The number of sealer coats to apply depends on the viscosity and solid content of the product. If the sealer is liquid and has a solid content below 25%, it is recommended to apply two coats to effectively seal the wood pores. However, if the product is slightly thick and has a solid content higher than 26%, a single coat should suffice. It is important not to apply more coats than necessary, as the sealer should not be used to build thickness but rather to seal the wood pores so that the lacquer can adhere properly.