You can overtighten the nut (and other plumbing parts that have gaskets) and actually cause leaking issues so be sure not to go crazy on it. Tightness is realitive but it should be tight enough that once you're done you can't twist it by hand and it doesn't move when you tighten the drain pipe back on.
Tighten the large nut as tight as possible, if the entire strainer assembly starts to turn, hold back on it with another pair of tongue and groove pliers on the 1-1/2" threads carefully so you don't damage them and tighten the strainer nut very tight.
Smooth surfaces, new sink, gasket, nut, I've never had to more than hand tighten. But, I'm pretty strong. If you are in doubt, snug it up just a little with a wrench, and check for leaks. Plastic parts, and lightly made metal could distort or even break under too much stress.
If you discover that the water is draining away then your basket strainer/plug is faulty and you do need a new basket strainer waste/plug or rubber seal. If you are within warranty you can probably get this free of charge, otherwise you can purchase replacements from most retailers – we have them on our site here.
Another word of caution here is that the average person can't always tell if they've over-tightened or under-tightened a pipe… See, one of the top bathroom sink drain installation mistakes to avoid is over-tightening connections to the point where they crack or strain.
We suggest you tighten the nut, bolt, or machine screw by hand until it makes contact with the washer or the surface of the workpiece. Then, using an adjustable wrench or a socket wrench, make a consistent number of turns to ensure that all the bolts have the same torque.
Unfortunately, you can do damage by overtightening, too. If you over-tighten the drain plug, you can strip the threads.
Apply putty and reset the basket
Roll plumber's putty between your hands into a rope the size of a pencil and wrap it around the lip of the kitchen sink drain opening. Press the kitchen sink strainer firmly down into the putty, add the rubber gasket, friction ring and locknut under the sink, and retighten the locknut.
The main difference between plumbers putty or silicone for sink drain is how easy the substances are to manipulate or remove. Plumbers putty is very easy to manipulate into tight areas, and it's also easier to remove. That makes silicone putty better for waterproofing, even if it's more difficult to work with.
Arguably the most common reason you'll find water beneath your sink is that your drain has a leak in it. Shifting plumbing lines, worn-out connections, or even pipe corrosion could cause fractures in the plumbing lines beneath your sink, which cause water that flows down your drain to slowly and steadily leak out.
The compression nut is loose: This is probably one of the most common reasons for a leaky drain pipe at the connection.
There is no simple answer to this as in some instances, it is perfectly acceptable to tighten the bolt head while holding the nut in place. In other situations, it's acceptable to tighten the nut. It all depends on the application and the condition of the product or material being worked with.
One common reason for sink clogs is due to material like hair and soap scum becoming lodged in the “P-Trap” under the sink. It is quite literally shaped like the letter “P.” A P-trap is a plumbing fixture that has several purposes.
Most bathroom sink clogs result from a combination of hair, dirt, and skin flakes that bind with the gooey soap scum that accumulates on the walls of the drain pipes or gets caught on the pivot rod or stopper of the drain.
To prevent sewer gasses from entering your living space. The pipe bend known as the trap ensures that there is a water seal separating the sewage system from the inside of your home.
Filtering solid debris from entering your plumbing system with a mesh screen, strainers prevent clogging that can lead to system malfunction. When water and liquids pass through a strainer, the debris basket blocks troublesome items from going down the drain, offering an easy way for scraps to be discarded.
You need a tool called a basin wrench. These special plumbing tools have a long handle with a tee on one end so you can get leverage. The other end has a spring-loaded adjustable wrench head that grips onto the nut.