Scrambler82 Posted June 3, 2017 Share Posted June 3, 2017 During all of the rig-a-marole... of brass fittings and piping, I have come away with two things, don't order fittings on-line unless you know what you are going to get AND the biggy... drum roll... Propane requires a different Thread Tape ! The question is, "What is the difference in Thread Tape, Propane vs Regular Thread Tape vs what ever else is out there" ? I have used regular Thread Tape for a long time, I admit, never on Propane fitting but only because I have never assemblies anything requiring Propane, so I was and still am a little ignorant to the differences. I do know sometimes regular thread tape doesn't work well. Can this special Propane Tape be used on regular threaded fitting used in other applications, i.e. Water, diesel, gasoline, etc, etc ? So many questions for an old guy, I think this is something that should have come up earlier in like, lol ! ltr Quote Link to comment Share on other sites More sharing options...
stockmaker Posted June 3, 2017 Share Posted June 3, 2017 Your question got me thinking, I believed that the yellow gas tape was a different composition than the white tape, but an on line search came up this link http://allthumbsdiy.com/plumbing/when-to-use-ptfe-teflon-yellow-or-white-tapes-or-pipe-dope which says it is twice as thick as the white tape and that seems to be the only difference. I don't know what to say about using it on gas and diesel lines, the only thing I found for sure was that it is suggested you only use tape on NPT male threads. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 3, 2017 Share Posted June 3, 2017 That doesn't say it's twice as thick. It says it has double the density---very different things indeed! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 3, 2017 Share Posted June 3, 2017 I've stopped using tape on propane threads, I use paste thread dope for gas. Fast, easy, effective and can't leave tiny little shreds to plug orifices. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Scrambler82 Posted June 4, 2017 Author Share Posted June 4, 2017 5 hours ago, Frosty said: I've stopped using tape on propane threads, I use paste thread dope for gas. Fast, easy, effective and can't leave tiny little shreds to plug orifices. Frosty The Lucky. That was my thought too and I believe the paste seals better with less hassle ! I also found out a little trick in applying the tape, no one told me, it was like a light dawned on Marblehead, (Northeast MA joke), if you apply the tape too low it overlaps the threaded portion, allowing the excess,to come off and block all kinds of stuff, if you keep the tape back one thread it will work flawlessly... What a good boy am I ! I have been doing it wrong for a long time and just got it while putting tape on the propane piping system. The next two questions are... 1) Hour much Thread Tape should you apply for the proper seal ? I use two wraps. 2) How do you determine the proper tightness for a fitting ? My present method is tighten, test for,leaks, tighten again if necessary ! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 4, 2017 Share Posted June 4, 2017 2 wraps clockwise! If the fitting splits it's too tight. It's been so long since I read about doing plumbing and brass fittings in jr. high general shop class IIRC. Hand tighten then + Deleted BEFORE I got it WAY wrong!! Ever have one of those head slapping moments? Happily I had one of those BEFORE posting what I just deleted. I Googled how tighten plumbing fittings. And here you are. https://diy.stackexchange.com/questions/12670/how-tight-should-threaded-brass-pipe-fittings-be Okay, on the count of three, you my friend Scrambler and I will simultaneously slap ourselves on the forehead while saying DUH . . LOUDLY! Ana ONE, ana TWO, and . . . a. . . THREE! SMACK!! Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Scrambler82 Posted June 4, 2017 Author Share Posted June 4, 2017 So after reading this and other things AND always have thought that the Tape was more of a lube than sealer, I am still confused. I also always thought Pipe Dope, was more of a sealant than the tape ! I too, as stated, use two layers of stretched Tape, seemed to have always worked. Who is really going to count either the number of threads or the number of turns after seating the fitting... I don't, I am more a feel kind of guy ! I guess I will keep doing the tighten, test, tighten more if necessary procedure, I will call it the "TTT Procedure" ! Quote Link to comment Share on other sites More sharing options...
Scrambler82 Posted June 4, 2017 Author Share Posted June 4, 2017 4 hours ago, Frosty said: Ever have one of those head slapping moments? Happily I had one of those BEFORE posting what I just deleted. I Googled how tighten plumbing fittings. And here you are. https://diy.stackexchange.com/questions/12670/how-tight-should-threaded-brass-pipe-fittings-be Okay, on the count of three, you my friend Scrambler and I will simultaneously slap ourselves on the forehead while saying DUH . . LOUDLY! Ana ONE, ana TWO, and . . . a. . . THREE! SMACK!! Frosty The Lucky. Frosty, I like asking questions just to see the answers given and sometimes to bring awareness to a thread or site forum where the same question is never asked but maybe should be. No head slapping on this end ! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 4, 2017 Share Posted June 4, 2017 5 minutes ago, Scrambler82 said: Frosty, I like asking questions just to see the answers given and sometimes to bring awareness to a thread or site forum where the same question is never asked but maybe should be. No head slapping on this end ! WHAT?! Our synchronized head slaps didn't happen? I am just so very VERY disappointed in you. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Scrambler82 Posted June 4, 2017 Author Share Posted June 4, 2017 Sorry for your disappointment, the main thing is to try and stay ahead of the curve even though people may think you are behind it. Yes there is a lot of info and videos on the web, too much maybe. It is funny that a lot of the info suggests use of a thread dope type sealant, not the tape and in a lot of the answer forums no one can agree to a correct method, some say the say thing but a little different. Anyway, thanks for responding, if I get too many leaks I will take it apart and use a thread dope ! Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted June 4, 2017 Share Posted June 4, 2017 I have always preferred the tape over pipe gunk. I felt that both of them had the potential to make a mess in the gas jet, if I wasn't careful, and that the gunk could also make trouble because it left traces in the female thread of the gas pipe, after the MIG tip was removed; this in the face of several instances of shreds left in the pipe from the tape doing just that. I was mistaking my distaste for the potential lack of control inherent when using the gunk as best proof, in the face of of continuing evidence to the contrary. Care must be taken with either product, but the facts favor gunk over tape, despite my feelings on the matter. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 5, 2017 Share Posted June 5, 2017 You pipe compound the mig tip threads? Am I missing something I shouldn't? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
stockmaker Posted June 5, 2017 Share Posted June 5, 2017 I had to tape my mig tip threads as they were leaking badly (compressed air test). It made a big difference for me when tuning the burners. Actually it was not the mig tip that was the problem it was the brass fitting that I had taped. It was either too loose to begin with or had warn down with all the testing I was doing. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 5, 2017 Share Posted June 5, 2017 Okay, that's an easy one and precisely why I specify taking the drill bit used to pilot for tapping 1/4"x28 " with you when you pick out fittings. Use the drill bit as a "Go, no-Go" gauge. If the bit won't fit in the fitting it's a go (good,) if it slips in without side lash it's a go (good.) If the bit has ANY sideways movement the hole is too large to thread. It's a "NO-Go" (BAD) The mig tip won't tighten, it'll wobble and leak like a sieve. In the Illustrated directions also I mentioned that you have to use the drill bit appropriate to the thread size of the mig tips available to you. I'm repeating myself in case. For normal usage the through hole size in brass fittings isn't important so long as the specified flow rates are met so there's variation. Too small for the drill bit is perfect, chase it with the drill bit and it's the correct size for good threads. This would be a major flaw in buying fittings online. I hadn't really thought of that, might have to come up with an alternative. Mike? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted June 5, 2017 Share Posted June 5, 2017 There is no mystery here. Pipe threads are tapered, so that seals aren't hard to attain. MIG tip thread, and the matching female thread in a burners gas tube or brass fitting, are parallel thread. They must be sealed with gas rated tape, gas rated pipe gunk, or a gasoline tolerant "thread locker." Yes, thread locker; there are two kinds; those intended to be permanent, and those intended to allow disassembly of the part (with some effort. I first started considering thread locker, after dealing with the black variety found on imported torches and burners. New torches can be unscrewed, with some effort, but on old torches, the parts might as well be brazed together. Kind of reminds me of different kinds of thread locker. And so, thread locker would be my first choice for use with a bad joint between fitting and MIG tip. Frosty, Why not employ pipe goop on MIG tips; it only needs the same extra care that gas rated Teflon tape demands, or in either case, we will end up with a mess inside the gas jet. Once we accept that stricture, I think it is not as likely as the tape to cause trouble. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 6, 2017 Share Posted June 6, 2017 A couple reasons: First, properly tapped the tips bottom out on the shoulder and don't rattle. What difference does a truly minor leak matter in that position in the burner? The jet is more or less open compared to a how much can leak in that joint. Still a little goop or tape would eliminate even a minor unimportant leak, why not. The length of threaded section if very short making tape much more likely to leave a bit right where it can do the most harm. Goop on such a short section can be "plowed" in front of the male section and once again end up IN the gas channel where it'll do the most harm. But hey, pipe compound isn't fluid enough to be blown like a fluid let alone blown loose. Is it? Not back away from the burner it isn't but even if your burners aren't really subject to chimney effect that part of the burner will get hot enough to make the goop liquid. Even with gas flowing it's exposed to strong IR up the burner tube and the propane isn't flowing enough to cool much of anything. I could be entirely wrong but I've never had what can leak from the joint between mig tip and the fitting effect anything. It's directly in the flow of intake air and gets blown into the forge where it belongs. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted June 7, 2017 Share Posted June 7, 2017 I think it varies quite a bit between designs. Linear burners don't seem to be bothered with minor gas leaks in this area, but Mikey burners will not tolerate the slighted leak. Quote Link to comment Share on other sites More sharing options...
timgunn1962 Posted June 7, 2017 Share Posted June 7, 2017 If you are sizing your gas jets to get the mixture you want, either by altering the hole diameter or by altering the length of the jet, you'll need consistency. In theory, if you have a leak that is repeatable so that every time you take the jet out to modify it and put it back in, the leak remains the same, there is no problem. As soon as the leak becomes a variable that affects the mixture ratio, it will play merry games with your burner tuning. In practice, ensuring your leak is consistent would be both onerous and pointless. Sensible folk just avoid creating leaks. The tape vs goop argument will go on forever. I made the move to anaerobic sealants about 30 years ago because I found it just did what I needed it to do with no fuss and, very importantly, no leaks. Something I've not seen mentioned much is that using tape needs care and some skill. Whilst it's a long way from brain surgery and can be covered in a 10-minute show-and-do, I'm guessing most of the guys asking the tape or dope? question are doing so because they genuinely have no idea. They won't have had the 10-minutes of one-to-one instruction from someone who knows and are therefore probably best advised to use an anaerobic sealant, just because there is less chance of getting it wrong. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 7, 2017 Share Posted June 7, 2017 Why remove the jet form the fitting to adjust it? Disconnect the fuel line, remove the fitting and the jet is there. The fitting keeps everything aligned. The jig that allows a person to drill and tap the assembly allows repeatability if a complete rebuild is called for. I just chuck it up in my drill press using the flats on the fitting, spin it and trim with a fine draw file. A little practice and it doesn't leave a bur. This is really easy basic metal shop 101 stuff I've gone over many times. Some things are only onerous if you're a sensible bloke I guess. If a person wants to put compound on the threads be careful is all, I suppose that's easier than taking care to drill and tap the fitting. It's not uncommon to need to clean the threads in a mig gun, copper is easy to cross thread so chasing the threads is just a maintenance chore. It's no big thing. If you're having trouble finding mig contact tips with the threads you expect, buy the tap at the welding supply where you get the mig tips. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Mikey98118 Posted June 8, 2017 Share Posted June 8, 2017 On 6/7/2017 at 0:05 PM, Frosty said: Why remove the jet form the fitting to adjust it? Sometimes the adjustment is to substitute a different MIG tip, or to file the tip a few thousandths larger. I've only had to remove a tip for cleaning once in all these years, after a friend used a really cheap propane in his forge for three weeks. I unscrewed the tip and removed a hard sticky little ball of tar. Tim, Thank you for using the term " anaerobic sealant." I did a word search, and up popped the probable answer to a question I've been mulling over for years; what is that hard black part sealant used on so many torches? I now suspect it is thinned out gasket sealant. With a little luck I will be able to come up with the right solvent for it, and be able to disassemble imported torch parts at will! Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 8, 2017 Share Posted June 8, 2017 You really had to reach for that one Mike. Adjusting not changing, two different things. You'd have to disregard simple instructions to make a wrong diameter mig tip mistake. Maybe take a wild guess at what trim by 1/32" increments means or use a hammer and chisel. That falls into the education is expensive category. Even then, unless you picked up contact tips with different threads it's not going to make a difference. Not if the fitting is drilled and tapped correctly it won't. I'm not talking machine shop quality work, a drill press, jig and simple instructions is all. I apologize if what works for me doesn't meet anyone's expectations of what should be. Use tape, pipe dope, solder, braze, whatever suits your fancy. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
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