# Plumbers putty



## sirdavidofdiscus (Dec 8, 2006)

is plumbers putty fish safe? It would not be in the tank it's part of the filter so the fish can't pick at it.


----------



## fishEH (Sep 15, 2008)

Not sure about its safeness. What are you using it for? Could you use aquarium sealant instead?


----------



## sirdavidofdiscus (Dec 8, 2006)

Using it to seal a 6in cleanout at the base of my filter. I want to be able to unscrew the cap for maintience if I have to.


----------



## Mcdaphnia (Dec 16, 2003)

It is used on the waste side of plumbing so it does not have to be safe.


----------



## mightyevil (Oct 23, 2008)

Yeah, it is used in kitchen sinks, I just recently installed a sink and used the plumbers putty. IMO, if you use it on sinks, the chance of it being safe is high because all drains eventually end up in the ocean (well, most of them).


----------



## oscars4me (Feb 22, 2009)

I would not use plumbers putty. If you are sealing the threads on a clean out cap/plug use Teflon tape much safer and not as messy.


----------



## mightyevil (Oct 23, 2008)

+1 on teflon tape


----------



## PfunMo (Jul 30, 2009)

Plumber's putty seems to be one of those undying things that should have gone out with horseshoes. It has it's uses but they are not as often as used now. For sealing a cap that you will need to remove someday, I recommend silicone. It seals better and does not dry out like plumbers putty. Maybe that's why plumbers like to use it, They get to come back and replace it in a few years. :lol: Is it possible you have the wrong name for the product in mind? Sounds like for sealing threads on a cap you might mean "pipe joint compound" rather than plumber's putty. If it is the threads you want to seal, pipe compound will work fine but teflon tape is neat and clean as well as cheap in that it can be stored almost forever without drying out. I also would not hesitate to use silicone to seal the threads as it can be backed off with a wrench with no problem. :thumb:


----------



## Mcdaphnia (Dec 16, 2003)

Plumbers putty contains clay and or limestone, linseed oil, or fish oil or some other oil-like chemical. It stays pliable for a long time after installation, so if there is always water pressing on it, it will begin leaking. The released oils can coat the water surface in your tank interfering with the exchange of CO2 and oxygen.


----------



## sirdavidofdiscus (Dec 8, 2006)

Tried tape it still leaked though at a much slower rate. Now I'm waiting for the silicon to cure. Tomorrow afternoon I plan on testing it again.


----------



## PfunMo (Jul 30, 2009)

Good thinking on waiting for cure before the water. I had rental property for many years and did the maintenance. Silicone was the only way I could find to stop constant trouble with plastic traps under sinks. The plastic expands and contracts with temperature changes and they get bumped around a lot. I now automatically put silicone on before screwing them together. Makes them a bit funny when you remove as they tend to unscrew and then go back to the original position when you move your wrench. :-? Got to turn them far enough to break the seal and then you are good to go. You will find you don't need to screw the cap on nearly as tight with the silicone so in that way it may make it easier to remove. Good luck. :thumb:


----------



## fishEH (Sep 15, 2008)

Use this, RectorSeal.
http://www.rectorseal.com/index.php?site_id=1&product_id=212
It is potable water safe and is a sealant not just a lubricant like teflon tape and ordinary pipe dope.
Given your application, I would now advise against silicone. It may seal the first time but will be a bear to get it to seal again.


----------



## sirdavidofdiscus (Dec 8, 2006)

Well I used silicone. It hasn't leaked after 8hrs. of testing. Now I have the system all put together. Unfortunately I get so involved in a project like this I forgot to take any photos.
I'll try to describe it in another thread.


----------



## Acorn27 (Sep 1, 2009)

Just a heads up for everyone - Plumbers Putty can weaken certain types of plastic over time, especially ABS and similar. I think PVC is safe, but its just better to use siliocone or teflon tape like others mentioned.


----------



## PfunMo (Jul 30, 2009)

Maybe we need to get some definitions in here. Whene talking about plumber's putty, do we mean the stuff that comes in a container that you form to go between the sink and the drain or are you talking about the stuff that comes in a stick to be rubbed into the threads? They are two different things that I think may be getting confused here. The stick is really "pipe joint compound" not plumber's putty. I can't really think of using the real plumber's putty on threads although it could be.


----------



## FSM (Nov 11, 2009)

PVC cement (pipe joint compound) would work, why not just use that? There are a few different kinds, just use the stuff that says it is safe for potable water.


----------



## newfisher (Dec 20, 2008)

Pipe thread compound is a thread lubricant and sealer. It can be in a stick or paste that is applied to threads by brush of straight from a tube. Some pastes contain Teflon in various concentrations. Teflon tape is just that, a tape, that is used as a thread lubricant and sealer. Plumber's putty is totally different. It is a blend of stone dust and oils that resembles children's play doh that is meant to be "squished" between parts that are to be compressed together (usually with threaded fittings to pull them together), such as a drain tail piece to the a sink, where there is really no other easy way to obtain a water tight seal that can be undone and cleaned up to be redone again. It is typically rolled between the palms to warm it up to make it pliable and to form it into a "string" that can then be placed between the parts to be mated. Plumber's putty should not be used in threads.

PVC cement IS NOT a pipe thread compound. It is a glue composed of various solvents and dissolved PVC. The type of solvent used depends on manufacturer and purpose (PVC to PVC cement, PVC to ABS transition cement, etc.). PVC cement is intended to melt PVC, and when the solvent in it evaporates, will leave a bit of PVC behind, glueing whatever threads its put on together. I would not use PVC cement on any thread ... it will never come undone again and chances are, it will weld the threads together long before you have the chance to properly seat them.


----------



## FSM (Nov 11, 2009)

Didn't really read his post, oops. PVC cement is pretty much permanent.


----------



## PfunMo (Jul 30, 2009)

Only permanent until you cut it out and throw it away??


----------

