I had a spare maple board which had some nice flame on it so I decided to do some testing with the application of shellac. I wanted to start to get a feel for the process from beginning to end and start to correlate certain issues/events with the stage, so in every stage I know what I am anticipating or need to do to prevent problems in other stages.
This was a maple board with a little flame already visible in it. I am finding that the key to any finishing project is the preparation as in sanding... I have been bringing my surfaces to at least a 320 grit but what is more important I am finding, is that the woods needs to be as level and as smooth as you can make it. I am starting to learn what a good sanded piece of wood in 80 grit is related to 180. You can see this board had some damage on the ends that would need to be taken care of.
Here you can see I have brought the board down to 320 grit which repaired the ends nicely. I have learned so far that really anything less than 200 is for wood removal and shaping. The lower you go the more wood you can remove but you will leave large scratches. That is the purpose of the higher grits. The trick for me so far has been to really understand the removal in the lower grits and assure I am as level and shaped as I can be at that grit before moving on.
My steps in French Polishing have been:
1) Preparation (becoming a larger and larger part of the project)
2) Spit coats - usually 3 coats of French Polish applied. I used a thicker concentration.
Spit coats are applied the same as other coats but a little wetter and with less regard to runs and streaking. Normally I judge the thickness and the saturation of the Muncea by patting it firmly on the back of a gloved hand. The spit coats I will put on fairly wet, not as worried about runs and ridges to a point. The goal here is to apply shellac in a base coat. If the surface is prepared properly all that is needed between the spit coats and building layers is to level.
3) Building layers (Bodying)
The purpose of bodying is to start to build up enough layers to get a consistent flat and even surface. There are several sub-steps to bodying. I won't cover creating the muncea etc, there are plenty of resources on the web which cover this.
The application of the shellac falls into three major components within bodying.
1) Circular rubbing motion
Basic technique of using small circular rubbing to thinly apply the shellac over the wood. You want the muncea to be wet enough where you see shellac being spread very thinly but you will see definite swirl marks and ridges after application
2) Straight "brushing"
Still using the shellac muncea I use the 'airplane' stroke. As you approach the wood, think of the muncea as an airplane making a landing. Brush the wood in the direction of the grain and as you approach the end of the board you take off. This creates a smoother spread surface across the wood.
3) "Stiffing" with alcohol
Using just alcohol and using the airplane stroke I further smooth out the shellac. Alcohol will dissolve the shellac and move it out over the wood. Care must be taken not to 'bottom' out the shellac and move it all to the edges.
4) "Stiffing with alcohol and Pumice"
I only use this if I need some abrasives to move the Shellac around. I normally use Pumice if I have some pitting or runs that I need to take care of.
Here I am showing my muncea getting ready to be applied to the board. My muncea's are in different shapes and sizes depending what I need to do. I have read several resources on making the muncea. I have been primarily using gauze as the inner reservoir and the outer being a t-shirt type of material. I have been considering trying a linen outer covering.
This is after a couple of spit coat applications. You can see it starting to build. To the left I had some issues with the grain being a little more open than Maple usually is. You can also notice the appearance is 'flat', not very shiny. So far I have noticed with the spit coats you will get a 'wet' looking shine but not even and not very reflective. As you get into the bodying you will start to build a shine that can get to a gloss. As you level it will be more matte. Than when you get into the polishing phase that is where you move from gloss -> high gloss to mirror like.
This is after the initial spit coats. You can see there is a base coat of shellac that is fairly even across the board. The flame is starting to become more three dimensional. There is a minimal to moderate shine across the board. Light reflected at this point is blurry. As we build the coats and begin smooth it out the definition in the shine becomes much more clearer. The goal at this stage is to have enough of a base coat so that we can begin to manage and level the surface.
I have gone through at least 3 complete body building phases, used Pumice to smooth out some of the pitting and stiffed it with just alcohol. You can see an even gloss across the board. You can see some ridges going the direction of the grain after stiffing. I have a choice here, I can try pumice which will not reduce the thickness of the layers, or leveling. Leveling is using a felt block (so that you have an even firm surface) with sandpaper to level the surface. Depending on what I am trying to do and where I am in the building I will use as coarse as 400 grit building up to 800 grit towards the end of the project. Right before polishing I can go as high as 1200-1500 before starting with the polishing cremes.
You can distinctly see the outlines of objects in the gloss. They are a little blurry now, but will sharpen up as I continue the process.
Here is the board after several coats and a couple of leveling sessions. You can see the flames are taking on a much more 3-dimensional appearance. As the shellac grows in thickness with more applications, the light is refracted giving it the appearance of another dimension. There are still some ridges but they are much less defined. We are at a matte to low gloss. We have some reflection starting to build but the reflections would not be very defined.
Here you can see the streaking and some pitting of the shellac a little. Depending how severe the pitting or streaking is there are three processes I have at my disposal. One is to 'stiff' the board using a Muncea and just alcohol, no shellac. If the problem is a little more defined I will use pumice and the alcohol. I can also use abrasive wet sanding with sandpaper. I tend to be very judicious with this though. I try to do 3 complete body build-ups before leveling since the process will reduce the amount of shellac on the board. Some repair can be done in the polishing phase, but not much, so it is important to keep on the offensive as you build.
After I have completed the building, usually a minimum of 10 complete body building sessions, usually around 20 - 30 I take a final inspection. If I feel I have enough shellac built up, and a level surface with a minimum of pitting and ridges I can start to look at 800 Grit sand paper. I usually will start at 800, then 1200, then 1500 then start the polishing regime of Med, Fine and Swirl Remover followed by wax. I put the wax on just for an extra protective coat and it responds well to wiping. If damaged it is very easy to repair.
Here is a photo of the board after sanding with 800 grit. You notice it is dull in appearance. There are some shiny spots which are just a slight unevenness. I personally leave it at the 800 stage and relieve it with the other phases of sanding. You could just bring it right down using the 800 so it is even throughout.
The 800 grit has leveled the surface fairly well but it has left major scratches in the surface. The 1200 will level a little more and catch the areas we didn't get with the 800 but the major purpose of the 1200 is to start to even up and remove the scratches left by the 800 grit. As the ridges are reduced the shine will start to come through.
Here you can see the board after the 1200 grit sanding. A nice sheen is starting to develop as well as some three dimensional appearances to the grain. This is where it starts to get fun.
The instructions say if you sand with 800 grit start with the coarse polish. I sanded to 1200 and sometimes 1500 and start with the medium. In the beginning I used power tools to do the application but the time periods are shortened quite a bit and I have definitely sanded through more than once. So on the smaller pieces I am sticking to hand polishing. I take a cotton cloth, fold it several times to create a pad than using the pad simply start rubbing. I want to feel and hear some abrasiveness of the polish against the finish so I add more polish as necessary.
I usually polish for 3-4 minutes than rub off the polish, assess, reapply and continue. I have found at this stage I am more worried about ridges and any deformity in the finish. I have noticed a couple of issues at this stage that I needed to address. One was 'dull' spots. Spots that just weren't shining up. I had to assure myself that there was shellac underneath and then spent some time rubbing it out. I guess I could reapply shellac at this point but they ended up rubbing out for the most part. The other was fine pitting. I was OK with the fine pitting figuring that the fine polish was going to take care of it. If not I had no issue in going back a step and reapplying the medium. In general you want to see no or minimal ridges, fine, not coarse pitting and a shine starting to build. If not you really want to assess if you have enough shellac built up, you spent enough time at the leveling phase building a level surface and that you applied the medium with enough rubbing to get it to that stage. It took me about 15-20 min (3 applications) on this small piece of wood wiping it down in between.
Now time for the fine polish. At this point you should have a good shine going with some of the grain popping. You should have reflection but the definition of the reflection may be blurry which is fine. There really shouldn't be any defined ridges, they should have all been knocked down by the previous process. There may be remnants of the ridges, but they should be very minimal. The pitting should be fine or non-existant, you want to have no dull spots if possible. Like I said, I am not sure of the etiology of these but I am pretty sure these are present before you get to the final leveling. The only way I know how to get rid of them at this stage is to continue to polish and rub them out.
Here you can see application of the fine polish. Again using a cotton cloth I simply rub it, same as for the coarse, 2-3 applications and lots of rubbing. You will start to notice a definite shine and 3-D appearance starting to build. Reflections are getting much clearer at this point. If you are trying to achieve just a gloss or a matte you could finish out here. If you want to temper the shine using some 0000 steel wool before your wax application would work. I am going for the mirror, so onto the next step.
Here is a photo of the board after the fine polish. Notice the reflection is much more detailed, the woods has a definite 3-D appearance and everything looks fairly finished. All the swirl remover is going to do is increase the shine and reflection so you want no ridges, no pitting and no dull spots at this point. The quality of the reflection (Shine) is what we are working on now.
Time to apply the swirl remover. I notice a definite change in appearance when I apply the swirl remover. This is probably my favorite part since I know I am almost done and the change can be rather dramatic if you have done all the previous steps correctly. The downside to this particular part of the process is this is where you really find out if you did do the other steps correctly. You can get to this stage and have some issues start to appear that were always there, but now they are more noticeable. Not a good feeling ;-)
Here you can see the board after the swirl remover is applied and quite a lot of rubbing. Again 2-3 applications with rubbing it clean in between. You can see I have good definition, very good 3-D looking grain and the flame came through very nicely. At this point I apply wax for a couple of reasons. One is wax adds a protective coating. Very easy to repair and it responds well to wiping. So as people touch and hold and deposit their finger oils all over it, wiping it down well will get rid of it and restore the luster, a win-win.
Same process, 2-3 coats and lots of rubbing. At this point you can just rub and rub... Notice that with every rubbing session, the definition of the reflection just becomes tighter and tighter. I could actually read the writing on the bulb in the reflection. The grain has a great 3-D appearance and I am just about done.
I tried a lambswool buffing wheel on the edges of this board but it quickly burned through. Guess I will need to practice this technique more, so I stuck to hand buffing.
Here is the finished test board after shellac applied, sanding, polishing and buffing all done. I would say about a 2 month process. On a finished guitar probably about 3-6 months depending on what you are trying to do and how much drying or gassing off time is permitted. I have read that the gassing off process will continue for a year after. All in all a very satisfying process. Not for the week of heart or impatient person, but I thoroughly enjoyed the process.
I left the strings in place, taping them off at the the bridge and removing them from the tuners. Then I unscrew the screws that is securing the pickguard in place. There are 11 in this particular pickguard and 8 in the replacement. After removing the screws I normally take all the knobs of the pots and take of the retaining nut so that all the electronics can fall into the guitar. I also unscrew the pickup holders.
