Best product to clean Teak furniture

[Jay Jolliffe]

I have some Teak furniture that has turned black in places. It get's washed & oiled every year but seems to get darker as yrs go by. I need something to bring it back so it looks good again....Any Ideas ?

[Jim Matthews]

I've used powdered TSP in water followed by a light sanding.

Oil it afterwards and buff with a coarse pad.

[Julie Moriarty]

Defy makes products that clean and brighten outdoor woods. I used their cleaner and brightener (2 different products) to do a cedar deck. It did a pretty good job. For sealing the wood, I use Defy also. Their Extreme Stain is amazing! I've been running a test with teak and mahogany.

http://i867.photobucket.com/albums/ab233/jules42651/Defy%20Teak%20Deck%20Test/D_test_05_zpsfd695b43.jpg
This picture was taken just after applying Defy Extreme in clear. The left three are unfinished, the right, finished. Mahogany-Teak-Teak (unfinished)-Mahogany-Teak-Teak (finished) all screwed to cedar boards. The picture was taken last October.

http://i867.photobucket.com/albums/ab233/jules42651/Defy%20Teak%20Deck%20Test/defy_07_zpslktr591c.jpg
This was taken about a week ago.

[Malcolm Schweizer]

Look for Snappy Teak, and also Interlux makes a teak cleaner. There are also two-step formulas that I believe use Oxalic acid as the main active ingredient, with step two being a neutralizer.

[Bill Orbine]

The oxalic acid is good for cleaning greyed/weathered UNFINISHED wood. Including wood exposed from peeling/flaking/worn finishes. It helps bring back the natural color of the wood. But oxalic acid doesn't do much where finish is presented. So just using oxalic acid to clean furniture with worn/damage finish may yield undesired results with appearance. Should that happen, then you may want to strip the entire surface(s) and sand and refinish/oil

TSP or beach is usually the first step I try to clean dirt/mold/grime so I can see the integrity of the finish and the appearance. It does not do much to remove the weathered appearance, in areas of peeling/flaking/worn finishes, if you have any. In most case with existing finished, TSP (or bleach) is all you need if the existing finish is in good shape. Followed by light sanding and apply new finish.