Teflon Tape, Loc-Tite, or Threadlock?

RevoXT wrote: I am installing an expansion chamber onto my A-5 later on today, so I was wondering what the best thing is to use on the threads. Alot of guns like Piranha's use Teflon Tape with no problem.. however is Loc-Tite or Thread-Lock better?

First, Loc Tite is a thread locking product. Permatex makes a similar product. Thread lockers are intended to prevent loosening of screws, nuts and bolts from vibration. The Loc Tite name is used generically most of the time. Thread-Locker, a brand name, is a product with which I am not familiar.

Some people claim that Loc Tite type products are not intended to seal fittings in pressure systems. Strictly speaking Teflon tape is also not intended as a sealant. It is a lubricant that allows NPT type pipe fittings to be tightened far enough to seal.  A side benefit of both Loc Tite and Teflon is that they do a very good job of sealing air and CO2 pressure in marker fittings.

Teflon is relative easy to use and if you apply it to the threads about one thread back from the end of the fitting it should cause no problems. See this Marker Trouble? Read Maintenance Archive about the 15th or 16th post on disassembling the power valve. In that post I cover a possible problem with Teflon.

I favor the gel style Loc Tite type products. I cover that also in the link above. I like the gel Permatex because it is easy to apply and seals immediately so you may use the marker as soon as it is assembled. The blue color is a medium strength material so you can remove treated fittings with standard tools. You can also make minor adjustments in the fittings and this gel sealant/thread lock material retains the seal.

Shadowminion wrote: On occasion , I've had problems sealing the hose to the power valve (CVX valve) because of thread irregularities (they looked fine ,but just would not seal) . I used Loctite 242 , medium strength blue , on the male threads of the hose fitting and applied teflon tape as Bruce outlined above , over the loctite and carefully applied a very small amount of 242 on top of the tape to seal any voids in between the valve body and hose fitting . I dont recommend this as a first attempt procedure for sealing , normally teflon tape applied as Bruce A Frank suggested will work 95 % of the time or more . Loc-Tite Corp. and Permatex are sister companys , I'm not sure who owns who and it doesnt really matter but I've seen most of their produts marketed under both name labels . Loc-tite used to make a thread sealant for pipe fittings , #515 , it had the properties of both teflon pipe dope , and the thread lockers . I havent run across that product for quite a while .

If you are remembering that number correctly, 515 is still around. It is designated as a flange sealing form-in-place anaerobic curing flexible product. I didn't see anything in the literature about using it on NPT threads...but that does not mean it wouldn't work well. I have adapted many things over the years that were intended for one type of application, and I used it for another very different purpose.