Solvent welding is one of the best ways to create strong, leak-proof connections in a water system. It works by chemically bonding pipes and fittings into a single, solid piece. But because it’s a chemical process, factors like heat and humidity impact the process, and adjustments to installation technique are critical. If you’ve ever tried to solvent-weld a PVC joint on a hot day and felt like you were racing the clock, you’re not imagining it—heat makes everything set faster, which can make the job trickier.
But don’t sweat it (well, at least not about the joints). Follow these five tips to ensure solid, long-lasting joints during the summer months.
1. Keep It Cool (As Much as Possible)
Store solvent cements and primers in a cool, shaded area below 100°F before use.
If possible, keep pipes and fittings (or at least their ends) in the shade before solvent welding.
Wipe pipe surfaces with a damp rag to cool them down—but make sure they’re completely dry before applying solvent cement.
Try to schedule solvent welding for the cooler morning hours when temperatures are lower.
2. Work Fast, But Smart
Solvent cement evaporates faster in the heat, meaning you have less time to assemble joints before they dry out.
Always make sure both surfaces are still wet with solvent cement when putting them together.
For larger diameter pipe, enlist an extra set of hands (or two) to speed up assembly.
3. Choose the Right Products
High-viscosity (thicker) solvent cements provide more working time in hot weather. Try using Weld-On 719 (or 729 for CPVC) for a slower set time.
Don’t skip primer! Primer softens the materials evenly and buys a little extra working time – ensuring a strong bond.
Don’t forget to vigorously shake or stir your solvent cement and primer before use to ensure proper consistency.
4. Be Mindful of Expansion & Contraction
Heat causes piping to expand and then contract as temperatures drop, creating stress on joints. Follow pipe manufacturer guidelines on expansion and contraction allowances.
Try to make final, anchored connections during the cooler hours of the day to minimize shifting as temperatures fluctuate.
5. Avoid Puddles and Excess Cement
Inside a joint, excessive solvent cement can attack hot pipe surfaces too aggressively, weakening the material. Solvent cement and primer should be applied evenly.
Avoid puddling solvent cement inside fittings, and wipe off any excess outside the joint.
Final Thoughts
Hot weather can make solvent welding tricky, but with the right techniques, you can still achieve strong, leak-free joints. Just as cold temperatures slow things down, heat speeds them up—so knowing how to adjust your approach is key.
Want to level up your skills? We offer trainings to help contractors and counter staff get qualified in solvent cement welding. Contact our team to schedule a product training event.
Give us a call!
(253) 845-4050
office@cimcopnw.com