Guitar of the Month - November

November 02, 2016

Since our luthier community are some of the most passionate individuals whom we have met, we decided to highlight one guitar project per month, and feature it on our blog.  In order to be featured, one must showcase the guitar they worked on, the Mohawk/Behlen products that were used, and a short story about why this guitar project is important to them.  From there, individuals from Mohawk will collaborate and announce a winner. When a winner is announced, we will reach out and begin writing about the project. Winners will receive Mohawk/Behlen guitar finishing items in order to congratulate them on a job well done. Find out more about our guitar products here: http://www.mohawkconsumerproducts.com/products/guitar/#Guitar Repair

This month's winner is Sam Eakins, and this is his story.

" Working towards perfection.  Cosmetic repair on this vintage Gibson.  One of the challenges with repairing vintage guitars is to fix what needs to be fixed and not hurt the collectible value of the instrument.  There are a lot of complicated points to be made on what establishes the value of a vintage instrument.  This guitar had some large gashes previously repaired and an attempt to cover the damage with something that was in the same color family but not right.  It was probably nail polish and actually magnified the repair.  It was like a food stain on a white shirt saying, 'HEY! Look at me!'

Overview of Guitar

This top is on a guitar that is loved and played in...years of writing songs and miles of gigs.  It's got patina and weather checking - it has a story.  So, we want to leave the mileage and make the obvious 'uglies' go away, or almost invisible.  First thing is to understand how the manufacturers applied the original finish.  I start the repair process by scraping away the discoloration and damaged finish.  I have years of experience doing this and have had benefit of some amazing teachers throughout my career.  Scraping down to clean wood then layering and building back is the way.  Clean wood tells the truth and the end result will be more natural looking.  I've tried to squeamish dab a little here and there and don't disturb the vintage finish monster or he will eat you alive, lol.  Or reality is it eats valuable time in the shop and still not look great.  Time is priceless when you have hundreds of guitars passing through annually that need to be fixed.

Once I've established a clean edge, I apply a thin coat of hide glue with a q-tip.  The hide glue is thinned with deionized water to the consistency of buttermilk - runny but not too runny.  Let it dry. This provides a barrier to protect the clean appearance of the wood.  If I started applying anything like CA glue or lacquer, it would discolor the wood unnactually and be splotchy.  This is also the same technique I use to repair cracks in under-humidified guitars.  You know, you get the guitar healthy and the crack closes up and when you finish the repair, you've got a fine dark line where the crack was.  This helps eliminate that cosmetic issue.  Next step is to raise the finish and add color as we go.  You can see in the picture how thick the mils of the finish are.  After the hide glue dries clean around the edge and start layering CA glue.  I use a couple of brands - not all glues are created equal. Do some research.  I use a medium thin viscosity (thicker than wick grade thinner than medium).  Now the trick on Cas - you can spread out your application then go eat a sandwich, or play solitaire.  Come and check and it may be set or not.  I know that the bottle says 10 seconds,  but that was in a lab applied in a specific measured amount in a controlled environment.  So grab the accelerator!  Squirt it on there, and boom, you got some smoke.  Now you got swirls of milk and the vintage finish next to the CA is melting! I use acceleration all the time and never have this problem. 

Damaged Guitar Collage

What type of accelerator you use is just as important as how it's applied.  When selecting an accelerator, in this case, I'm working with lacquer so I have to make sure that my kicker is not acetone based.  Acetone melts lacquer.  I've always used Zip Kicker; it does not have an acetone as a carrying agent.  The next thing is how it's applied.  I've never had consistent results with aerosols or pump spray bottles.  I use a badger airbrush with gravity feed bottle with adjustable flow needle.  I use a small PSI air compressor providing about 12 to 15 PSI with a simple moisture filter inline similar to the setup in the picture.  

Before I apply my initial layer of CA, I spray a light mist of Kicker to the repair area from about 10" away evenly.  Let it evaporate then apply CA medium or medium thin.  With the Kicker dry, but present, it will react but at a slower pace.  The result will be evenly cured CA without milking.  You will see it shrink slightly but that's fine you have more layers to go.  The next layer goes on and since the Kicker is still present in the first CA application, it will react but must slower so you have time to smooth it out.  Then you spray Kicker same as before on top of the 2nd layer, and you get an instant reaction. 

Guitar Collage - Sam

 Then, mixing and matching dye to get shading right.  I use lacquer thinner to mix with.  Then, I can just add the same measured amount in Behlen lacquer to start building the color so my mix is usually 50/50.  In this case, I'm matching aged cherry. The more layers of cherry added, then the darker it gets. Then I will add a drop of brown if needed as I go.  I use a soft brush and patience. Or a fine detail airbrush with low PSI.  Remember, I'm still many mils from a level finish.

Important lesson: I tape off just inside the edge of the original finish when you start building your color if you overlap or bleed onto the original finish, it will always create a dark outline. Sometimes it's unavoidable but this helps. Once we get close on our color, remove the tape and lock it down with a thin coat of clear.  By now, I'm only a couple of layers of CA to get level.  I usually build just passed the level of the original finish then use a razor blade to scrape it flush.

Then, wet sand with 800 to smooth it out.  Then I use a gravity feed detail spray gun (1.5 mm needle 30psi) with 50/50 Behlen and red mahogany dye in the mix to bring the edge of the burst in and do a blending wash around the bout of the guitar.

Once I get the blend the way I want, I lock it down with a few coats of Ultra Bond.  I like the option of "rattle cans" especially when it's a great quality product you can rely on.  I use rattle cans for convenience factor also.  If I've got my spray guns loaded with tinted product for other jobs, now I've got my color locked under a few coats of clear as a buffer.  I will scraped the binding clean again. You all are asking the question, "why didn't you mask the binding off?" Well ladies and gentlemen, my experience has been you take a good amount of time to do a detailed mask, and no matter how well I do and no matter what quality of tape I use, there is always bleed.  You will have to scrape the binding anyway, so I eliminated that step.  I do mask all other portions of the guitar that should be protected from over-spray.  Then, wet sand with 800, 1000, 2000 and then a diamond dust 3000 grit pad (3M products used in auto body repair.)

Then with guitar in hand, I go dance with Buff Bagwell.

 Pickups and Frets - Guitar Collage

I use two different buffing grits; medium and fine (Menzerna polish bricks).  Since this is new lacquer, I use lower speed and go straight to fine grit.  On fresh lacquer, I like to use the 3000 diamond dust wet sand pad (as I mentioned earlier) in place of the medium grit buffing step.  I have more control on the take away aspect of the new finish.  Then the fine buff is quick constant motion with lighter contact on the wheel. Lower speed and keep moving with lacquer, not trying to generate heat.  If this were a poly finish I would use slower movement and higher buffer speeds because you want to heat the poly up to get a proper shine.  

With repairs like this, you will see a degree of the finish anomaly. The standard is to achieve the highest level of invisibility you can without making the finish look out of place. The customer did want the top refreshed and buffed "shiny" but leave the mileage.  Literally stripping the finish off of the entire top and duplicating the original burst I think would be easier, but then you erase the guitar's history."

Sam Eakins Guitar Collage

If you would like to be considered for our Guitar of the Month for December, submit your before and after photos on our Facebook page, or tag us on Instagram.  

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