Carpet seam sealer is an adhesive sealer used to seal the edges of carpet to prevent it from unraveling before it is installed. It is not intended to glue the edges of two pieces of carpet together - that is what seam tape is for. Seam sealer is usually applied to carpet edges before it is sealed with seam tape.
Applying Seam Sealer
The primary complaint related to seam sealer is that it gets on the exposed surface of the carpet, or is applied too thickly creating a hard, or visible seam in the carpet. More is not better. Only apply sealer to the base of the carpet backing edge, or the base of the carpet nap. Apply the sealer with the tip of the applicator, then use your finger or the applicator tip, to smooth the sealer into the raw edge or fibers of the carpet. The sealer should keep the yarns or threads of the carpet from pulling free from the backing.
Things To Avoid When Applying Sealer
Avoid putting too much sealer on the edge of the carpet, or too high up on the carpet base. If you use too much sealer, you'll create a hard seam which can be seen or felt once the carpet is installed.