Pipe Fitting Sealant

[LowGear]

Are there many things more frustrating than getting your art project put together and have the fittings leak.  In my case, only on the pump - both inny and outie.  What's the kick ass stuff to use besides a little more elbow grease?

Casey

[BruceM]

Assuming you've already used regular pipe dope, not just teflon tape (which isn't reliable over 1/2" pipe size in my experience), I'd suggest 100% silicone caulk as pipe dope.  Clean the fittings well first, with some alcohol or acetone. Let it dry for at least 24 hrs. Make sure you put just a little on the female fitting, too much will make an obstructive blob on the inside. I've used this often, and it works well.

[mobile_bob]

in my business, and i put together lots of hyd, fuel, water and air fittings
the best stuff i can find is the stick that looks like a kindergarten crayon or a lumber crayon
it comes in a tear away cardboard tube and is about the same consistency of a greasy crayon for lack
of a better way of describing it.

we have horrible problems with silicone, air pressure will blow it out of the threads as will fuel and oil
and most certainly hydraulic oil under pressure.

might work for some folks it just don't work worth squat for us?

maybe we aren't holding our mouths right

bob g

[Crumpite]

Folks,

Yes, I've had troubles with silicone sealant too.
I've yet to find a universal pipe thread sealant but I think that Locktite PST is the closest I've found.

For hydraulic work I use the Loctite stuff meant for it, I've only had one joint failure with it.

I like the anaerobic sealants best, but there seems to be a whole books worth of preferences based on experience.
The best pipe fitters I knew switched to the PST stuff when it came out, for what it's worth...

Daryl (currently in sunny Florida...)

[mobile_bob]

i like the loctite pst stuff, but that which is sold in the chapstick tube runs out too quickly
and that which is in the plastic can with a brush is too runny for my likes. but both work
exceptionally well.

we just use the solid crayon stick stuff, because it is easy to use, never runs out it seems
and is much lower cost than the loctite stuff.

and it doesn't get dirt in it or spill in our service trucks

bob g

[TimSR2]

Grey teflon pipe dope from the mechanical wholesaler. Just ask them what the sprinkler fitters and gasfitters use and they will fix you up. You will never look back.

Tim

[veggie]

Hi Casey,

I'm using  the same circ pump as you on the biodiesel reactor.
I use teflon tape on all my threaded fittings. No problems so far.
For biodiesel and veggie oil, it's recommended to use the teflon tape in the YELLOW enclosure which is meant for gas fittings.
It's a bit thicker and stands up to the oil better.

good luck,
veggie

[BruceM]

For my air system (150 psi)work, I use the gray silicone gasket goop.  Never had a failure or leak, even on reused fittings. You can still take them apart. You don't have to be fussy about clean up with the gray stuff, but I don't trust it for potable water.

I'd like to know more about the "crayon" or stick type thread sealant products- they sound handy.  Got a product and brand name so I can google some anyone?  I know it's not something I'm going to find in my small town.

[bschwartz]

I tried the teflon pipe dope, and the veg oil disolved it.  Teflon worked OK in some places, but where I had hot oil and pressure, I finally threw in the towel and used epoxy!!!  They ain't never comin' apart or leakin' !!!!

[Crumpite]

I tried the teflon pipe dope, and the veg oil disolved it.  Teflon worked OK in some places, but where I had hot oil and pressure, I finally threw in the towel and used epoxy!!!  They ain't never comin' apart or leakin' !!!!

That's exactly my experience !
I went through three kinds of pipe dope, and they all dissolved sooner or later.

Permatex dopes dissolve right off, the paste teflon stuff takes a little longer.
Some sort of professional blue stuff I got from the local hardware works for everything except for hot WVO.

PST does it all, but it's sure expensive !

Daryl

[BruceM]

I found the Loctite PST stick- looks like something I'll try, if the smell doesn't knock me for a loop.

Silicone should do the trick and not be affected by heat or vege oil.  The Permatex gray silicone gasket material is sold at Napa.

[LowGear]

Thanks for the great feedback.

I did post the question in a few other places and a very interesting piece of information came in this link:

http://bayareabiodieselsupply.com/storefront/index.php?act=viewProd&productId=84

This link told me two things.  The threads on these pumps suck and or leak.  I used yellow tube style pipe dope which I have never had leak on me but some of you go through more threads in a week than I have in my life.  So the gosh darn leaks from both pump ports (you know that was just the phrase I uttered.) really threw me until I saw these units.  "O" rings dela-cream is what I'd call them.

The shortened version:  I'm going with the "grrip" product because the small print says it'll do everything.  Now I prefer a tube because it doesn't leak or spill very much when I'm in the heat of battle and I simply couldn't find the crayola stuff anywhere in West Hawaii, The Big Island.  (Tourist crapp, back up your truck.  Shop things, you should be so lucky.)  This 8 oz bottle was about $11 at Furguson (SP?) which are all over the western US, maybe bigger for all I know but this was the kick butt stuff in their warehouse.

Should this fail and I recover from the breakdown (it's an absolute "sea biscut" to get apart) I will JB Weld the 3/4" bushings after cleaning everything vigorously with acetone into the pump ports.  You're mumbling "Why not JB Weld the bastards Now?"  Because, as a man, I don't take the easy way out!!!

I'll update you in a week or so.  Thanks again,

Casey

PS:  Should any of you have used this marvelous stuff and found it to be crapp please don't be bashful.

[sailawayrb]

http://www.summitracing.com/parts/LCT-37615

[LowGear]

I'm trying a new concept.  Brazing.  I'll let you know how it works in a month or two.  Sorry about the focus.

Casey

[NoSpark]

Whats discouraging, is when you braze fittings and they start to leak after awhile. I brazed together a couple of coolant fittings for the 'oid and evidently there were a couple of porous spots filled with flux that later dissolved. That will teach me not to use old brazing rods with the flux half flaked off. 

As far as thread sealing goes, I watched my father-in-law(retired pipe fitter, miilwright) put both thread tape and dope on fittings for years and wondered why until I had to get a well pump fitting to stop leaking, now I do the it on all my fittings. I use PST also.