| Lets start from scratch
Oil Finish
Sitting in front of you is a guitar body and neck unfinished. Its time to do some finish work so where do you start?
It depends on what type of finish you want and also what type of wood you have. The easiest and quickest finish is a standard oil finish. It is not a law but I tend to like oil on any type of grainy wood like mahogany or sometimes ash. Any bass I make with a exotic top or an exotic wood construction other than transparent colors I like oil. Oil finish gives you a more true to life wood feel, but it has its drawbacks. Its hard to keep clean, it wears un-even in the areas that your hand rests and the wood sometimes gets darker after time. I made a bubbinga top bass with a solid mahogany back years ago and it was beautiful when I finished it , but it came back six months later and it was completely black in color from the air. So be careful when using oil.
What type of oil to use. Every one has some idea about this and I only talk from experience. I first started with Watko Danish oil, many other companies like formby's make a danish oil also. This is a great finish but it is sort of dull. I wipe it on with a rag and I have heard stories of the rags catching fire or exploding so be careful. I still use Danish oil on necks but that's about it. Then there is tung oil, it is really almost the same to me as the Danish oil finish so the method for doing this is the same.
Recently I heard that Musicman was using gun oil to finish their necks. I went to my local gun shop and bought Hoppes machine oil and I used this on allot of samples. I thought it was great but when I went back to the gun shop and asked for more they looked at me strange and pointed me at the gun stock oil in a can. So I bought this and now thats all I will use. It sprays on easy, dries fast and has a slight shine to it. I figure if it protects gun stocks from sweaty arm pits then it must be able to handle any musician.
To do an oil finish first you need to sand the body well, make sure every scratch from the sand paper is gone. I never start sanding wood with anything less than 180 grit sandpaper. I feel that even #120 leaves deep scratches that are hard to get out. Sandpaper is used in grades starting with a lower aggressive grit and moving up to a smooth grit to get the previous scratches out.
I generally use power tools to sand the body, if I try to sand by hand there is always some small spot that I sanded too deep and it shows when the instrument is finished. I use an orbital sander that is air powered that I purchased at our local auto body store Bill Flannery's automotive ( They send me a great basket of snacks every Christmas too), The orbital sander works quickly but leaves some circle scratches in the wood that can show up after finishing. To eliminate these you need to sand back and forth with the grain before finishing. For this I use a regular back and forth Black and Decker palm sander. Some people I have worked with use this for the entire process and it seems to work well, but the orbital cuts faster and keeps the paper cleaner longer.
My process on wood is to start with #180 (Some other builder's start with more aggressive paper.) sand with the grain that means back and forth from top to bottom, this way any scratches go with the grain. (Cross grain scratches are hard to remove.) On the top/ back and sides I use the palm sander but on other areas like cutaways or areas that the sander does not fit, I made special blocks that fit in the cutaway's. (I just use large dowels or broom stick handle, cut to size and covered with rubber or felt.)
After finishing with the #180 I move to #220, Then #320 and finally #400 for grainy woods, or woods that will be sealed and sprayed a color. For hard maple or natural finishes I tend to sand higher with #600 and a Scotch brite medium pad because any tinting will show the scratches.
If the guitars body was just made, you need to seal the wood first. Sealing the wood is what we do so that all the grain is filled in so the paint will not sink after finishing. Depending on the wood grain and if the instrument will have a natural finish or sunburst, I prefer staining the wood directly. However some woods like spruce can have a deep grain and need to be sealed first because staining the wood directly can make an uneven color.
If the body is going to have a transparent stain, I stain the wood before any sealer. For this I use alcohol base stains, I have tried many different style of stains from spray lacquer to water based stains but I really prefer the alcohol base. One main reason is it can be easily wiped on and if the color is to dark I can pour alcohol on the color and wipe it down to lighten it up until I get the exact color. Stains are available from a place in Texas re-branch guitars.
To apply a stain directly to the wood you will need to mix up the stain, some companies sell it pre mixed. Make sure the surface that you are staining is clean with no hand oils. Put on a new pair of latex cloves and use a new sponge or a bag of rags. First wipe off the wood with straight alcohol and a clean rag to remove any residue. (Use denatured alcohol.)
Apply the stain directly to the cloth and wipe it on with the grain. Some people use a circular motion to do sunbursts with a darker color on the edge but I always spray sunburst's after I clear over the hand stain. Sunbursts are tough to do, you only have one shot if you spray it directly on the wood. My method is first staining the wood, spray a clear coat over the stain then spray the burst. If you mess up, wipe it off and start again. This has no affect on the base coat that is under the clear. Staining Movie |