Teak is naturally oily ... nothing sticks to it for long.

Get some "teak oil" meant for caring for teak furniture, and follow the directions for applying it.

Use place mats, don't use pointy pens and sharp knives on it, and don't let toddlers with magic markers near the table

"Teak Oil" can be any kind of product the manufacturer wants to put in a can and sell as Teak Oil. Much of it is simply a very thinned varnish, or a very thinned varnish-oil blend. The former, you can build up a film finish on, the latter will only get gummy if you try to build a finish with any degree of film. If you have some, you can tell what you have by putting a few drops, making a small puddle on a piece of glass, lay it flat, and let it cure for a day or two. If the puddle becomes hard and smooth, it's varnish. If it's wrinkled around the perimeter, it's got some oil in it -- the more wrinkles, the higher proportion of oil to varnish. The more oil, the less protection it will provide and the less film you will be able to build. Oil-varnish finishes are meant to be "in the wood" finishes, not film finishes.

Most teak is not factory oiled, it's lacquered with a very flat lacquer. It's a common misconception that this is actually "oiled."

Now as far as "slapping on some poly*" (my words, not yours, you said "painted"), it's not really a good idea. Yes, teak has oils that interfere with finishes and their adhesion. Veneers and plywood are less oily than solid woods (most table tops are made of veneer). Hopefully the existing finish has sealed in most of it. But poly already has a hard time sticking to something else, particularly, if the poly is applied too thickly*. And if anyone has ever used Pledge furniture polish on it (likely so over the last 50 years), the silicone oil will cause the poly to fish eye like crazy.

When I've refinished teak, I've stripped of what was there. Immediately before applying the first coat of finish, I wipe with a rag soaked in acetone to remove any wood oils. Then I apply a couple of coats of dewaxed shellac. This will seal in any silicone oil. Shellac works well on oily woods and also becomes a barrier coat for whatever finish I want to put on top of that. Shellac also brings out a lot of chatoyance in the wood.

I'd recommend loving it for what it is, treating it gently, and when that 50 year old finish is ready to go (which it may be already), stripping and finishing with a stronger film finish.

Thank you to both for your advise. This helps me a lot. WIthout your input, I'm sure I would have had a real mess on my hands and a ruined table.

You could use pure Tung Oil, I use it on my teak floors and love it. Put it on raw wood, let it sit for 40 min then wipe off. Just mix 50/50 with mineral spirits. Let dry overnight and do it again until the wood stops soaking up the tung oil.

I agree with lazygardens.Teak oils are specially designed products to keep the teak strong and beautiful. Use an oil such as Teak Guard to treat the teak with oil. Apply the oil to a clean and dry teak surface by wiping the wood with a rag soaked in the oil. Apply as many coats as the label of the product directs or until the teak has acquired the color you want.

This post was edited by joseph004 on Mon, Mar 25, 13 at 3:44

Another question on teak...my wife recently purchased a teak dining room table from Crate and Barrel. The model is called Terravida with Grey Wash. It's made of reclaimed teak and comes with what appears to be a water based stain. Several reviews on the Crate and Barrel website complain how easily the water based finish is damaged.

Any recommendations for sealant? I've done some online research and it looks like teak can be challenging to seal due to oils in the wood. The manufacturer's care says "Do not use waxes in the form of liquids, aerosols, or sprays." However, one reviewer says bees wax works well.