PVC Threaded Plumbing... Use Plumbers tape?

[Briko03]

Hi everyone, I am in the last stages of plumbing my tank and the remaining (non glued) connections are threaded. Since this is my first time using PVC I was wondering if people use Teflon / Plumbers tape on the threaded connections prior to installing them or is that more for just metal threaded connections?

 

[ca1ore]

Technically the Teflon tape is just for metal fittings and not recommended by the manufacturers for plastic. For the latter, you should use a non hardening thread sealant. Must say, however, that I do use the tape and with a little judicious application, it works fine. The risk you run is either over tightening the fittings or packing on too much tape. In either case, the result can be a cracked female fitting.

 

[Briko03]

Will this non hardening sealant create a permanent bond preventing removal in the future?

 

[redfishbluefish]

Technically the Teflon tape is just for metal fittings and not recommended by the manufacturers for plastic. For the latter, you should use a non hardening thread sealant. Must say, however, that I do use the tape and with a little judicious application, it works fine. The risk you run is either over tightening the fittings or packing on too much tape. In either case, the result can be a cracked female fitting.

+1 It's also important to wrap the tape in the right direction....so that threading the two pieces together don't cause it to bunch up. Not sure how to explain this. Holding the fitting in your left hand with the threaded portion facing left, wrap clockwise. Also, two or three times around where you pull the tape to break it off.....and no tape at the end of the threads.

 

[redfishbluefish]

Will this non hardening sealant create a permanent bond preventing removal in the future?

No....can still unscrew the pieces.

 

[trickedout900]

The thread sealant he is talking about will not harden and therefore can be removed, cleaned, reapplied and reconnected without issue.

 

[AZDesertRat]

There are products specifically designed for use with threaded PVC. All the PVC manufacturers including Spears and Lasco discourage teflon tape and have this posted on their websites, I have linked to it several times.
The product I use and recommend is the LaCo PVC thread lubricant stick.

Take a look at my sticky post on Bulkhead Installation, I go into detail on how to install threaded fittings and bulkheads.
https://www.reef2reef.com/forums/eq...iltration/34973-installing-bulkhead-tips.html

 

[PaulKreider]

I'm also working on finish my plumbing as we speak, the only thing i can add is with the non hardening sealant, make sure its PTFE.

 

[AZDesertRat]

PLASTO-JOINT STIK® | LA-CO

 

[Briko03]

There are products specifically designed for use with threaded PVC. All the PVC manufacturers including Spears and Lasco discourage teflon tape and have this posted on their websites, I have linked to it several times.
The product I use and recommend is the LaCo PVC thread lubricant stick.

Take a look at my sticky post on Bulkhead Installation, I go into detail on how to install threaded fittings and bulkheads.
https://www.reef2reef.com/forums/eq...iltration/34973-installing-bulkhead-tips.html

Ok, after reading this it appears as though I have made a mistake in my plumbing. Currently I have all my plumbing connected to my tank via a threaded union on the bulkhead of my tank which apparently is not a good thing. I have all my plumbing done using 1 1/4" pvc and connections. Should I rip all this out or just glue an adapter that connects the 1'' to the 1 1/4"

 

[AZDesertRat]

I believe what you are saying is you screwed a union to the non tapered threads on the outside of the bulkhead? If so this is not a good idea as it will leak. The outside threads on a bulkhead are more similar to bolt threads so you can screw the jamb or locking nut on to hold the bulkhead in place. Pipe threads are tapered so the more you screw a fitting (union) on, the tighter and more drip tight the fitting gets. While a 1.25" union might catch a starting thread or two on the bulkhead it will not seal well since you are only sealing at one tiny point and not the entire length of penetration.

Personally I would buy a 1" thread x thread bulkhead and screw a 1" threaded PVC nipple or a 1"x 1.25" male adapter so you can connect to your existing 1.25" PVC. Make sure you spend the necessary time to properly install the bulkhead and to clean out the threads and sealing surfaces of the bulkhead so you only have to do this once without fear of leaks. If the bulkhead is supporting the weight of the plumbing try to build some sort of additional support bracket to take the weight off of the bulkhead so it seals well.

 

[Hellsinki]

I've always used Teflon tape with pcv tapered thread fittings and have never had any ill effects or leaks.

 

[mfinn]

PLASTO-JOINT STIK® | LA-CO

Is this the sealant you recommend?


http://www.amazon.com/LA-CO-Plasto-Joint-Plastic-Sealant-Temperature/dp/B004MYFP8C

 

[choff]

This is a great do/don't link on threaded pvc.

http://www.lascofittings.com/threads

 

[cracker]

Iv'e always used teflon tape never a problem here either.

 

[Robert_ellis]

Only problem with the three sealant is the chemicals used in it. Some of the chemicals may be toxic to a tank. Teflon tape wrapped 2-3 times is fine. I own a landscape business and when not using tape I have more leaks then when I don't use it. I know they say not to BUT if the fitting has been damaged in any way you are prone to leaks. Just use Teflon, hand tighten and then use channel locks to get another 1/4 to half turn on it. You'll be fine.

 

[AZDesertRat]

The LaCo sticks are fine for reef use, there are no problems and lots of advantages.
http://www.laco.com/assets/1/31/plasto_joint_stik.pdf


Not only does Lasco have an article on not using teflon tape, so does Spears:
http://www.spears.com/tech_updates/TECH-2-No.111_web.pdf

 

[Big Dog]

I've always used Teflon tape with pcv tapered thread fittings and have never had any ill effects or leaks.

Big 10-4, I only use tape on threaded fittings ..............

 

[d2mini]

Grit free thread sealant is the way to go.
Just go easy on it, too much and it can get kinda messy. The stuff doesn't dry.

 

[AZDesertRat]

We have all used teflon tape at one time or another but that doesn't make it right. Follow the PVC manufacturers recommendations just as you would anything else, its recommended for a reason.

Personally I can say my inground swimming pool pumps and fittings were installed in 1983 using the LaCo Plasto Joint stick lubricant and to this day the joints are drip free and still pliable, and that is in the Phoenix AZ sun all summer long. There is a reason it is recommended.