape designed to provide a leak-resistance seal when used as a pipe thread sealant."

I can guess the next steps, so I'll leave them to the reader as an exercise and take my leave... I don't personally use any of the stuff in fuel applications, for what its worth. Maybe on bushings and other tapered-thread stuff. Can't think of anywhere its under pressure through, in stock form I think it's all taper or clamp.
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Old 11-05-2018, 01:47 PM   #39
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Re: Best fuel line thread sealant?

ok bud. you win, you got the last word.
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Old 11-05-2018, 02:38 PM   #40
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Re: Best fuel line thread sealant?

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Did you ever find center caps for your aluminum wheels??? Those look to be Western (Brand name) turbine wheels. Might have to measure the hole size and go from there. Not sure if Western still makes aftermarket wheels. An internet search might do the job...I prefer rally wheels...although those turbine wheels would look better with some TLC, and polishing the smooth surfaces. THere are folks that restore wheels, your's wouldn't need much, but some of those companies don't know when to stop charging for their services...
Not yet! I sure would like to though! The powder coating is perfect, but the lack of center cap is very noticible.
I just sold my Rally wheels to a board member!
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Old 11-06-2018, 04:39 PM   #41
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Re: Best fuel line thread sealant?

Teflon tape does serve to lubricate threads. But not made for sealing? That is a new one. It is designed and used for that very purpose millions of times every day. Grades depending on application. Red for larger joints. Yellow for fuels, Green for sealing oxygen systems, and so on.
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Old 11-07-2018, 12:24 PM   #42
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Re: Best fuel line thread sealant?

There are several types, as you note. It's quite possible that Willie is using a style intended only to prevent galling, and that has nothing to do with sealing. That's why I asked for the RO or part number early on to look it up instead of guessing.

I think the best answer is "it does both" but there are only certain applications where it's is appropriate as a sealant.

95% of the people using it on the threads have no idea that the seal is from a 45 or 37 degree tapered flange and not the threads anyway! Other than where your pipe nipple screws into the intake manifold for your heater hose... not many places.
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Old 11-07-2018, 12:30 PM   #43
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Re: Best fuel line thread sealant?

Good info Dave!
Far too many people believe that if it has threads it needs sealer.
And the same people use a whole tube of silicone sealant where a thin bead is all you need.
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Old 11-07-2018, 12:34 PM   #44
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Re: Best fuel line thread sealant?

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Originally Posted by HIGHWAY BY THE SEA View Post
Not yet! I sure would like to though! The powder coating is perfect, but the lack of center cap is very noticible.
I just sold my Rally wheels to a board member!
Hey, Google, Western wheels center caps, you may find an answer to your center cap situation....
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Old 11-07-2018, 04:18 PM   #45
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Re: Best fuel line thread sealant?

OK, shouldn't need to use any sealant, as it is a single fare. I mean how long has these trucks been on the road with out a fuel leak, you would think there would be a recall by now.

Pulled a old carb off the shelf, to take the fitting apart, first wrench (pipe) started to round out the nut, so I grabbed one of my new wrenches, and it grabbed the shoulder much better, had to tap it with a wooden handle. That sucker was on there!!!!

[url=https://flic.kr/p/QALDQS]20181107_145137

After both the adapter and fuel line were off, there is no obvious reason why this fitting should leak, unless the flair is cracked. The PO did use teflon tape, as there is still remnants of it on the fuel line

[url=https://flic.kr/p/29XW22d]20181107_145056

JMHO, but there should be no reason to use any sort of teflon with fuel as I believe the fuel breaks it down.....use it on your kitchen faucet
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Old 02-04-2019, 04:06 AM   #46
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Re: Best fuel line thread sealant?

In case this is still up for discussion. Try "lapping" the inverted flare portion of that brass fitting or any flare type of joint. How I usually go about it when I am either bending a premade length of steel tubing with tube nuts already installed, or creating a new inverted flare on a piece of steel tubing is: first use a tubing cutter. Take a rat tail file or round chainsaw file and ream the i.d. of the tubing. Then take a fine cut flat file and put a slight chamfer or bevel on the o.d of the tubing.(really only necessary for double flaring of lines.) Then put a thin smearing of high pressure wheel bearing grease on the conical flaring die.(also in tube bending channel if making a bend, it allows smooth operation of the bender and flaring die.) Onve the flare is made wipe with a rag, grab a piece of 1500 or 2000 grit paper and use your finger tip to work the flare smooth,wipe again and your done. On double flares I put a little water on the sand paper to help cut the seam joint down a little faster. But same result. Oh, and now I ALWAYS put those store bought premade pieces into my flaring block and "seat" the flaring die to ensure the flare is concentric. Meaning just enough pressure to ensure it's even. Or another suggestion if it's possible, is to make the flare nut joint up by hand then rotate the tubing into the joint, once you cant turn it anymore back it and the nut off a 1/4 turn then the tube a 1/4 turn beyond that and retighten by hand. I do this a couple of times at different spots on the tube. In my opinion, ever since I began doing these simple quick things, i have yet to have a leak. It's also important to use 2 wrenches when tightening a flare joint and as long as the wrenches are the correct size, dont be afraid to put some torque into it. If you start rounding the nut off, then you dont have the right wrench or the tube nut is cheap.
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Old 02-04-2019, 10:57 AM   #47
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Re: Best fuel line thread sealant?

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Teflon tape is NOT a sealer. It's purpose is to lubricate the threads in order to torque to proper specs without galling and to achieve a mechanical seal with the threads.
^^^^^^^^^^^This is 100% correct^^^^^^^^^^^^^^^^
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