Finishing

Home Up

Applying finish to a musical instrument has very few set rules chiseled in stone and the options might be as great as the stars in the sky.  Each Craftsperson has his or her own ways and methods of applying finish and have their own merits and detractors as well.  A large manufacturing facility geared toward production will no doubt have the latest in technology available with some robotics driven by CNC programs and the results usually justify such a huge investment.

There are plenty of reference books and materials available with in-depth study to address musical instrument finishes.  One of my earliest acquired books is VIOLIN-MAKING by Ed. Heron-Allen published by Ward Lock and Stewart MacDonald has a good reference book  Finishing Step-By-Step  for duplicating old and current finishes as well.

However, this banjo will certainly not have such benefits, not even a spray booth or any high technology spray equipment but about as meager as you can get; well the Lynx spray gun might be above the meager level...grin if you must!  I have a small spray touch up gun left over from my music days; a DeVILBISS EGA-502 of which they still manufacture this little spray gun today but the new model is EGA-503 and basically it is identical.  I also have a Lynx L-300H 1 quart pressure feed HVLP spray gun manufactured by CATechnologies that I used on outside yard decor and obtained a smaller tip/nozzle 1.3mm, etc. for it and will probably use it for the lacquer top coats and the EGA-502 for the application of the sanding sealer before and after the usage of the mahogany wood filler. 

SAFETY

The majority of the finishing products I have used over the years are certainly hazardous to your health if not used properly and in a well ventilated area.  Most small shops and individuals making an occasional instrument do so without the benefit of a dedicated or portable spray booth set-up and are at the mercy of the elements since spraying has to be done outdoors or in an open doorway or window area to allow the toxic fumes to escape.  A good dual canister respirator with appropriate charcoal filters is a must for the higher VOC (volatile organic compounds) products; e.g. nitrocellulose lacquers and thinners, and rubber gloves either the heavy duty kitchen type or the inexpensive disposable medical type should be worn.  There are plenty of free information on the web for the construction of a permanent or portable spray booth and will not venture into that area.

STAINING

For the staining of the wood rim, resonator and neck, I will be using alcohol based, non-grain raising dye stains made by Behlen Master Solar-Lux  and one of unknown origin; only has the stock # and color ID on the bottle.  I believe I purchased it when I made my Reso guitar back in 2000.  In the past, I used acrylic automotive lacquer made by DuPont which that particular product is no longer made and planned to use Lawrence McFadden products and unable to get them at this time,  so settled on Mohawk Finish Products which is a division of RPM Wood Finishes Group, Inc. located in Hickory, North Carolina.  They are readily available here in NC and can obtain them at a discounted price of which several of the top custom instrument makers using their products and it is to my understanding they produce the Behlen line of products as well.

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I masked the fingerboard area off and left a little gap between the binding and the fingerboard which reduces the chance the finish will be chipped when removing the masking tape for final scraping/cleaning of the fingerboard, etc.  I found one of my neck holding handles from the 1970s that still has some of the RB800 red lacquer still showing and bolted it to the neck hanger bolts using a couple 10-32 tpi nuts.  A plastic "tarp" was placed over my router table which will be the staging area for spraying and will raise the basement garage overhead door when I start spraying the sanding sealer and top coats of lacquer.  The sanding sealer and lacquer are dangerous to your health and you need to be in a very well ventilated place while spraying those materials.  Many states are banning the use of similar products but there are no suitable water based replacement products that will give the same results as the nitrocellulose lacquers for musical instruments; at least that is my opinion and I am not alone either!

I stained the wood rim earlier with a maple stain but thought it was too light even with several coats applied and went with a darker walnut color which did darken it up.  I used a piece of cotton tee shirt material to rub the stain with the grain of the wood rim and the resonator and those aniline dye stains are permanent so put on a pair of disposable medical gloves to prevent dyed hands...grin if you must!  It might take several applications to get the desired color and keep the wood rim wet with stain and overlap and evenly spread the stain to prevent streaks.  After you have the entire part stained, lightly go over it to fully blend all areas before it has a chance to dry.  Before the spraying takes place, I will insert an auxiliary handle from a Milwaukee 1/2 inch electric drill of which the bolt threads are perfect for the 5/16 inch diameter lower coordinator rod hole in the wood rim and the handle will allow me to control the wood rim while spraying sealer and the finish top coats.

It is not necessary to tape over the neck and resonator binding since the stain will leak under the tape most of the time anyway.  Use caution around the peghead area since you don't need any stain on the peghead overlay or outside of the nut.  If you do get a little stain on those areas, they can be scraped/sanded clean before the top coating of sealer and lacquer takes place. 

The longer the stain dries, the less chance there will be bleed through when applying the sanding sealer and/or wood grain filler which ever one you elect to do first, however mismatched incompatible components are the main culprit.  I plan to apply a thin wash coat of sanding sealer before the application of the mahogany wood grain filler since mahogany has been know to bleed through a few weeks and months after application of the top coat.  It is imperative that the dye, wood filler, sanding sealer and top coat products are all compatible with each other and you need to follow the manufacturers protocol for the application of their products.  It is also very wise to do a test run on scrap similar material to verify your end results

SANDING SEALER

Notice my last sentence above...do a test run.  The stain aka aniline dye had plenty of time to dry and started getting my materials and equipment ready for the application of the sanding sealer over the stain before the paste wood filler and planned on using the little DeVILBISS EGA 502 touch up gun, however after loading the spray gun to do a test pattern on scrap material, it would not pull the sealer from the glass cup.  I quickly ran some solvent through the gun and nil, nothing but air and had to put that spray gun aside for a later complete take down.  Luckily the CATechnologies Lynx L-300H HVLP gun was operational and a few adjustments to the air and material flow screws had a decent spray pattern going on scrap material.  I was unable to take pixs while actually spraying the parts but you should get the picture without them.....no pun intended.......grin if you must! 

 

A two stage air compressor with a tank large enough to keep from quick recycling is an advantage to prevent rapid starts which can show up on large spray patterns areas such as cars, etc. but would probably not be noticeable on musical instruments.  My single stage 6HP air compressor is ok for my home projects but if I were doing musical instruments for a living, I would get a better outfit and a spray booth set-up for sure; either home grown or store bought.  On the flip side of the coin, some like the smaller units that recycle more often keeping the air supply hot instead of cold reducing the moisture condensation in the air supply line.

Mohawk does not recommend thinning their sealer and it sprayed and atomized very well with the 1.3MM tip/needle combination in the Lynx L300H spray gun with the pressurized cup.  I also have a cheap gravity flow gun with a large 2.2MM tip/needle for spraying heavier materials for yard decor projects, etc. and definitely not suitable for the sealer and lacquer applications.

You will notice the holder I am using for the wood rim is an auxiliary side handle off a Milwaukee 1/2 inch heavy duty electric drill and the attachment bolt threads worked perfect in the 5/16 inch coordinator rod hole for the tailpiece and gives you plenty of room to spray the wood rim around that area.  I have a close up pix of the headstock which shows the porous nature of this piece of Honduras Mahogany and it would take a lot of top coats to fill the grain without a paste wood filler application to seal and level the wood pores.

I will probably wait at least several days to a week before lightly sanding the neck and resonator down since there is rain in the forecast for the next several days and humidity is definitely an enemy to finishing.

Before I do anymore spraying to the resonator, I need to find a lazy Susan type fixture or turntable since the coffee can is about as rube snorkel as you can get, unless you can walk around the entire resonator while spraying which is about what I had to do on this one.  It was very difficult to try and rotate the part and/or coffee can without some type of rotating base plate.  I certainly did not do my homework on spraying the resonator.  Since I plan to do the neck notch cut out in the resonator after finishing, I could just as well drilled a hole in the waste material and used another drill auxiliary handle but will find a simple rotating base instead.

The small DeVILBISS EGA 502 touch up gun was taken apart and re-cleaned, however I did notice build up in the glass materials cup and the feed tube had remnants of the white primer paint from my last yard decor project and poor cleaning was the culprit.  I ordered a parts kit for the gun; the gun is replaced by the EGA 503 which looks identical and the EGA 503 parts also fit the EGA 502 which is a good thing.  According to the price of the repair kit, there had to be some platinum used in their manufacture!  I ordered a spray gun cleaning kit and with the repair parts kit and will refurbish the gun before I spray another coat of sealer after applying the mahogany paste wood grain filler and the top coats.  The ole sayings, "An ounce of prevention is worth a pound of cure" and "a stitch in time saves nine" rings very true on this one.        

PASTE WOOD FILLER APPLICATION

I will be using a mahogany paste wood filler # M608-4238 filler manufactured by Mohawk and they recommend thinning it down 3 parts filler to 1 part thinner.  Since I did not order any paste filler reducer from them, an oversight on my part, I called their customer service and they said I could use Naphtha or mineral spirits to cut it with.  I thinned the paste filler until it was the thickness of a thin custard filling and a little thinner than sour cream and cut plenty pieces from a burlap sack to rub the filler into and off the parts.  As everything else about this project, it has been decades since applying a paste wood filler and I probably could have gotten by just as well without using the paste wood filler and elected to spray a few more top coats and sand them down.  However, a filler in the open pores of woods like mahogany, walnut, rosewood, oak, etc. can add extra eye appeal to the project, especially if the filler is a little darker than the stain which gives a good contrast.  Gibson during The Great Depression Era filled the open grained woods they used such as Brazilian rosewood, mahogany and walnut for their guitars and banjos.  I did a little testing of the wood filler on scrap mahogany before applying it to the resonator and neck and threw all caution into the wind and went for it.  I applied the paste wood filler using a cheap stiff plastic bristled brush and packed it into the pores and went then brushed across the grain to aid in getting the wood filler into the pores.  It only took a couple minutes before the paste wood filler glazed over and it was then time to rub the filler into the wood using a figure eight pattern and then across the grain.  I finished up lightly rubbing with the grain.  I did only small areas at a time since the thinning agent dried out very quickly.  I will let the resonator and neck set a few days and go over them with 0000 steel wood rubbing with the grain and try and polish down to the filled pores since there is a wash coat of sanding sealer under the wood grain filler and should get the parts back to the red mahogany aniline stain color.  This product tinted the parts more brown than red but it should be ok either way it turns out.  It is imperative that you rub the excess wood grain filler from the parts, otherwise it will take some serious sanding to remove it when it dries.  Last three (3) pixs with the neck and Reso polished with steel wool.  The resonator could use another application of filler but don't plan to do it.  Sequence pixs below:

  

Note:  The above peghead is much lighter than depicted in the pix

I wasn't impressed with my application of the paste wood grain filler especially on the resonator.  I attribute that to myself not having used any paste wood filler for decades and my learning curve was not up to speed either.  The 0000 steel wool might have been a very bad idea since it could easily have pulled the wood grain filler from the pores.  The wash coat of sealer that I used over the stain was still "slick as glass" after I sanded it down and that could have had some bearing on the filler not staying in the wood pores.  I also did another error by thinning the product with Acetone instead of Naphtha or Mineral Spirits per the manufacturer's recommendations.  The Acetone is the fastest drying of the three products mentioned above with the mineral sprits being slowest drying of the three.  The acetone did dry the paste wood filler out far too fast and I didn't realize the mistake until after the fact.  I simply didn't look at the label on the container as "brain dead" as that sounds; both the Naphtha and Acetone container had nearly the same color scheme; still no excuse......ok go ahead and grin because I am for sure!  The Acetone should have cut into the sanding sealer some by being in the wood grain filler but it did not have any effect on it.  Very little of the paste wood filler stayed into the pores of the resonator back and will have to make up for it with additional top coats to get a smooth level finish.  I simply had enough of the paste wood grain filler and back in the early 1970s did a custom one piece Brazilian rosewood hearts and flowers neck for a tube and plate pot assembly and did not use any wood filler and it came out fantastic.  I still have the letter of appreciation on file from a very satisfied customer or it could have been his Dad.  

The resonator and neck were lightly sanded and buffed with 0000 steel wool and allowed to cure a couple days to make sure it was totally dry and no bleed through into the stain was noticed or white discoloring as has been attributed to some mahogany wood. 

SCRAPING THE RESONATOR AND NECK BINDING

Prior to spraying a coat of sanding sealer on the neck and resonator, I decided to scrape the binding to remove the color from the aniline dye stain and the wood filler staining.  It would be scary to know how many miles of binding THE GREAT DEPRESSION ERA Gibson craftsmen scraped over the years.  I tried to find my favorite tool that I used to scrap the binding from the neck and resonator side walls which was an ole Case XXX multiple blade pocket knife and used the "Sheep Shank" shaped blade which worked very well for me.    I could not locate said knife so used a single edge razor blade and a small round pointed utility knife for the rings in the back of the resonator.  One needs to get comfortable and take your time because scraping the binding is quite boring and it is easy to make a slip so attention to detail is required.  I got out the Opti-Visor for this job which really helped see the edge of the binding against the wood.  I could not get a good pix of the actual process because I need to access the camera shutter button on the right side of the camera, therefore I had to hold the razor blade and utility knife in my left hand of which I use my right hand for this task.  The forefinger is used as a guide and limits the length of the razor blade contacting the binding and I normally scrape the binding from my right to the left and the razor blade or knife is positioned about 10 degrees toward myself and not held vertical at a 90 degree angle, otherwise it will skip and make a sound like chalk scraping on a slate chalk board.  Also, a small rag or towel was used under my right hand to protect the resonator from my fingernails since while scraping the resonator rings, the small utility knife is held more or less like you would hold a pencil or pen and the left hand aids in controlling the movement on the resonator rings.  While scraping the binding from the resonator sidewalls, I held the resonator about vertical controlling it with my left hand and did the scraping with my right hand.  You can take an inch or more in length scrapes and once you get the technique down, you become much faster with more confidence that you will not scrape into the wood removing any stain.  After a few inches of binding being scraped, the technique started coming back and I got a little more aggressive scraping the binding.  If you have any doubts about bleed through from the stain or paste wood filler, I would recommend spraying the sanding sealer over the paste wood filler and then scrape the binding since some finishes tend to bleed through with the first coat of sealer or top coat of finish.   Scraping the neck binding is pretty much "freehand style" since the frets create a bump in your gauging, however you could place a thin piece of sheet metal on top of the fingerboard but didn't see a need for that.  A few pixs below:

This pix shows how much the stain and filler colored the binding!

I sprayed another coat of the sanding sealer on the neck and the resonator after scraping the binding per the manufacturer's recommendation using the little DeVILBISS EGA 502 spray gun, however the 1.0MM tip was a little small for the sealer without thinning it.  The sealer sprayed much better with the Lynx L-300H spray gun with the 1.3MM tip plus being pressure feed and might have to go with it for the top coats.  The sealer will be allowed to dry a few days to a week depending on the weather and will  go over the resonator and neck lightly with 320 grit or higher dry sandpaper and then start the application of the top coats.  I believe I finally have all the white primer gunk removed from my spray guns from usage a few years ago.  Many Craftsmen today apply many thinned coats of sanding sealer for a build up and sand down with 320 grit paper before starting the application of the top coats, however old habits are hard to break!

Seems like the finishing part of this project is beginning to be a nightmare with the weather not cooperating with intermittent high humidity.  After spraying the neck with the sanding sealer, a quick shower blew in and it didn't take too long before the dreaded blush appeared underneath the sealer and halted the rest of the spraying for the day.  I didn't have any lacquer retarder on hand and hopefully the blush will dry out some of which it didn't and had to do a good sanding back through the layer of sealer which took the edge off the fun element of this project.  To add insult to injury, I knocked over the glass 8 ounce feed cup for the Devilbiss EGA 502 touch up spray gun shattering it into many pieces on the concrete floor and will have to round up a replacement of which the glass one has been replaced with a plastic one from the manufacturer now.   I have owned two of the EGA 502 spray guns and that is the first glass feed cup that I have broken...Murphy's Law Never Sleeps!

I contacted a few instrument builders that have sprayed this product and they recommended cutting it about 25 percent or more and doing the same thing for the nitrocellulose instrument lacquer.  In the mean time, I ordered some blush remover which is basically lacquer retarder and a mixture of thinner which cuts into the top coat melting it and slows down the evaporation process allowing the trapped moisture to escape; at least that is the intended plan anyway.  I might be a "blue fin sucker" on this one!  I think I am ok with the fine sanding and steel wool getting rid of the blush from the neck.  I will definitely order lacquer retarder and keep some on hand for my other lacquer spraying projects.   The best prevention for blush is not to spray when the dew point is less than 20 degrees from the temperature or the relative humidity is above 65 percent and keep your compressor tank and lines as free of moisture as possible.

I received a 13 oz. spray can of Jet Spray Blush Eraser product code B101-0871 manufactured by Behlen available from StewMac and applied a thin coat to the neck and it did the trick although I removed most of the blush with fine sandpaper and delicately and lightly sanded the curved parts of the peghead not wanting to cut into the wood removing any filler and/or stain.  A thousand dollars or more is not a bad price to pay for a 5-string neck after all....grin if you must!

LACQUER TOP COAT APPLICATIONS

My friend Harold Chriscoe of Seagrove, NC was very correct in saying that some of the new finishing products; filler, sealer and lacquer are different from the stuff that we used back in the early to late 1970s and the finishing techniques have changed to shading and coloring components mixed in the lacquer instead of the older aniline dyes and stains that I grew up on and my learning curve is much slower now than it was back in 1970s when I was around 24 years in age.  Duplicating the post war Gibson finishes such as the RB800 with the red sunburst was all done with mixed colored lacquer but I guess I am still old school  at heart.......no disrespect intended to us Senior Citizens....grin again if you have to!  It didn't take but a few applications of the sealer/lacquer sprayed onto the resonator to realize that sitting the resonator on top of an empty coffee can without a way to rotate the resonator easily is a bummer for sure.  Jennifer Johnson's plants on wheels inspired this rotating fixture.

To hopefully make it easier to spray the resonator, I picked up a cheap 6 dollar carrousel from Wal-Mart in their home and garden center that has a simple base with four pivoting wheels used for moving around heavy potted plants and figured it would surely work for this project.  I had some scrap mahogany 4 x 4, 3/4 inch plywood and a length of 1/2 inch diameter maple wooden dowel and that should be all the materials  needed with the addition of a few wood screws and glue.  Pixs below:

To rig this rotating fixture, I cut two (2) pieces of 3/4 inch thick plywood to 12 1/2 inches square for use as the base plate and upper platen support for the resonator since I want the fixture portable.  I then drilled a 1/2 inch diameter hole in the center of the one of the the plywood squares all the way through and glued a tight fitting 1/2 inch diameter maple dowel in place leaving enough exposed to engage the four wheel carrousel base of which I drilled a matching centered hole in the carrousel slightly oversize to allow it to rotate freely around the maple dowel.  I then cut a piece of scrap 4x4 square mahogany stock to 8 inches in length for the pedestal for the upper platen to retain the resonator.  I used the band saw with a piece of wood that had a 1/4 inch diameter hole drilled about 6 1/4 inches from the band saw blade to pivot the 12 1/2 inch square upper wooden platen for the resonator rendering an accurate circle.  The parts are held in place with flat head Phillips wood screws about 1.5 inches in length with the heads countersunk.

The length of the pedestal can be shortened or lengthened depending on the height of the table or equipment you plan to place it on top of for usage.  This spraying fixture worked great clamped to the top of my router table and didn't have but 6 bucks cash outlay since I already had the other materials laying around needing usage anyway.  I held the spray gun the correct distance from the resonator side wall and rotated the fixture and kept the spray gun in the same parallel orientation to the resonator outside side wall and rotated the base of the carrousel the proper speed to get an event coat of lacquer.  I then quickly sprayed the back of the resonator and lay on a good wet coat of the lacquer that was thinned about 50/50 to help fill in the open pores of the mahogany that wasn't properly filled to begin with. 

I plan to spray at least six coats, about 3 coats a day about 2 to 3 hours apart and let dry a week or more and wet sand to level the finish and go from there.  It will probably take another 5 or 6 sets of 3 coats a day to get a good build up of lacquer ready for final wet sanding, polishing and/or buffing out the finish.

After a few days of curing, I "drop filled" several places on the peghead, resonator and wood rim that had very low places that had absorbed the lacquer and well below the coats of lacquer.  I used a small brush and also toothpicks to apply a small drop or two of lacquer to those areas and will sand them flush with the regular finish with a small strip of 320 grit free-cut sandpaper prior to water sanding.

I do not plan to add a tremendous amount of lacquer to the wood rim of which I feel too much finish actually inhibits the wood rim to promulgate vibrations transferred from the neck, head and tone ring just like too much finish on a guitar top is a bad thing as well even though the wood rim doesn't vibrate or move air in the same method and fashion as a guitar top does but it does transfer energy from the vibrating strings back to the banjo head helping augment the amplification, timbre and sustain process.  I formulate a PC analogy as:  "The wood rim being the "motherboard" which controls all the pherpherphical components such as the tone ring, neck, strings, head, tension hoop, bridge, tailpiece, hook & nuts, resonator, etc. to produce the volume, sustain and timbre one desires!"  

The Great Depression Era banjos didn't have the heavy build up of lacquer on the wood rim as post war banjos do especially the resonator models since very little of the wood rim is seen anyway and is really counter productive once the wood rim is sealed.  Whether or not the wood rim is allowed to "breathe" naturally with the changing levels of humidity in the air or a means of controlling said wood rim expansion and contraction by synthetic means, I have never ventured heavily into that area of experimentation and do not have any conclusive evidence to support or deny such claims.  Gibson has changed their finishing techniques over the decades and I still favor the ole hand stained finishes such as the sunburst and other finishes mimicking the 17th century violin finishes. 

Pix below of drop filled areas on the resonator back adjacent the inner most white/black/white ring along with dust that has settled on the back as well of which can be vacuumed or air blow away.  Note:  No wet level sanding has been done yet on the resonator and will be the next step in a few days and will commence with the build up of top coats of lacquer about three or four coats spaced about three hours apart and will wet sand at the duration of each three to four sets of top coats applied.  You can  see the darker paste wood filler that adhered to open pores in the mahogany back veneer panel which adds contrast.

  

WET SANDING

With a good build up of lacquer top coats around nine (9) coats of which the first six (6) were sprayed on very thin about a 50/50 mix or one to one of lacquer to thinner ratio even though the manufacturer stated it could be sprayed on without reducing, however without ideal conditions, the thinned lacquer was the way to go in my case although retarder added is more fail safe to reduce the evaporation rate of the solvents in the lacquer but will increase the drying time.  Since I failed to properly fill the pores of the resonator and neck, the thinned lacquer was necessary although you don't build up finish as quickly.

I am using 3M 213Q Imperial wet or dry Production Paper P320 grit available at Wal-Mart locations,  most hardware stores and Automotive centers and allowed the paper to sit in plain tap water, preferably overnight and a clean cotton towel to dry the areas wet sanded to check on the progress of the wet sanding and keep the thin white slurry produced wiped off the parts.  The P320 grit is the European grade designated with the letter P in front of the grit size.  The P320 paper is about the same grit as a 280 USA grade paper which is more or less for dry sanding only.  I had a good build up of lacquer due to the need since the wood grain pores were not properly filled, I wanted to cut the top coats down pretty fast and used the P320 size paper, however under normal circumstances I would have used a 400 grit in the USA or CAMI grading system or started with the P600 or P800 European P-grade wet/dry paper.  I believe the European graded paper has a more uniform grain size and does cut more aggressively. 

This first wet sanding is to try and level the build up of top coats of lacquer to a smooth even finish to remove the bumps, dust fuzz, nubs and orange peel type finish.  It is imperative that you keep the part being wet sanded coated with plenty of water since this keeps the pores of the sand paper open and allows the sand paper to cut evenly into the finish without dragging any of the finish.  You can add dish a drop or two of dish washing liquid to the water to increase the lubrication factor of the water, but I never have used an additive although many do and there are products commercially available for this specific purpose.  Dip the paper into the water often and remove the slurry generated by cutting the lacquer top coats.

While wet sanding the edges and curves of the peghead and neck, great caution must be exercised not to sand through the finish into the stain and/or filled areas which will require touch up which you definitely want to avoid.  It is best not to try and sand the finish down completely level the first wet sanding time around since it will require four or five more three or four top coat applications and wet sanding to get a thick enough finish of top coats of lacquer build up prior to the final polishing and buffing the parts for a piano type mirror finish. 

After wet sanding a small area, immediately dry the area off with the towel and inspect the finish tilting the part toward a light source to allow you to properly see the areas that are still below the level of the finish which will appear as bright shiny spots.  To reiterate, "wet sand with caution" since you don't want to cut through the finish into the filled and stained wood.  The pix above on the lower left of the back of the peghead shows the shiny areas that are below the level of the finish and also on the neck portion next to the hand volute or hand stop you can see the bright shiny spots that are the pores of the wood that are below the level of the finish that has been water sanded down.  You can also see the edges of the peghead which I left alone since that is the main area that is the easiest to sand through into the finish because the lacquer build up is thinner on the edges and more prone to cutting through into the stained/filled wood.

On the flat portions to be wet sanded, you can use a small block of wood with radius edges,  large flat rubber eraser,  piece of cork, sponge backing or hard rubber pad but I prefer to use the flat portion of my first three fingers to gently guide the paper over the areas in a circular motion.  I did not cut the finish down to completely level but after each build up coats of three or more, the finish will be leveled up more each time and will increase the wet/dry paper size at the end of each three to six coats of top coat with 400, 600 and 800 USA CAMI grade wet/dry paper and hopefully will not cut through the finish into the filler and stain.  After the parts were wet sanded,  a clean wet cotton towel was used to remove any remaining slurry and prepare the parts for another series of top coat applications, however the weather at the moment has too high humidity and with archery deer hunting season coming in yesterday, I will apply coats of top lacquer when I can "squeeze" it into my busy work and hunting schedule.

A good comfortable chair is also required since this is time consuming and those experienced will wet sand more aggressively than I am doing on this project due to the fact it has been ten (10) years since building any kind of instrument and more than 32 years for a banjo.

WOOD RIM    

While waiting for the neck and resonator finish to cure a while before wet sanding and laying down several more top coats of lacquer, I decided to finish up the wood rim finish.  As I stated earlier, I do not want a heavy build up of lacquer on the wood rim and dry sanded the wood rim using 3M 216U Production RN Paper A wt. Open Coat Fre-Cut in grit size P320 available from StewMac and leveled the finish which didn't take very long.  I did not wet sand since I want a satin finish and polished the wood rim with nothing but 0000 steel wool and buffing by hand using a cotton towel without any rubbing compound or polish.  I cut what little finish there was on the top edge of the wood rim that supports the tone ring "lip" and the side portion that makes contact with the "skirt" of the tone ring.  My nomenclature is probably not standard describing the tone ring but it should be in the "ball park".  Before going too much further with the wood rim, I will fit the tone ring and if there is too much build up of finish on the side, I will sand it down for a proper fit which can vary from loose to tight depending on what school of thought and your own personal preference biased by what timbre you desire or "hope" to achieve.  Pix below:

  

NECK AND RESONATOR

After spraying six (6) or more top coats of a 50/50 ratio of lacquer to thinner over the course of a few days and letting dry about a week, I wet sanded the neck and resonator with 3M 413Q 600 WetorDry Tri-M-ite Paper A wt and both parts leveled out very well.  A few pixs below:

On the flat portion of the peghead, I used a rectangular shaped eraser as a backing for the wet sanding and it was the perfect size.  I wet sanded the sides of the peghead with the paper carefully with only the tip of my forefinger as the backing means.  I used a small piece of sponge as the backing for the paper for the resonator side wall and the back.

I will spray another six (6) coats of 50/50 lacquer to thinner over a two or three day period and should have enough finish built up for the final wet sanding with 800 grit Tri-M-ite sanding paper.  I will let the finish cure for a week or two before doing the final wet sanding and polishing, etc.  Since I do not have a time line for this project, time is not of the essence.

Ole Murphy's Law came out of retirement again and my Lynx spray gun started throwing "globs" of lacquer out while I was right in the middle of the first coat or two of the final top coats for the resonator and had to stop in the middle of spraying the back of the resonator and try and salvage the mess.  The next morning, I scuff sanded the resonator back with 3M 320 grit free-cut paper and leveled the "globs" of lacquer to the surface and continued the build up of top coats of lacquer for the resonator and neck.

The neck looked so good with the final three thinned top coats of the lacquer it will be hard to make myself wet sand it down with 800 or 1000 grit wetordry paper but I will do it; well maybe not!

BUFFING AND POLISHING

I have reached a cross roads as to which direction to take since basically I no longer have any serious buffing equipment such as a pedestal buffer, buffing wheels and the appropriate buffing compounds or adequate buffing pads for my random orbital variable speed sander/polisher.  To get a factory mirror/glass finish, it is imperative that you buff the finish after the final wet sanding operation to obtain that "piano" type mirror finish .  I have hand buffed and polished banjo components in the late 1960s but that requires a tremendous amount of elbow grease and time and it still takes a back seat to a properly machine buffed and polished instrument.   Since a buffing arbor is a fairly expensive piece of equipment, especially one large enough to do a guitar or banjo resonator and the price varies as to the quality, I decided to go on the low to medium side cost wise and opted for a 3/4 inch diameter shaft buffing arbor and will use my own motor and home made portable platform to mount it on.  If I were in the Musical Instrument business  I would not hesitate to purchase the complete buffing arbor offered by StewMac.

By the time the lacquer has dried a few weeks on the neck and resonator, I should have the buffing arbor, buffing wheels and compound in and test driven before attempting the buffing and polishing the neck and resonator.  I will take a few pixs along when the buffing arbor arrives and start putting it together.

I received a Shop Fox Model W1681 Buffing Assembly (arbor) from an internet company and I have used the ole saying "Normally you get what you pay for" and this is a very good example of it being true for sure!  With shipping it was a little over  $126 bucks and figured it should do well enough for no more than I plan to use it; certainly not for any type of continued usage.  The shipping weight was advertised at 30 lbs. and thought it would be adequate but in reality the shipping weight was only 14 lbs., therefore the housing for the shaft had to be light weight and that it is....made out of 3/16 cast aluminum and the bearings don't look that large either.  I also received some buffing wheels from Stewart MacDonald along with buffing compounds and they are first class as is most of Stew Mac's products.  Pix below;

 

The buffing assembly comes with a stepped 3, 2 and 1 inch diameter V groove pulley and the recommend rpm for the shaft with a 10 or 12 inch buffing wheel is somewhere between 800 to 1000 rpm.  I checked the only spare motor suitable and it was 3HP but running at 3450 rpm and 115/230 volts single phase and will have to round up something in 1725 rpm since I can't get a small enough pulley on the motor shaft due to it's size...the motor is a Baldor on a metal chop saw which has never seen any usage as it was a spare or back-up when I manufactured metal climbing hunter's tree stands.  The Baldor motor is certainly old school and weights a "ton" as compared to the new lighter motors.  I could use a couple step pulleys to get the rpm correct but I don't want to have a Rube Goldberg looking portable rig that I plan to store in a corner or on the basement shop wall, etc.

Hopefully, I have misjudged the buffing assembly even though it did not meet my initial expectations; guess I like the more heavier industrial stuff better.  If the shaft runs true without a lot of vibration, then it will serve the purpose. 

I will put a few feelers out and try and find a used 1/2 hp 1725 rpm motor for 115VAC.

I have the banjo project on hold since the weather has gotten cooler and smitten by the archery hunting bug and with a couple deer already tagged, plan to fill the freezer between now and the first of the year using archery equipment, .50 cal. muzzle loader, .44 cal.  Mag. pistol and 270 cal. rifle.

Bill aka Mickey Porter 10-10-10.

With a full moon last night 10-22-10, I decided to forgo deer hunting today since deer normally feed all night and then come out again in the middle of the day and will be a good time to get the buffing assembly (arbor) mounted onto a base board and get it operational.  I purchased a used 1/2 hp 1725 rpm motor off EBay and my friend Joe Estridge at Estridge Lock and Key  gave me some electrical parts, power cord, switch, switch housing, etc. and only had to purchase a small pulley for the motor and a metal cover to match the switch box housing.  Pixs below:

After getting the parts mounted onto a 3/4 inch thick piece of plywood as a base plate, I was surprised at how smooth it ran.  The 1/2 hp motor had a little vibration to it but the buffing arbor ran very true.  I positioned the motor bracket base holes in the plywood to allow some adjustment for the belt.  It was difficult to  position the motor with the correct belt tension due to the 1/2 inch width V belt being very stiff and was coiled up around the buffing arbor pulley and did not want to relinquish the memory that had taken place since manufacture, package, storage and shipping.  I used some "horse engineering" by clamping the motor down with a couple C clamps and used a couple blocks of wood and a tapered wedge and drove the wedge into position to get tension onto the belt and marked and base plate and drilled the bolt holes.   After breaking in the 12 inch diameter StewMac buffing wheels, I looked as if I worked in a cotton mill with all the lent, etc. from the new buffing wheels all over my person and the floor.  I used a 1.5 inch diameter motor pulley and might have to go to a 2 inch diameter pulley to increase the speed a little.  I loaded the left buffing wheels with Extra Fine and the right with Fine Menzerna compound since I plan to wet sand the neck and resonator with 1000 grit wetordry paper.  It has been one month since I applied the final top coats of lacquer and I believe the lacquer shrinkage has maxed out and will final wet sand, buff and polish the neck and resonator very soon.

On 10-24-10, I completed the final wet sanding for the neck and resonator using 1000 grit wetordry 3M paper.  My favorite auto parts store did not have any 800 grit in stock so it took a little longer with the 1000 grit due to the shrinkage on the resonator since I applied a few final top coats heavier than normal.  Below a few pixs with the buffing arbor in usage:

A few observations on the "jerry rigged" buffing arbor; I believe the arbor shaft speed is too slow and also the 1/2 hp motor is under powered using the 12 inch diameter two inch width cotton buffing wheels; using two (2) that are 1 inch in width.  It was difficult to get the Menzerna compound to properly melt onto the buffing wheel as it should because of the lower surface feet per minute (SFPM) of the buffing wheel and the 1/2 hp motor would slow down very quickly if much pressure was applied to the wheel from the part being buffed and/or buffing compound.  I will change the 1.5 inch diameter motor pulley to 2 inches and see if that helps any and be on the lookout for at least a 1HP 1725 rpm 115VAC motor.  It could very well be the used motor I am using is also on its last leg too....grin on that one!

The pix to the right is a comparison of the neck that was wet sanded and no buffing has taken place yet.  I believe the finish is going to come out fine even with all the set-backs and mishaps that has occurred during the finishing stage of this banjo and no ones fault but my own due to my prior experience remaining dormant for decades.

After buffing the neck, I will start getting the neck ready for attachment to the pot assembly which will include cleaning up the fingerboard, installing the tuners, 5th string peg and re-checking the fret work, etc. and cutting/filing the nut string slots and getting the proper action.  This banjo project  will probably be on the "back burner" since it is getting close to our Central North Carolina section annual deer rut and plan to be out and about a couple weeks next month filling my freezers.

 NOTE:  On 10-25-10 I replaced the 1.5 inch diameter motor pulley to 2 inches diameter and the increased SFPM  worked like a champ.  It was much easier to apply the buffing compounds to the wheels and the motor did not bog down when applying pressure from the buffing compound applications and the actual buffing of the parts.  It didn't take but a minute or two to complete the buffing out of the neck and resonator and very pleased with the results.  I did change to the medium and fine Menzerna compounds instead of the Extra fine and Fine and both parts buffed out to a mirror finish!  Surface feet per minute is figured by dividing the wheel diameter by a factor of 4 and then multiplying that by the shaft revolutions per minute (rpm).  Many commercial finishing outfits recommend a surface feet per minute (SFPM) between 3500 and 7500 depending on the material you are polishing and buffing.  This motor to arbor ratio of 2/3 gave me 1150 arbor rpm which equated to 3450 SFPM for the 12 inch diameter buffing wheels.

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