Threaded fittings issue

ChrisJ

I want some thoughts on this from the experts.

I've gotten pretty good at working with threaded fittings as long as they're metal and decent threads.

But I'm having issues with plastic npt fittings on our pool for the hoses.

They're cheap and even have seams and I just can't get them to seal yet just using blue monster tape. They also almost bottom out by hand..... They pretty much suck imo.

I'm stuck between trying more tape ... Tape + megaloc and just going to rtv.

My fear is cracking something at this point and I don't know if rtv will come apart?

Thoughts? In using hoses at least for now so decent PVC fittings are out for the time being.

Tinman

I use teflon dope on top of teflon high density tape. Tighten just beyond hand tight. No problems.

JUGHNE

I have had the female adaptors crack sometimes and a major PITA. If ascetics are not that important, I have put a SS hose clamp on the FPT portion for reinforcement.

KC_Jones

@ChrisJ they make a special sealant/dope for PVC threaded fittings. We had issues for years at work, once we switched it all went away.

https://www.spearsmfg.com/prod_brochures/BLU-2-0200_1010.pdf

EzzyT

They make pvc fittings with stainless reinforcing around the hub of the glue solvent part of the fitting.

hot_rod

I agree with KC. use a thread sealant specifically for PVC threads. You should not need teflon tape either.

ChrisJ

These aren't PVC they're some other cheap feeling plastic

Tape + dope seems to have worked.

MikeL_2

I agree with a stainless steel clamp to reinforce plastic female adapters. We use ball or string wicking tightly wound clockwise on to plastic male threads before wrapping with several layers of quality teflon tape; it works every time......

clammy

Almost all the pool guysi know use sch 80 fitting and adapters ,especially on male adapters and as for tee they usually use a full size tee and glue in female fitting adp the fitting tends to not split that way .as for loose threads a few wraps w tape and a dab of some pipe dope and it’s usually good .if this is for a small seasonally pool I would look to a pool supply those smaller pool skimmers and such are usually a smaller dimension then heavy residential or commercial pool heater filtration piping .peace and goog luck clammy

Intplm.

@ChrisJ I have used regular teflon tape with and without the pipe dope combination. Try either way that works for you.
Six wraps around with the regular teflon tape. Tighten as much as you can by hand then use water pump pliers to snug it up. Have installed thousands of joints with little problem.
Good luck

Hap_Hazzard

Sorry to revive an old thread, but this is a hill I've conquered. I've done all my own pool plumbing for 20 years.

For threaded plastic fittings, I always use the thick, gray PTFE tape they sell at Home Depot. It's called FASTape, because three wraps of this is like 10 of the white stuff. Use those rubber strap wrenches for tightening and don't overdo it.

If it leaks, take it apart and inspect it. It's usually because of excess molding flash. That's the big difference between plastic and metal: metal threads are machined, so the fix is, obviously, take a CLEAN tap or die and clean up the threads. I have a 1½" tap and die that I use exclusively for plastic so they're not all greasy and dirty from cutting pipe. I used to use an X-Acto knife for cleaning up plastic threads, but life is too short for that.

Never, ever use pipe joint compound on plastic pipe! (It may mention that on the label.)

If you have assemblies that you use from one season to the next, it's worth taking the time to paint them. This includes the flexible pipe too. PVC is very cheap and popular for outdoor plumbing, but most of it isn't UV resistant, so it gets destroyed by being out in the sun. ABS is more likely to be UV-resistant, but most of the fittings you buy are PVC.

KC_Jones

Hap_Hazzard said:

Never, ever use pipe joint compound on plastic pipe! (It may mention that on the label.)

This isn't entirely true. The PVC manufacturers make a dope specifically for use with their pipe. Our company has found it's the only thing that will work with the plastic. Also we never need to clean up the threads with the proper compound.

https://www.spearsmfg.com/prod_brochures/BLU-2-0200_1010.pdf

Ironman

My good friend who's the manager for a large pool company told me years ago that they use silicon caulk on the threads and never have any leaks. FWIW.

Hap_Hazzard

KC_Jones said:

This isn't entirely true. The PVC manufacturers make a dope specifically for use with their pipe. Our company has found it's the only thing that will work with the plastic.

I'm not familiar with that product, but the problem with any type of pipe joint compound on plastic threads, especially in the hands of DIYers, is that it acts as a lubricant and makes them overtighten the fittings to the point where they start to leak. It can also get into the pool water and/or filter medium, interact with pool chemicals and make a mess.

Note that Spears doesn't say anything about their product being intended for swimming pools. All they say is, "User shall determine the suitability of the product for its intended use and all risk and liability in connection therein. Manufacturer is not responsible for consequential damages."

KC_Jones said:

Also we never need to clean up the threads with the proper compound.

And I never need to use compound if I clean up the threads.

But, seriously, I rarely need to resort to that. The gray PTFE tape is usually enough.

Hap_Hazzard

Ironman said:

My good friend who's the manager for a large pool company told me years ago that they use silicon caulk on the threads and never have any leaks. FWIW.

At least silicone RTV sealers are safe for pools once they're cured, but I'd never use it on threaded pipe. It would either come apart unexpectedly or make the joint hard to take apart when you want to.

Thick gray PTFE tape FTW.

EBEBRATT-Ed

Lots of pipe dope is approved for plastic Rectorseal True Blue is one but teflon usually does the job

I have had cheap fittings bottom out and have removed them and cut off a thread or two