Stay in Tune vol#76
By Luthier Patrick Podpadec
After looking over some of my past articles I found that I haven't spoken much about finishing guitars. This area of guitar repair is probably one of the most important. It separates the weekend guitar repairman from the professional. (along with a vast knowledge of woodworking,patience, and a whole host of other skills) For years I did not offer my repair services to the public because I didn't own the proper spray equipment to properly “finish” an instrument after I had performed major surgery to it.
After fixing what ever my be wrong with the guitar, mandolin, banjo, etc. there is often times where a touch up of the finish is required. Sometimes more dramatic than others. Some guitars are already nicked up or scratched from years of wear that another nick is not even noticed or the customer is not concerned in any way of the aesthetics as much as in the playability of the instrument. Of course it is very important to me that I don't add any scratches to anyone's guitar, so a clean bench is always the #1 priority in starting any repair. Making sure that I have not left any loose screws or sharp pieces of anything that might scratch the finish of a guitar. I always comb over my carpeted bench with a very strong magnet after I have vacuumed the area thoroughly. Years ago, when I first started repairing guitars I had a short piece of a .010 guitar string stuck in the nap if the carpeting on the bench and when I took a swipe of my hand over the carpet to clean the bench of some debris the piece of fine steel went right through my pinky finger without me even knowing it. It was when I put my hand on the bench to pick up something else is when this very sharp pain came to my finger. Needless to say I don't clean my bench that way anymore. I always count every string piece that I cut off too make sure that there is not one hiding in the nap of the carpet.
I would be lying if I were to tell you that I have never scratched an instrument while working on it. The best I can do is to minimize the possibility of it happening and when it does and to have the ability and skills to touch it up so that it is not detectible. The problem is that it usually takes ten times longer to fix a scratch than to put one on an instrument so it is very important that it doesn't happen by means of neglect, impatience, lack of concentration or a dirty bench.
Many repairs that have to be performed on guitars that have broken necks for example are almost always subject to a bit of refinishing to hide the repair. The general rule is to “feather in” some dark toner on to the area of repair . When I say “toner” I am referring to a colored lacquer that I prepare so that it covers the damaged area . It 's sort of a very dark 'sunburst “ just in a small area. I always try to use colors that accent the guitar. For example, if the wood is of mahogany I tend to use a reddish color rather than a brown. If it is maple I might use a browner color. It is always different and I am always customizing the color tone to fit the repair at hand. I often use a small air brush for small touch ups. It is much easier to control and also much easier to clean up. I mix these toners in small batches and then just add them to a bigger mix later on when I have a bigger spraying project that needs a pretty dark toner.
Many customers do not realize the work that may go into refinishing an instrument. Even for a very tiny nick or scratch it often requires at least 3 to 5 drop fills . This is where I would take a small pipette or tooth pick of clear lacquer and fill the nick with it. When you first put on a drop of lacquer it looks as though you'd be sanding it all away but in a couple of hours the lacquer shrinks back dramatically. It's common to fill it at least 3-4 times before waiting 24 hrs to sand the area flat. Then with a succession of very fine sand paper you can get it smooth enough to buff out. A lot of work for a silly little nick. I often try to talk the customers into living with the battle scars ( not the ones I make, I fix those ) rather than trying to perform unnecessary “plastic surgery” to something that doesn't hinder the sound of the instrument. After all , some wear and tear adds character to a guitar. Look at Willy Nelson's guitar. It still sounds great! I know that's a bit extreme but you get the picture. Lacquer takes at least 14 to 21 days to cure hard enough to sand flat and buff out. Many times during when you are sanding the finish you will come across a small area where a previous crack or joint that wasn't filled or sealed properly will suck up the lacquer and it will require you to drop fill more lacquer in the spot. Sometimes you feel like you will never be finished with the project.. It's very important to sand the finish completely flat before buffing it out. I always start out with 400 grit and work my way to 800 grit before I use the buffer. You can tell that you have sanded it properly after you cannot find any shiny spots on the finish anywhere. It should have an even, dull appearance. The longer that you can wait for the finish to cure the shinier it will become when you finally buff it out. The hard part is having the patience to wait.
There are many new waterborne finishes out now that have been developed specifically for the instrument industry, but as of the present I have not yet used them. For a long time they were hard to use and were considered inferior to the older style lacquers. Newer technologies have solved that problem. Apparently they have a shorter cure time and of course are far better for the environment. I have good intention to start using them soon, but the problem for repair is that so many ( almost all of the instruments prior to 1960 ) where sprayed with nitrocellulose lacquers. Many of the waterborne finishes are not completely compatible with the older finishes. Some guitar builders feel that the new water finishes never set up hard enough and tend to have a “plastic” look and feel . There will probably always be some sort of controversy about the types of finishes that are best for musical instruments. I guess we will have to wait it out to see who is right. Well until then I bid you a “Fair Well!” and please remember to Stay in Tune!
Patrick from Wood-n-Strings / Liam Guitars