Micro CoGen.

Fuels/alternatives => Bio-Diesel => Topic started by: LowGear on January 30, 2010, 01:09:20 PM

Title: Pipe Fitting Sealant
Post by: LowGear on January 30, 2010, 01:09:20 PM
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
Title: Re: Pipe Fitting Sealant
Post by: BruceM on January 30, 2010, 01:18:52 PM
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.
Title: Re: Pipe Fitting Sealant
Post by: mobile_bob on January 30, 2010, 04:24:15 PM
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
Title: Re: Pipe Fitting Sealant
Post by: Crumpite on January 30, 2010, 05:10:39 PM
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...)
Title: Re: Pipe Fitting Sealant
Post by: mobile_bob on January 30, 2010, 05:35:59 PM
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
Title: Re: Pipe Fitting Sealant
Post by: TimSR2 on January 30, 2010, 08:23:20 PM
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
Title: Re: Pipe Fitting Sealant
Post by: veggie on January 30, 2010, 08:51:33 PM
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
Title: Re: Pipe Fitting Sealant
Post by: BruceM on January 31, 2010, 12:33:51 AM
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.
Title: Re: Pipe Fitting Sealant
Post by: bschwartz on January 31, 2010, 08:17:50 AM
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' !!!!
Title: Re: Pipe Fitting Sealant
Post by: Crumpite on January 31, 2010, 09:11:50 AM
Quote from: bschwartz on January 31, 2010, 08:17:50 AM
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
Title: Re: Pipe Fitting Sealant
Post by: BruceM on January 31, 2010, 10:47:35 AM
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.
Title: Re: Pipe Fitting Sealant
Post by: LowGear on February 08, 2010, 06:57:29 PM
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 (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.
Title: Re: Pipe Fitting Sealant
Post by: sailawayrb on February 08, 2010, 08:31:52 PM
http://www.summitracing.com/parts/LCT-37615
Title: Re: Pipe Fitting Sealant
Post by: LowGear on February 23, 2010, 10:39:34 AM
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
Title: Re: Pipe Fitting Sealant
Post by: NoSpark on February 28, 2010, 08:00:24 AM
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.
Title: Re: Pipe Fitting Sealant
Post by: Crofter on February 28, 2010, 08:53:11 AM
Get yourself a box of 20 Mule Team Borax! Besides being good for soaking the smelly out of diapers, it makes an excellent flux for brazing. I like to use up all my stubs and even inherited some bare bronze rod. Just heat the rod end close to melting and dip into the borax and it sucks on a load of flux. It will prevent a lot of porosity and it is dirt cheap compared to a five pound box of bronze rod.

Teflon tape plus dope is golden. Especially so on stainless that has a tendency to gall the threads.
Title: Re: Pipe Fitting Sealant
Post by: LowGear on February 28, 2010, 10:59:26 AM
GOSH!  That is pretty scary information.  I sure hope my brazen brazing doesn't go badl  I guess I can go back and reheat any bad joints.  This tank will have one of the $40 special pumps that we see all over biodiesel sites and I've decided to JB Weld the 3/4" by 1" sleeve into the pump.  And then go forward with the Gripp product.

Casey

PS:  I've heard about the double headed monster quite a few times.  The teflon tape plus dope approach.
Title: Re: Pipe Fitting Sealant
Post by: EBI-WPO on February 28, 2010, 02:23:09 PM
In the 80's while doing boiler installs, I would use the tape/dope trick to make up additional length on manifolds. This was easier than cutting a piece 1/8" or 1/4" shorter and threading it. Therein lies the rub. It will allow you to insert more taper with very little effort. This CAN result in the dreaded "Pop" sound of a creacked fitting (all materials, although easier with PVC). This method works very well but beware of deep insertion and cracking fittings. So.... just be careful out there.

Terry
Title: Re: Pipe Fitting Sealant
Post by: mobile_bob on February 28, 2010, 03:57:36 PM
well i happened upon a fresh stick of pipe sealant we use on everything
the one i referred to as looking like a kindergarden crayon or lumber crayon

it is marketed by ACE hardware and is #40968

cost a couple bucks iirc

supposed to be good for up to 2000psi, 350 degrees F, for metal pipe carrying
water, steam, air, ammonia, gasoline, natural gas, butane, propane, freon, and petroleum oils.
DO NOT USE ON OXYGEN SYSTEMS

we use it on everything that is pipe threaded, and it just works, there is enough in one stick to probably do hundreds of fittings
under common 1/2 pipe, few of course if you are doing large pipe.

i have used every other pipe dope and thread tape over the years and this stuff bar none is the best stuff for the job that i have
ever found.

two thumbs up there

bob g
Title: Re: Pipe Fitting Sealant
Post by: bschwartz on February 28, 2010, 06:46:46 PM
Wow! And It's cheap too...
http://www.acehardwareoutlet.com/(vssn5lampbpgnoj0eit0lm55)/ProductDetails.aspx?SKU=40968
Title: Re: Pipe Fitting Sealant
Post by: BruceM on March 01, 2010, 08:41:44 AM
Thanks Bob and Bshwartz.  I just ordered a package to try-  I've got some plumbing changes to make on my air plumbing in my "House of Lister".  Hopefully less mess and stink than the gray silicone gasket maker goop I've been using.