I seldom use real cork anymore. Valentino synthetic cork lasts longer. I have used two Valentino sheet products for this. First I used the “tan sheet” on the left. But the correct product for tenon joints is the “cork sheet.”
The tan sheet is more rubbery, so it grabs or drags in the female part of the tenon. This is why I originally started using Teflon plumbers tape to make it so the joint is easy to assemble. I still use the tan sheet when I want the drag. For instance, some clarinets have a very short center tenon. Using the tan sheet on that kind of joint is helpful. The regular (spotty and lighter colored) cork sheet is slicker and don't drag. Tenon joints made with that material generally don't need any grease or Teflon tape.
Valentino tenon corks do not compress as easily as real cork does.
That is true unless the instrument gets way too hot. (As in, in the back seat of a car in the summer sun.)
Tenon joints using the new-style Valentino cork don't seem to need lubricating, but if you do want to make assembly easier, use Teflon plumbers tape according to the directions given below.
I am AGAINST using cork grease. Grease attracts dirt— lots of dirt.
Lubricating real cork joints:
I normally have used thick lip balm. I have tried using Teflon plumber's tape on real cork, but don't like the result. It can work fine on new cork. But if the cork is old, it compresses under the pressure of the successive layers of Teflon tape. The result is that you have to keep adding more tape and the joint always seems too loose.
[July2012] In the process of changing to Doctor's Products bore and key oil, Omar sent me some Doctor Slick. I like it and even use it on Valentino corks if they are too stiff. Of course it doesn't matter what you use on synthetic cork.
“Doctor Slick” Cork Grease from doctorsprod.com:
Cork is wood too and petroleum based cork grease with eventually destroy the cell walls of the cork and they will rupture, collapse, and not rebound as they should to give an airtight seal. Cork cells are sealed cubes and the cell walls are elastic which allows the cells to be compressed and then rebound to their original shape and petroleum will shorten this capability. Petroleum products will also dissolve the glue holding the cork to the tenon – called spinners which I am sure that you have seen in your work.
Emergency tenon cork repair:
It's the night of the concert and your tenon cork joint has just disintegrated! Now what?!
If there is a lot of unevenness in the remaining cork, remove it. Wrap the joint with dental tape, dental floss, or even thread. The waxed dental floss/tape works the best. If available, apply Teflon tape over the wrapping for a better seal.
If your Valentino tenon cork gets too loose:
There are two things you can do:
First, try just leaving the tight joint together overnight. This will compress the cork.
Wind a layer of Teflon tape on the cork and gently put the joint together. If you can't put it all the way together, just put it part of the way. Then leave the joint together for several hours to compress the cork. Keep doing this until you can put the joint all the way together. A somewhat tight joint will probably last a long time.
Second choice: Many have found that using cork grease or other similar lubricant will work until the synthetic cork finally compress enough.
Lubricating Valentino cork tendon joints:
This is for either old-style or new-style Valentino cork joints.
Use Teflon plumber's tape, sold at every hardware store, the thin kind that comes in the blue and white roll.
Teflon tape is so very slick! And it won't attract dirt. The problem is, it's so slick that it slips right off the joint when you put it together. But Teflon will stick to itself! The trick is to get your first layer to stay put, then adding more layers isn't a problem. So here's what I do:
Note from Vintagemusic:
Phil recently reconditioned my clarinet using the new, light-coloured, Valentino cork on the tenon joints. The tenon cork is holding up very nicely. I have noticed, though, after six weeks of almost daily use, that the cork has lost some of the initial slipperyness, so I periodically apply a very thin layer of cork grease on it (not Phil's favorite, I know!). It still requires much less greasing then traditional cork.