plumbing

[trble81]

All,

 

I've never worked with PVC plumbing with a tank before and I've got a question. I've got a piece of PVC, schedule 40, in a "joint". The joint says that it's 1 1/2" in diameter. I'm assuming that the piece in it is 1 1/4" (if it's a tight fit and is "chemically welded"). Now, I want to put a coupler on it, meaning I'll have to get a 1 1/2" coupler to work. Now here's my question, what are the steps to chemically weld the PVC? Is it you use the cleaner on the surfaces that will have contact, then the purple primer, then the cement?

 

Any advice will be great. Thanks very much!

[Origami]

Many primers already are cleaners. Prime then solvent weld ("glue"). You can get both at Lowe's or Home Depot. Someone in plumbing will be glad to help you.

[FishWife]

WELCOME to PVC! My husband, Scott, has fallen in love with the stuff. It's cheap, forgiving, and easy to replace, so buy a little extra and feel released to experiment.

 

When he works with PVC, he only uses purple primer and the proper cement (he's never used the cleaner and has fine results, though I think others would say the cleaner is important). Read the labels and be careful: there are two basic kinds of PVC: white PVC and CPVC (which is kind of off-white, when you come to notice it). These two types of pipes have slightly different guages, and are usually stocked side by each in the stores. When you're looking for parts there, or grabbing pipe, it's easy to mismatch, which is why I mention it. Also, the cements are type-specific, so make sure the cement you buy says "PVC" not "CPVC."

 

You don't want CPVC for fish tanks: it's engineered for high temps that you won't use.

 

When you look at joining parts, they are all engineered to work together. The nomenclature is that you use, for instance, a 1" pipe with a 1" joiner... elbow, coupler, female/male threaded or slip (no threads) etc. Eacy joiner has the size embedded somewhere on the part; the pipe has the size in black stamped on it.

 

Scott uses a hacksaw to cut pipes, and then he "dry fits" them to make sure his assembly is right. After cutting, you need to rub the raw edge with something like a small butter knife to get all the nibs off.

 

To join pipes permanently, put primer (purple) on BOTH pieces (inside one and outside on the other). Then, lightly cover BOTH pieces with cement. If working inside, do your wife a favor and put down some newspaper; it's virtually certain that you'll spill. (You must work quickly right after the cement is applied, so keep track of how you want any angles to be BEFORE you apply the cement.) Push the pipe and coupler straight into one another and then make a quarter-turn TWIST. Again, anticipate that twist when odd angles are anticipated.

 

Finally, you don't use cement of any kind on threaded joins. Rather, you use teflon tape. Ask more about that if you need to know.

 

HTH!

Edited February 9, 2008 by FishWife

[trble81]

Marcia and Tom,

 

Thanks very much for the info!