Sealing fuel line joints

[Jens]

I am about to start on reassembling the fuel system on Thumper. I will have a large number of joints AFTER the fuel filter. I have previously used teflon tape but there is always a risk of getting a chunk into the system and I would rather not take this risk in this particular installation due to the many joints involved. What is the normally suggested/approved method of sealing tapered pipe thread joints in these situations?

... and for those of you who want to know just exactly why I have so many joints, the filters will be by the fuel tanks, then there will be shutoffs', a T to join the veg oil and dino feed, a pump,another T at the engine, a shutoff for each cylinder, a whole slew of hose barbs, nipples and other hardware. There are just too many possibilities to take the risk even though I will run fuel through for washing the lines prior to startup.

[mobile_bob]

the larger "real" hardware stores sell a stick pipe sealant that looks like a lumber crayon, the stuff is offwhite in color
and is by far the best sealant money can buy, and that makes it about 2 bucks and change for a stick.

one stick will do ever sealing job you have, for the rest of your life unless you are a plumber by trade.\

it is good for oil, gas, water, and hydraulic pressures up to about 3kpsi, although i have used it for systems well over
4kpsi.

no muss no fuss, it just works, and is handy as a pocket on a shirt

bob g

[mobile_bob]

it is marketed by ACE hardware and is #40968

it is used much like you would scrape a crayon across the male threads, and you don't have to cover all the way around

i have not found it to work inside and cause a problem

we use it alot,

as for rtv i quit using it because it is worthless on air fittings, even worse on h/p hydraulics

bob g

[Ronmar]

There is another compound I have found called blue seal.  It is a paste applied with the in container brush or your fingertip.  Good/safe for just about any type joint from propane to drinking water and all fuel/oil combinations.  It is available at most hardware stores, and I know do-it-best stocks it.

As for material inside, put the material on the male threads, dont put any on the first two end threads and don't gob it on. just lightly fill the grooves and wipe off any excess.  In the case of the blueseal, running your finger around the threads will wipe off a little extra and  bring the level below the top of the threads.  As you screw it in, a little will be deposited at the end of the female threads as it is scraped out of the grooves.  this leaves a neat little fillet around the joint.  I have never seen this stuff migrate to the tip of the threads...  it is thick, and appears to have a slightly fiberous texture.  

Here is the stuff on their website.

http://www.doitbest.com/Pipe+joint+tape+and+compound-Wm+H+Harvey+Co-model-025301-doitbest-sku-437138.dib

[Randybee1]

it is marketed by ACE hardware and is #40968


bob g

Bob.. I just entered 40968 into Ace Hardware's search engine and it comes up blank. Perhaps you have another number?
Randy B

[mobile_bob]

the damn stuff is hard to get to come up on ace hardwares site, and i have no idea why, but here it is

https://www.acegeneralstore.com/inet/storefront/store.php?mode=showproductdetail&product=-1&link_id=-1&link_itemcode=40968&category=&department=04&class=449

bob g

[Randybee1]

Got it!, Thanks.. Randy B