Birkenstock sandals and clogs with exposed cork at the edges of the footbed (most Classic Footbed and Soft Footbed styles) come with a layer of cork sealer applied at the factory. You will notice that the cork on new sandals and clogs looks shiny.
Over time, the cork sealer wears off and the cork will begin to appear dull. This is when it's time to reseal. A single, thin coat of sealer is all you need.
How often cork sealer needs to be reapplied will vary for each pair of Birkenstocks, depending on how often the pair is worn and your individual wear pattern (for example, if you scuff your heels together as you walk, you may need to apply sealer to those areas more frequently). Check your cork each season, and reseal as needed. There is no need to apply sealer to cork that still appears shiny.
Birkenstock makes a cork sealer that comes with a convenient applicator. We carry this as part of the Deluxe Shoe Care Kit and also as a stand-alone item. Only apply a single, thin layer as needed. More is not better. A thick coat or multiple layers of this type of sealer can become brittle and crack, which can actually damage the cork, rather than protect it! However, when used as directed, this is the easiest and most convenient way to care for your cork.
In our repair shop, we use Barge Cement to bond our repairs and also to seal cork. Barge Cement is a contact cement that remains pliable once dry, though you still only need a single, thin layer to reseal cork. We carry small tubes of Barge Cement for at-home use. Apply in a well-ventilated area, because this product does give off fumes. With Barge Cement you will need an applicator, such as a small brush.
Please refer to individual products for specific application instructions, or call us at 785-841-7027 for advice.
NOTE: Birkenstock Exquisites and other styles where the cork is wrapped with leather do not require cork sealer. Birkenstock shoes and boots, which have removable cork footbeds, also do not require cork sealer. Only apply cork sealer to exterior-exposed cork.