7 Tips for Cold-Weather Solvent Welding

Solvent welding in a cold environment presents challenges that have to be counterbalanced. Why? Pipe and fittings take longer to soften in colder weather. The pipe is also more resistant to solvent attack, so softening it with an aggressive primer is important during cold weather.

By following certain cold-weather solvent welding instructions, and demonstrating patience, you can successfully solvent weld pipe joints in sub-zero temperatures (as low as -15°F).

We’re sharing seven tips to ensure successful solvent cemented pipe joints during the cold winter months.

1. Prefabricate as much of the piping system as possible in a warm environment.

We recommend assembling as much of the piping system as possible in a heated work environment. If you can control the temperature, it’ll make for better joints.

Any joints that must be made at the assembly work-site should be protected by some sort of temporary or portable shelter.

2. Store cement and primers in a warmer area.

Colder applications will require storing your pipe cement in a warmer environment (above 40°F). It’s important not to leave solvent cement outside in the cold for an extended period because it will take on a gel-like consistency. If the cement has gelled, we do not recommend using it. Solvent cement should remain fluid.

If you have bulk items on the jobsite, be sure to store them in a temperature-controlled area so it doesn’t come in contact with the cold.

Maybe you keep your cement and primers on your truck dashboard while you’re traveling between jobsites. In that case, if you’ve been out for a couple of hours, we recommend bringing them inside after your last service call. That way, the product can get acclimated to the warmer temperature and reach the right consistency for your next project.

3. Remove moisture from the ends of pipe and surfaces.

Before starting the solvent welding process, take time to clean off pipe ends and fittings to remove any dampness, residual water or ice. If moisture penetrates the cement, it will cause it to gel.

Of course, wet or damp conditions are sometimes unavoidable. In that case, we recommend using a solvent cement formulated to cure in damp conditions, like Oatey Rain-R-Shine, a fast-set cement designed for wet conditions.

4. Aggressively apply primer to fittings and pipe.

Particularly in colder applications, be sure to apply and aggressively work in primer. Primer must be used to create a solvent weld on PVC and CPVC pipes. Oatey Purple Primer is an NSF-listed primer for use on all schedules and classes of PVC and CPVC pipe and fittings.

To understand the importance of applying primer, it may be helpful to think of the fitting and the pipe as your skin. Your pores are coated and closed tightly; working the primer more aggressively onto the fitting and the pipe will ensure that you open up the pores. That way, you are preparing the pipe to accept the cement.

While applying primer to fittings and pipes, be sure to re-dip between each application. Once you have primed the pipe and the fitting, you have five minutes to apply cement and finish the connection. Waiting too long will negatively affect the creation of a good solvent weld.

5. Vigorously shake or stir cement before usage.

Before every use, we recommend shaking the can or stirring its contents before application. That’ll help blend in the components of the cement, making sure you get an even consistency throughout.

6. Allow a longer cure time before testing or using the system.

Cure time depends on several factors: pipe material, pipe size, ambient temperature and humidity. However, solvent cement will take longer to cure in colder temperatures. Allow enough time for the solvents to evaporate before testing the system or putting it in service.

In temperatures between 20°F to 40°F, the joint may take up to three days to fully cure for higher pressure applications. However, be sure to refer to the average joint cure times provided by the manufacturer for PVC, ABS and CPVC solvent cement. For temperatures below 20°F, we recommend contacting Oatey Technical Services for exact cure time information.

Do not attempt to speed up the cure time by applying direct heat to the joint because that could deteriorate joint strength or affect the integrity of the pipe.

However, you can create a temperature-controlled environment to accelerate the process. If you have a temporarily heated area, you may close off the openings of the dwelling to help speed the process while leaving your pipe ends open so that airflow can enter the system and help the solvents evaporate.

View our overview document for more information on all our cement offerings and their cure/set times.

7. Follow all ASTM standards and steps.

It’s important to follow all ASTM standards and steps in the solvent welding process. Be sure not to skip any when preparing the pipe — for example, choosing not to chamfer the pipe.

If you don’t chamfer the pipe or bevel the outside edge, the sharp edges can scrape the cement off the walls of the fitting, as the pipe is being inserted. This could potentially cause blockage or leak paths.

In colder temperatures, it is especially important not to skip these steps because the cold makes creating a solvent welded joint more challenging. To ensure you follow all ASTM standards and create a perfect solvent weld, avoid these five common solvent welding mistakes.

With our application tips for cold-weather solvent welding, you’re well on your way to creating long-lasting, leak-free connections this winter.

Author’s biography: Sean Comerford is a Technical Customer Service Specialist at Oatey Co. He is a third-generation tradesman with nearly 20 years of plumbing experience, including serving as the lead plumber for commercial/residential new construction, service and fire protection jobs. He holds a State of Ohio Fire Protection License for Sprinkler and Standpipe.