“P” trap leaks on the tapered ends that do NOT use a gasket, but compression to seal connection. How do I stop the leak?

You could use some teflon or pipe dope on the compression joint and see if it works, or simply replace the p-trap. If you are thinking about replacing the trap, before you do, just tighten the nut as much as you can by hand, then snug it a little more with a pair of pump pliers(channel locks). Please do let us know how things work out. Lee.

When I have the problem that you are describing I coat the face of the beveled joint with some rectorseal.

Thank-you for your interest and help. I applied silicone to the matching bevels, under the compression ring (nut) and to the threads. So far so good! NO LEAKS!!

Thank-you for your interest and help. I applied silicone to the matching bevels, under the compression ring (nut) and to the threads. So far so good!! NO LEAKS!!!

They also sell an epoxy that I have use as a last resort.

Those fittings that use compression do have gaskets of sorts.

Look at the "washers" at the bottom of this page: Tubular bathroom drain products and p-traps and sink drains from FAMOUS PLUMBING SUPPLY (http://www.plumbingsupply.com/tubularparts.html)

To help seal, use a small amount of plumber's (Silicone) grease.

Inspect fittings for burrs.