A few thermosetting wood adhesive tannin resin system from formaldehyde reaction with both condensed and hydrolysable tannin has been developed. Polymerization of formaldehyde with mimosa tannin and valonia tannin was carried out at optimal conditions obtained from literature to establish the adhesive resin formulation. Formed reaction products were characterized by FTIR spectroscopy. The possible adsorption mechanisms for the adsorption of various metal ions onto tannin-formaldehyde resins were proposed. Also, thermal analysis were studied and discussed by differential scanning calorimetry and thermogravimetry. (c) 2006 Wiley Periodicals, Inc.