Many species of hardwoods have open pores in their grain. This presents a challenge when trying to finish them with a lacquer or varnish because these finishes do not fill the open pores very well and this leaves tiny voids that do not appear smooth in certain light. Ziricote and Ebony are closed-pore woods so nothing has to be done to prepare them for final finishing. Mahogany on the other hand is an open-pore wood and needs to have the pores filled before finishing. Many different kinds of fillers are used but the process is similar: force the filler in the pores with different strokes from different angle. I am currently using Zpoxy, an epoxy-based substance that does a great job at filling pores.
After the pores stop accepting any more filler I do a final smoothing out so there are no peaks in the Zpoxy and I hang it up to dry.
Once the Zpoxy dries, I will sand it back to the wood leaving only the filler in the pores. Sometimes I have to repeat this process to completely fill the pores (especially with Rosewoods) but a close inspection with the magnifying glass reveals the pores are sufficiently filled.
The guitar construction is now finished and ready for the lacquer. I must first clean the shop of excess sawdust and debris and then I will set up my spray booth.