To Teflon or not to Teflon, that is the question ...

[SeaMasterZ@aol.com]

I have a pair of those Wal Mart tanks, the attwood jobbers (and found a big plastic tank I had gotten years and years ago, pics when I get a chance to drag it out) and my question is this ... it has plastic fitting, and I got a brass fitting to hook the fuel line into her ... now usually, I use teflon tape, but I wonder if that fitting is self sealing since its going into plastic? I know, stupid question but I dont want to take ANY chances on doin something stupid, lol

 

[OBJ]

Re: To Teflon or not to Teflon, that is the question ...

Me again Ray.....<br /><br />It don't never hurt to use a wrap of tape especially on a used tank. Problem with Teflon, after a while the stuff gets sticky from the gas. I usually use a gasket sealing compound the is impervious to gas.....big word there. Anyway, put something on the threads before hooking into tank.<br /><br />Me

 

[JB]

Re: To Teflon or not to Teflon, that is the question ...

Moving to General Outboard

 

[Bob Kimber]

Re: To Teflon or not to Teflon, that is the question ...

Hi CastawayRay,<br /><br />Having previously been in the plumbing trade for 33 years, I have to advise you not to use the standard teflon (treadseal) tape as it is NOT suitable for use with petroleum based materials such as propane gas, natural gas or liquids such as petrol and other refined spirits. As OutboardJim has noted it will start to break down and become sticky before eventually dissolving, you should use an approved (gas or liquid) thread sealing compound or if you talk to your local hardware store you can buy a type of treadseal tape that is approved for gas fittings. In Australia this tape is a yellow colour and is specifically approved for gas use and is suitable for use on fuel fittings and connectors, it generally is only slightly more expensive than standard teflon tape.<br /><br />Accident investigations in Australia into some gas and fuel explosions have consistently found the cause was linked to the use of the incorrect tape and it is now part of the regulations outlawing the use of incorrect teflon treadseal tape on anything but water supply installations.<br /><br />Bob

 

[grandx]

Re: To Teflon or not to Teflon, that is the question ...

I must respectfully disagree with the above, I'm in the pipe business for the oil field particularly in relation to chemical resistance. There are few sealants (if any) that are more resistant to chemicals than teflon (PTFE). Teflon tape is impervious to gasoline, and most everything else. If you experience teflon tape degrading in contact with gasoline, you likely have some sealant that is not 100% PTFE. Don't just take my word for it... here's a copy of someone's chemical resistant chart... note the PTFE is E-excellent with gasoline.<br /><br />Chemical PTFE SS PE#1 PE#2 PP PVC <br />Gasoline E E F G E G <br />Glycerine E E E E E E <br /><br />Search for yourself, and please post if you find where teflon is not acceptable with gasoline.

 

[SeaMasterZ@aol.com]

Re: To Teflon or not to Teflon, that is the question ...

grandx, I think the main problem is a matter of corporate bean counters using only enough PTFE to satisfy the minimal content requirements ... Jim and Bob are likely right, as I am sure you are too ... the yellow tape is likely 100% PTFE, whereas the white stuff is a blend, be it proprietary or generic, that is insufficient for gasoline/petrochemical useage<br /><br />eh ... Ill browse the aisles at pep boys till I find something that says gasoline approved, lol, I love this forum, I was uncertain if what is sold as teflon tape was good for gas, and now I know it is ... as long as its PURE PTFE.<br /><br />did you know that the world record for lowest drag coeeficient (I think thats how they measured it anyway) is good ol PTFE? its described as wet ice on wet ice ... about as slippery as it gets<br /><br />Thanks guys!!! no booms here, lol

 

[BAINOR]

Re: To Teflon or not to Teflon, that is the question ...

I'd have to agree with OutboardJim about using a sealer impervious to gas & oil. Just also make sure it is approved for use on the type of plastic you are using it on. (Wouldn't want the sealer to interact with the plastic and weaken it)<br /><br />The other thing is that when using teflon tape on tapered threads; if the female fitting, the one being screwed into, is plastic, teflon tape can stress that plastic fitting possibly to the point of breaking the fitting, where a liquid type sealer will flow out the threads and not stress except from the mechanical taper of the threads.<br /><br />Boating Bob, I was in the plbg. field for 28 years.

 

[SeaMasterZ@aol.com]

Re: To Teflon or not to Teflon, that is the question ...

I usually use one and a half wraps, just enough to get some teflon in there ... that shouldnt be too thick

 

[Bob Kimber]

Re: To Teflon or not to Teflon, that is the question ...

Hi CastawayRay,<br /><br />Following the post from grandx I think it may be necessary to clarify the Teflon tape issue further. Grandx is technically correct when he said teflon is suitable for use on petroleum based products, but I think he missed the main point of my post, which is that all teflon tape (PFTE) “is not created equal”, he actually mentioned this in his post when he said “if tape degrades it is not 100% teflon”<br /><br />During my 33 year association with the plumbing trade I was also a Workplace Health & Safety Officer and the Quality Assurance Representative for my employer (a Federal Government Dept) for a considerable number of years, in addition to this I am also a licensed gas fitter & installer. The safety officer position required me to be involved in accident investigation and research in the construction and manufacturing industries.<br /><br />As stated in my previous post, explosions and fires have been directly linked to the use of incorrect Teflon tape. An extract from the regulations for materials use in the industry states “commercial PTFE (teflon) tapes are not suitable or approved for gas or petroleum based derivatives service”, it goes on further to state an approved teflon theadseal tape (Dupont trademark) must be used in this situation.<br /><br />My main concern was that the majority of so called “teflon tape” available from general hardware and other suppliers fall into the unsuitable category, this is because the marketing gurus that control the industry state the product is teflon even if it only contains a small amount of teflon blended with some other type of material. Sorry about the long winded post but I feel it is an important safety requirement to be aware of the true facts. you would still have to be careful when using a sealant like tape on plastic fittings.<br /><br />Bob

 

[Bob Kimber]

Re: To Teflon or not to Teflon, that is the question ...

Hi Ray,<br />I hadn't read your replies before I sent this post.<br /><br />Hi Bainor,<br />Sorry I didn't see your post prior to posting my last reply (cut & pasted a word document), you are totally correct in advising caution on damaging the plastic thread, I only touched briefly on that point in my previous reply. It could be a "catch 22" situation threadseal could stress the plastic and liquid or paste sealant could be displaced enough not to adequately seal the thread.<br /><br />regards Bob