well, i would think that the sorghum wouldn't matter to glass and paint since it's on the other side of the wood skin. if you had enough batteries that method would work. i use a 3-4 foam roller from lowe's and a paper plate. just a little glue spread around and then roll it until a complete sheen is on the foam. you hold it up to the light to make sure your coverage is complete. basically the foam is now just wet, that's all, no need for even the glue color to show anymore. mist your skins with water and assemble back into the cores and then between pieces of mdf. 2-3 batteries over that should be enough. the glue will expand well into the foam.