How to Use Pipe Joint Compound
Step 1 - Cut the PVC Pipe Properly
Before you use the pipe joint compound to connect a piece of PVC pipe to a connection fitting, you need to ensure that you cut the PVC pipe properly. When cutting PVC pipe, use a sharp hacksaw and try to cut the pipe as evenly as possible. You might find it useful to use C-clamps to hold the pipe to a sturdy table or even a concrete block when cutting the pipe. If you don't have a clamp available, try to hold the pipe as steady as possible as you cut the pipe with the hacksaw.
Step 2 - Clean Up the Edges of the PVC Pipe
After you've cut the PVC pipe, take a piece of sandpaper and lightly scuff it up and sand the edges of the pipe. Whenever you cut PVC pipe, there will always be some pieces of the plastic that stick out and appear like small shards that must be sanded away. This will also make it easier to insert the PVC pipe into the connection fitting.
Step 3 - Apply PVC Primer to Pipes and Fittings
Now that you have prepared the pipe, you can use the PVC primer. PVC primer helps to create a better bond between the plastic PVC pipe and the adhesive in the pipe joint compound. To apply the primer, simply take the lid off the can of primer. Attached to the bottom of the lid will be a dobber that you will use to spread the purple-colored liquid on the outside of the pipe in on the inside of the connection fitting.
Step 4 - Apply Pipe Joint Compound to Pipes and Fittings
Applying pipe joint compound to PVC pipe is almost the same as applying the primer. Just open the can and use the included dobber to spread the pipe joint compound on the outside of the PVC pipe. Then, use the dobber to apply the compound to the inside of the connection fitting. When applying the compound, apply enough adhesive to hold the two pieces together, but do not "gob" or use too much of the compound as it may make it hard to properly seat the piece of pipe into the connection fitting.
Step 5 - Attach the Pipe to the Fitting
Finally, you can insert the pipe into the connection fitting. To do this, you will need to use a twisting motion while applying pressure to both the pipe and connection fitting. As you twist, the PVC pipe will work its way into the fitting. Continue pushing the PVC pipe until it has seated on the lip inside the connection fitting. When you can no longer push the pipe inside the fitting, the pipe has been properly seated.