PVC Plumbing How-To

I have been asked about plumbing several times so here is a long over due how-to for pvc plumbing. There are several variations and myths in regard to plumbing, but if you are new to plumbing and want to avoid leaks just follow these steps.

First I would like to address two myths of plumbing. The first myth is that you do not need cleaner or primer on new pipe. Both cleaner and primer cut the oil from the extrusion process and most importantly, they also etch the surface to prepare the plastic for glue. I have had to make many repairs to my work and to that of other plumbers. When taking apart joints, it is easy to tell when the other plumber did not use cleaner or primer. The joints can be peeled apart. Joints that were prepared with cleaner or primer can not be peeled apart; they become chemically fused or welded. The second myth is popular with old timers. It is said that sanding the joints will replace the cleaner or primer. Again this does not hold. You will get a stronger joint because now you are adding a mechanical bond, but the plastic still does not weld like when you use cleaner or primer. Also, by sanding the pipe, you are changing the clearance of the pipe and fitting.

The only substitute for cleaner is primer. The only substitute for primer is cleaner. Both contain MEK (Methyl Ethyl Keytone) and Acytone (and other mean chemicals). The main difference between the two is that primer contains purple dye. That way you can check your work and it also offers a security blanket. There is another myth that the purple dye is the primer and plays an actual part in the chemical bond. This has been passed from plumber to apprentice for decades and is usefull in getting them to use the product. It really came about for code inspection. Some municipalities require the purple dye because there are so many plumbers that still insist that new pipe does not need cleaning or priming. Cleaner is still primer but it does not have any dye. As soon as the cleaner dries it is hard to tell if it has been used. That is why the inspectors need the dye.

That said, here is a picture of a fitting that I cleaned with a dry brush. Where the dye is missing, there will be a good chance of a leak. If you do not have experience with plumbing, spend the extra dollar or two for the purple primer so that you can check your work.

Here is that picture...hopefully

In that second picture, I was in the process of priming the second piece. It is not necessary to hold both pieces but it really makes it convienent when you glue them. Holding multiple parts also makes the job go faster.

In this next one, I had primed them and I think I already glued them or was about to. It is very important to glue both parts, not just one. Two cents worth of more glue on the job can make the difference in leaks or no leaks. Never put together dry or partially glued joints. Always assemble the parts before the glue starts to dry. If in doubt, you can always add more glue.

This next picture is a principal that should be used for any valves or unions. Any time a component has internal workings or seals that could be fouled due to the glue, make sure you plan ahead. The idea is to do all cleaning and gluing in a vertical position with the component in the upward position.

In that last pic, both parts were primed. In this one they have been glued and positioned for drying.

After sufficient time (five minutes is good), the part can be flipped and the other side glued. The same step must be taken to keep the glue out of the component; a check valve in this case. Notice I have started a union using this same method.