Can You Spray WD40 On A Water Shut-Off Valve?

Perhaps you have a DIY plumbing project lined up that requires the water off. You have everything ready – all of your tools are together, you have the necessary replacement parts, and you’ve gathered the willpower to complete the project – only to find out that the water shut-off valve won’t budge. 

Considering shutting off the water is the very first step of most plumbing projects, yours just came to a screeching halt. So, now what? The valve won’t budge, and your motivation to do this project is rapidly depleting. Well, lucky for you, we put together a quick guide to get your project back up and moving in no time. 

What Causes The Water Shut-Off Valve To Stick?

Water shut-off valves are a critical part of your home’s plumbing system. They’re usually underneath sinks, on toilets, with the main shut-off valve located in the garage, basement, or outside. In emergency situations, like when a pipe freezes and bursts, the shut-off valve is what stops the flow of water threatening to flood your home.

However, most folks don’t regularly shut off the water in their home, especially the main shut-off valve. While a few years without being used shouldn’t cause the valve to freeze (unless it’s corroded), a few decades will do the trick. Stuck shut-off valves are a common problem in homes with older plumbing.

Eastman 10809LF Multi-Turn Angle Stop Valve with Brass Stem 1/2 inch FIP x 3/8 inch OD Comp, Chrome

Generally, corrosion or mineral scale is the cause of stuck plumbing shut-off valves. Over the years, mineral scale builds up inside the pipes and connections, causing issues like a stuck valve. 

Corrosion may occur on the outside of the valve, especially if there is a leak or it’s an outside valve with exposure to the elements. The process happens slowly over time, gradually fixing the valve in place until it eventually becomes unmovable. 

How Do You Lubricate A Shut-Off Valve?

When dealing with stuck shut-off valves, it’s imperative that you don’t try to force the valve open or shut. This can cause the valve or pipe to break, which creates an additional project for you to deal with. If the pipe cracks or the valve snaps, you might have to call in a plumber for repairs, as this can be quite the problem. 

So, we recommend taking it slow unless you want to pay a hefty plumbing bill. Instead of using brute force to open the valve, exercise a bit of patience and let a penetrating oil do the grunt work for you. Generally, any penetrating oil that is marked as safe for plumbing will do the trick.

 Using penetrating oil on a stuck plumbing valve is straightforward. Simply spray the oil on the valve, then allow it to sit for a while. After about fifteen minutes, attempt to open or close the valve by gently working it back and forth. If it’s still stuck in place, don’t force it.

Instead, reapply the oil and allow it to sit. In some cases, you might need to let it sit overnight. The extra time will allow it to slowly seep into the valve, working to tackle the problem. If the problem persists and the valve won’t budge, you can try heating the oil slightly with a hairdryer. 

Don’t use an open flame, as some penetrating oils are highly flammable. Instead, lightly heat the valve with a hairdryer. Sometimes, this can help the oil penetrate deeper, which may alleviate the problem. 

If slightly heating the oil doesn’t help, we recommend calling a plumber. It’s best not to force these things, as the result can be unpleasant. We certainly don’t want to deal with a cracked pipe or snapped valve. 

Read through our guide here if you want to troubleshoot the problem further before calling a plumber. 

Can WD40 Be Used On Plumbing?

WD-40® Specialist® Water Resistant Silicone Lubricant with SMART STRAW® SPRAYS 2 WAYS 11 OZ

Absolutely – WD40 is safe for use on plumbing. So, if you have a stuck water shut-off valve, consider using WD40 to loosen things up. Many folks, especially avid DIYers, have WD40 on hand, so it might save you a trip to the store. 

WD40 is a non-lethal solution that won’t damage or dissolve the pipe or the threads. WD40 contains several anti-corrosive compounds which can help loosen and remove rust or oxidized metal. 

It can reach into small, cramped spaces, effectively lubricating threads and joints. Most WD40 cans come with two different spraying options: one with the little tube, the other straight from the can. The tube allows you to spray the oil in tight spaces, which can be helpful when dealing with a stuck water shut-off valve. 

Frequently Asked Questions (FAQs)

How Do I Prevent Stuck Water Shut-Off Valves?

The key to preventing sticking water shut-off valves is regular use. Since most of us don’t turn the water shut-off valves unless there’s an emergency or we’re tackling a plumbing project, the valve goes unused for months or even years. 

So, to prevent sticking, turn your water shut-off valves on and off periodically every few months or so. This will help keep the valve mobile and prevent corrosion from taking hold. 

If the valve is leaky, make sure you fix it instead of placing a bucket underneath it and calling it good. Generally, the process is pretty straightforward and requires removing the handle, packing nut, and old washer. Then, you can replace the washer with a new one and reinstall everything else.

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