Volume 23 - Spraying Lacquer

Written by Patrick Podpadec on . Posted in Northcoast Voice

   

                                     

  Stay in Tune                                                     vol# 23

                                                                                                   By Luthier Patrick Podpadec

 

Can you believe that it is coming up on 1 full yr. that I have had the wonderful experience of  writing these articles. Where does the time go? I hope that the articles that I have written have been a good source of information for all who have read them . I have been told by quite a few people that they have learned a thing or two about there instruments and that always makes me smile. I have recently been approached by a high school student that was looking for some guidance in his quest to build an electric guitar for his woodshop class. How cool is that ! I can remember wanting to build a guitar myself even back as far as my high school days ,but unfortunately there was not anyone in the vicinity or at least at the time I didn't know of anyone to ask about how to go about it. I believe I could only find 2 or 3 books on the subject back in the early 70's.  Back then the art of lutherie still had this “mystical “ secrecy about it .If you were lucky enough to find someone with some experience in building or repairing guitars it was often hard to talk them into teaching you anything.  I never knew exactly why that was it just seemed to be that way.
    Well, that has all changed. Today there are literally hundreds of books, articles, websites, periodicals and even local entertainment magazines that you can find information regarding the art of instrument making. I just  got an email the other day from someone that is hosting a new site that is called guitarbench.com  that hosts luthiers creations and many other guitar related articles . This site is going to be one of the main venues that is promoting the “Sonic Sitka“project that I'm involved in. It will be a place where all of the luthiers involved in the project can post pictures and info on their guitars. I would like to give the readers of the voice a small preview of my “near finished” guitar even before I send it off to anywhere else.  (insert pic)

   The guitar is now patiently waiting for the lacquer to dry between coats .The anticipation is driving me crazy ! I want so desperately to hurry up the process so that I can hear it being played. But this is the point in the building process that is probably the most important time to be patient. It's very critical to let the lacquer properly “cure” so that it does not excessively shrink after you have buffed it out. The recommended time is 4 to 14 days after the final coats of lacquer have been applied. (the latter being the more preferred) Unfortunately I will be somewhere in about 7 days tops to let my guitar cure before I have to get it ready to take to the show in Florida. This is how the finishing process is accomplished.
   You first start out by sanding the entire guitar with 220 sandpaper to remove any and all  scratches that you have previously made. You would then fill the back and side wood (mahogany, rosewood, walnut  and many hardwoods). with a filler compound that levels out the tiny “pits that are visual in the grain,  This is not necessary in woods such as maple or sycamore because they don't possess the tiny “pits in the grain patterns like other hardwoods do. If  you didn't fill these impressions, you would have to apply too many coats of  lacquer before you could get the finish  built up enough to be able to fill the tiny “pits “.There are a few different types of filler ,but the easiest is actually to use drywall compound and stain it with water soluble pigment to match the color of wood that your filling. It's best to try to tint the compound a shade or two darker than the wood because if the filler is too light in color it starts to take on a polka dot look to the wood . A little bit “spotty”.
  You just work a small amount of compound in to the grain by rubbing it across the grain . After allowing it to thoroughly dry (about an hour) ,you can lightly sand off the excess with 220 sandpaper. Be careful not to sand all of the compound out of the tiny impressions.
  You then spray two “thinned coats  of  lacquer  about ten minutes apart.(thinned 1:1 lacquer /lacquer thinner.) After about 1 hr or 2 you lightly sand with 320 to 400 wet/dry paper with a liberal amount of water as the lubricant.. Being very careful not to let the paper “load up with gummed up lacquer because at this point it is still very soft. It's not critical that you get this coat perfectly flat because it is more of a wash coat to get started. You can at this point start to apply what is called the “build” coats.  This is a mixture of about 3:1 and  That is you add about 25% of lacquer thinner to the lacquer. You spray two “wet” coats   within about a ten minute interval First coat up and down and the second coat back and forth. Trying to keep a steady movement of the spray gun to avoid any excessive build or possible runs. After about an hour this can be very lightly sanded flat with come 400 grit wet/dry paper .( again with water as a lubricant.)Repeat  the two “wet” coats again and let it stand undisturbed for 48 hours. After sanding the the last 2 coats of  lacquer flat you can proceed with another 4 coats just like before and let it sit again for 48 hrs. At this point if your lucky (or skillfull) you should have enough “build” to proceed to the final coat . This is usually thinned about 33% with a slow drying thinner known as a retarder so that the lacquer will flow out nicely  which results in a very flat and  glossy finish with little buffing to bring it up to a brilliant high gloss finish.Well please look for more pics and info on My Facebook page or the guitarbench.com  site for more info on mine and many other guitar makers from around the country.  Like my good friend used to say “Keep on Smiling” and we'll see you next time! ( insert pic 2 if there is room)

              Thanks Again !
                 Patrick from Wood-n-Strings