Joining PVC conduit and fittings is one of the easiest conduit connections you can make. A properly done cemented joint is permanent and both airtight and watertight, and it takes less than a minute. Be sure to deburr the conduit if you cut it before gluing. Also, make sure you have the right cement for the conduit you are using.
The stuff you use as conduit glue is properly called PVC solvent cement.
It comes in a small metal can with a twist-off cap. Attached to the cap is an applicator that looks like a pom-pom on the end of a stiff wire. A small can of cement is suitable for conduit up to about 3" in diameter. For 3" or larger, it's better to use a large can, which has a larger applicator.
Is Primer Necessary?
When gluing PVC plumbing pipe, plumbers typically use a primer before applying the PVC cement. Primer cleans and dulls the surface of the pipe to promote bonding. It's fine to use primer with PVC conduit, but many electricians skip this step unless it is required or recommended by the conduit manufacturer or by the local building authority. If you want to use primer, it can't hurt.
How to Cement PVC Conduit
- Deburr the cut end of the conduit, using a utility knife or emery cloth.
- Wipe the outside of the conduit and inside of the fitting with a rag to be sure they are clean.
- Apply a thin, even coating of PVC primer (if using) to the outside of the conduit and inside of the fitting, coating the entire area that will make contact. Apply a coating of PVC cement to the same areas.
- Insert the conduit into the fitting and push until the conduit bottoms out in the fitting socket. Keep pushing the pieces together and give the fitting or conduit a 1/4-turn twist, then hold the pieces together for 30 seconds (or as recommended by the cement manufacturer).
- Do not stress the joint for 30 minutes, or as recommended.
Tips for Gluing PVC Conduit
If the conduit or fitting is already fixed (can't be moved) and the parts must have a precise orientation after they are glued, use the plumber's trick of dry-fitting the parts and marking them with a pen. Once the pieces are just as you want them, draw a straight line that runs across both pieces, using a Sharpie. Pull the pieces apart, apply the cement, then fit them together. After making your 1/4-turn, align the pieces so the marks form a single, straight line again.