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by hilbert42 1294 days ago
"You need about 1.5 wraps of PTFE tape to seal a fitting. Any more is wasteful and asking for leaks"

I would have thought this obvious and it's essentially my experience (and I'm definitely not a plumber). However, I've found that more PTFE tape is needed on old or worn fittings or on ones that have damaged or badly cut threads—or when mating same sized pipes/fittings but each with different threads (yes, that's a desperate brute-force move in an emergency but I've had to force such matings on more than one occasion). In these circumstances, I'll use two or three turns or more often by trial and error—and this changes somewhat depending on whether I'm using thinner white PTFE tape or the thicker pink one.

Of course—not being plumber—it often happens that when I urgently need PTFE tape I cannot find it (it having been filed in some obscure place that I've forgotten about—even though I keep a reasonable stock of it), it's then I fall back to the good old combination of Hessian/burlap jute-type rope (of which there is always some lying around in my workshop) and linseed oil based paint. It's messy and much less convenient combination than PTFE tape but it still works wonderfully well. Moreover, it's more tolerant of the amount applied as the linseed oil actually binds to the pipe surface as opposed to the more 'mechanical' bond of the PTFE.

2 comments

>Of course—not being plumber—it often happens that when I urgently need PTFE tape I cannot find it

Ahh, young padawan, the way of the elder is to buy a roll every time you have a project to do until you have achieved saturation...where there is a lightly used roll of teflon tape in every drawer and on every surface of your workshop and garage.

Ha! I'm no longer a Padawan so, like you, I'm well acquainted with the practice of spreading things around to the point of saturation.

It's not only PTFE tape that I spread around in copious quantities, other notables on the list are screwdrivers (of various sizes and types), superglue tubes (they go off with age anyway), propelling pencil leads, keys, USB and computer cables, USB pen drives, computer mice, adhesive tape, remote controls and any number of useful things.

The trouble is these supposedly inanimate objects come to life in the middle of the night and conspire not to be available when I most need them. Then the moment I've made do by jerry-built means they suddenly reappear! ;-)

When I was a kid, my mom's theory on pencil purchasing was that if she bought enough, the house would be so saturated that you could shake a curtain and a pencil would fall out.
Hum... Clearly, I'm not alone. That's at least some comfort.
Almost every night I pick up 3-5 pencils around the main living area at our house. Somehow there are always dozens of pencils around, but finding one with a working eraser on the end is as rare as finding a unicorn.
The mistake-making side is much larger than the mistake-fixing side. This is a display of great, foolish optimism.
I just bought 24x 6” stainless steel rulers because every time I’d reach for one it’d be across the room at a different desk. Now I can capture a dozen at a time in their remote location for rehoming. Problem solved.

Also on my list of buy too many so I’m never left without: sharpies, microfiber cloths, jumper cables, rice (carbs), frozen sliced sourdough (fancy carbs), pocketable protein/energy bars.

I know, 12" rules are bad enough at disappearing but 6" ones seem as fleeting and ephemeral as the wind.

At least it's nice that one can now purchase them in packs of a dozen or so.

I am glad to be using metric. 150mm and 30cm rulers don't seems to run as fast as theirs us customary unit counterparts ;)
Mine are mainly metric or dual Imperial/metric too. I usually convert to Imperial because most readers are in the US.

If you were to read some of my old HN comments you'll realize defending the metric system in a US environment is pretty much a waste of time.

I recall one debate where some US commentators didn't have a clue about what a comfortable room temperature in Celsius would be. 68F=20C was meaningless to them even though 20C is a standard calibration temperature in lab and scientific work.

Not worth raising the issue.

I was primarily making a joke. But it is indeed a big pet peeve of mine.

I do find it annoying that one country in the world likes to use it's own unit. And that of course they are not as nice to use as the units optimized for science. It is annoying for international communication.

But my real issue is that Americans seemingly lie to themselves by pretending everything can be rounded off to the nearest approximation of US customary units without consequences. And so anything you buy in the USA; unless maybe when manufactured with US customary units; is not the advertised size. Worse yet, this habit of rounding off is also applied to US customary units in many case. Because nothing is ever the advertised dimensions, or the tolerances are just laughably large. Nothing ever fits. That is what I am fighting.

Ask for a 48" long piece of lumber in the USA, you get something +- 1/4" at best (+- 6.35mm). Go to my home country asking for 1.2m will get you something +- 0.5mm. It's cultural.

I unlocked an uncommon DIY achievement last month: I finished an entire 119 foot roll of PTFE tape.
All I have is Teflon tape, but I’ve never finished a roll. I think they sell them in only 3 feet sections now, but still the same spool size.
One has to ask 'finished it doing what'.
Some sort of mummy costume party i'm sure
That’s beyond ’uncommon’, you should get a trophy.
That's only the way of the middle-aged. If you do it with just PTFE tape you'll be fine, but if you do it with all similar sundries, then you'll be oversaturated and once again won't be able to find anything without pawing through piles.
Right, see my reply to jcims but that's not all of matter. One could suppose I'm going senile and perhaps that's true but the fact is that I've been losing stuff like this since before I was a teenager.

I've figured out the problem: my mind is thinking about all sorts of seemingly important stuff all the time but which in fact is mostly garbage, so my subconscious mind handles what my conscious mind consideres as procedural or unimportant. As my conscious and subconscious minds aren't on speaking terms sufficient for my liking I often end up with the problem of lost stuff.

If I consciously tell myself where I've put something then I very rarely forget where it is. The trouble is I don't remind myself to make note often enough.

My own working model is one of complexity building up over time. You can handle it fine as long as you don't have many fields of endeavor, you have plenty of time to periodically focus on them, keep the stuff organized, can fully finish a project and button it up, etc. But then things happen where you're forced to clear out your mental cache, or even screw up your organization/storage system for whatever, and it comes crashing down. Then all the complexity you were managing gets in your way, and the problem snowballs unless you regain some bandwidth and take steps to mitigate the decay.
Right, that makes sense. And my explanation is more complex than I could detail in my comment.

I know I have too many diverse interests—fields of endeavor to quote you—and the older I get the more of them I accumulate. On the one hand having many interests is very useful because it allows me to see and understand common ideas or threads across quite disparate and diverse subjects that otherwise would not have been obvious but the matter of administration becomes a significant problem. Often I've little time to deal with prosaic matters so the mundane is often left to itself (disorder accumulates).

That said, I'm instinctively an orderly and tidy person, as I like to say 'there's a place for everything and everything in its place'. I hate mess and disorder but that doesn't mean that I don't experience it—I do so often for reasons that you mention. However, when entropy/disorder around me reaches a certain 'sensibility' threshold I'm triggered to have an almighty cleanup much to the chagrin of others around who have a more relaxed view of disorder.

Nevertheless, I'm not obsessive about it, sometimes I amaze myself at the level of disorder I'll tolerate. (Reordering things is boring and distracts me from my interests despite the fact that I'm competent and thorough about it. Essentially, the more preoccupied I am with something the higher my toleration for mess and disorder becomes).

Have you ever been diagnosed with ADD/ADHD?
Or you find yourself married and with children, and that final step of regaining some bandwidth becomes structurally impossible to achieve.
It all adds up to what I call the 'overhead of living problem'.
This is the way. It’s also cheap enough that buying a dozen rolls upfront is less effort!
"combination of Hessian/burlap jute-type rope (of which there is always some lying around in my workshop) and linseed oil based paint."

Could you explain that? How do you seal pipe fittings with rope?

Edit: found an explanation. TIL that you can use the fibers just like tape and wrap the threads.

Perhaps if I'd used the proper name what I said may have been clearer. The correct name is hemp rope or plumber's rope but I don't often have that around (not being a plumber) so I use the next best thing available Hessian fabric or its rope equivalent).

Here are some photos: https://www.bunnings.com.au/enduraseal-1m-plumbers-hemp_p012...

https://waropes.com.au/twines/plumbers-hemp/

You wrap the hemp fibers around the threads that have been brushed with linseed oil paint then apply a little more paint to the hemp and then mate the couplings together. This sealing technique has been around at least for several hundred years if not longer.

>> [...] has been specifically designed and manufactured to suit the Australian market and conditions.

That's some hearty stuff, then!

First class BS if you ask me. Hardly anything could be more generic than hemp rope methinks.
That seems hella useful, I'm going to grab some next time I'm down picking up a snag sanga.
You don't need oil, just rope works as well. Every DIY store (at least over here) has loose manila fibre for that purpose. Wrap into the thread, screw it together, done. The not-so-nice problem: It might leak at first. The nice feature: The fibres will soak up water (thats why oil is actually counterproductive), swell up and make a tight fit after half an hour or so. You can even readjust the angle (other than with PTFE tape), it'll just drip for another half hour.
Right, there are multiple variations but they generally work in skilled hands although I learned from plumbers who always used oil (although using oil was always an imperative with gas pipes). Using oil usually negates the initial leaking whilst waiting for the hemp to dampen and swell.

Edit: I agree that using oil is counterproductive with water pipes—initially at least. I was taught by both plumbers and my father (who wasn't a plumber but a mechanical engineer who worked on power station boilers) that using oil is better in the long run as it prevents the hemp from rotting and thus premature failure of the seal. Moreover, using one oil-based method means that a plumber cannot get confused and leave oil off gas connections where it's essential.

(I'd add that when referring to oil I'm specifically referring to linseed oil (even though I've seen some plumbers inappropriately use engine oil) because it slowly polymerizes and hardens even in the absence of air. This adds to the seal's effectiveness and further protects the hemp.)