HG Thor Guitar Lab – Epoxy Fretless Fingerboard Technique

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HG Thor Fretless Conversion Fender Precision Fretless Bass


HG Thor Fretless Conversion Fender Precision Fretless Bass
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Forward by Eric Larson, Founder of

I have a weakness for 1970’s Fender Precision fretless basses with the one-piece maple neck and unlined fingerboard. I own three of them and they all have their own personalities.

One particular Fender I bought on eBay was not in the best condition when it arrived at my home.  It had a rust brown stain applied over the original natural body, and the fingerboard had nicks, chips and dead spots in various locations. The finish was worn and it just didn’t have the life that I knew it once had. I had read about Jaco’s epoxy fingerboard finish technique and always dreamed of having a fretless with that hard glossy treatment. Harris at HG Thor Guitar Lab, expert in this process, brought new life to this bass and I couldn’t be happier with the results.

He was thorough, professional, gave me regular progress

updates complete with digital photos, and went the extra mile overall. Not only did he do the neck, but he did a complete overhaul on the body bringing it back to its beautiful natural state, cleaned up the electronics and did a complete setup before shipping me back the bass.

HG Thor Fretless Conversion Fender Precision Fretless Bass
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HG Thor Fretless Conversion Fender Precision Fretless Bass
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This bass sings – the fingerboard is absolutely amazing. The sustain and growl from the round wounds at any point on the entire fingerboard are impressive. “Mwah” just oozes from this bass. The action is super low, which is a nice difference from my other basses. It doesn’t just sound good, it is a work of art. Harris put many hours into this bass which will translate into many years of enjoyment for me. I highly recommend the services of HG Thor Guitar Lab – it is well worth the wait! Go to the HG Thor Guitar Lab epoxy page for more info.

-Eric Larson

HG Thor Fretless Conversion Fender Precision Fretless Bass
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HG Thor Fretless Conversion Fender Precision Fretless Bass
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HG Thor Fretless Conversion Fender Precision Fretless Bass
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HG Thor Fretless Conversion Fender Precision Fretless Bass
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HG Thor Fretless Conversion Fender Precision Fretless Bass
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History of the HG Thor Epoxy Technique by HG Thor:
Some may find it surprising that I am a guitarist first and foremost. In fact, the bass has taken a back seat in my music listening during my formative years, with notable exceptions Jack Bruce (Cream -Wheels of Fire, my initiation), Stanley Clarke, Slam Stewart (a local personality) among others. I am originally from upstate NY, but one of my close friends, Armen Boyajian, invited me down to Washington, D.C. in 1978 to explore the culture and I ended up staying a couple years renovating brownstones. Armen was a gigging jazz violinist/pianist, playing with young local musicians such as Ed Howard (bass), Steve Williams (drums), Paul Bollenback (guitar) and appearing with Wallace Roney (trumpet). It was Armen who first introduced me to Jaco Pastorius via Weather Report’s Heavy Weather and Joni Mitchell. Absolutely turned my ear on end and the Jaco bug thus bit me.

I returned to upstate NY in 1980 in pursuit of home remodeling and college, but remained active as a musician. A friend, bassist Eric Sunness, loaned me a late 70’s Bass Player issue featuring an interview with Jaco. In it was his description of how he first defretted and epoxied his Fender Jazz bass. I acquired a 70’s Kay SG shaped bass from a local music store fire sale. Inspired by Jaco’s descriptions, I pried the frets out with a butter knife and filled the slots with wood putty, but the epoxy part I found was a bit more complicated. Petit’s Polypoxy as mentioned in the Jaco article was not to be found. I experimented with many different kinds of epoxy. It seemed to brush on fine with a bristle paintbrush using masking tape on the sides. I recall filing it down with a big mill file, which kept getting clogged up. Despite notes that buzzed, the bridge being a single piece of bent steel, a pickup that behaved more like a microphone, the neck dipping down unless you held it up, the darn thing played and sounded rather fine. I made a custom case for it and it is featured on many of my early 80’s recordings. A reminder of my humble beginnings, it stays here in the shop – the original epoxy mod still going strong!

In 1989 I obtained a DBA and retail sales license for a guitar and amp repair business. The 1990’s were very musical for me, being in many bands both cover and original, and building up a business as local repair guy for instruments and electronics. Basses were usually of the fretted kind, but I received one on occasion for defretting and epoxy. I began to develop my own playing skills on the fretless bass. This led to more fretless epoxy mods. Methods were discovered to eliminate defret chipout, inlay fretlines, and work the epoxy to a uniform and attractive surface.

Reaching out on the web:
Going cyberspace in 1997 allowed my HG Thor Guitar Lab to reach out to a vast and growing community of fretless bassists. My first international fretless epoxy bass mod was in 1999 for an American player stationed in Naples, Italy on a Warwick Thumb bass. In January of 2003, Xavier Padilla, then bassist for the Gipsy Kings, had contacted me about making his Fender signature Jaco bass serviceable and adding my epoxy mod. I returned his neck with a leveled, re-radiused fretboard and epoxy. It is a matter of public record how he has greatly enjoyed it, and I owe him many thanks for helping to promote my positive image on the net. The background tune on his new website, St. Thomas, is played on this bass, and can also be found on my epoxy fretless sounds page. It is apparent he is a tremendously knowledgeable and talented musician in addition to being multi-lingual. Yet Xavier is very approachable and friendship has come easy. I have the honor of being involved in an aspect of Xavier’s radical custom Torzal twisted neck bass as built by Jerome Little of Texas, specifically the magnetic pickups designed by my good friend Chuck Burge as conceptualized by myself and built by Chuck in his fantastic Kalamazoo shop. I also customized the preamp system the pickups operate through. Jerome installed everything so it has been one remarkable collaborative effort that has taken place in 4 different parts of the globe! You can hear Xavier’s Torzal Little bass on both You Tube, and his Myspace site. No doubt there will be much more to hear from Xavier and both his custom bass and the epoxy fretless in the near future. I have had the privilege to perform the epoxy conversion process for several other very talented high profile players. Some of their comments may be read on my Testimonials page, and I thank them one and all for their generous gift of words and friendship.

The epoxy process:
I often get asked what kind of epoxy I use and how to apply it etc., but I have been reluctant to discuss that. This is not unusual. Many builders have their trade secrets. But I would be glad to talk about other aspects of my process. For example, often a new board will require resurfacing to correct linearity issues, as well as any string grooving. There is minimal chipout on fretted necks. Fretline choices are made and installed. I do use at least two coats of epoxy. One to provide a good foundation and a second to create a smooth consistent top layer. I keep a close eye on the fingerboard as the final surface is worked, to ensure it will be perfectly linear within the existing radius. Any imperfection at this stage will cause localized buzzing when set up for close action. The epoxy wraps around the sides of the fingerboard to a certain degree and is dressed carefully to be unobtrusive. This helps to ensure a seal between the old finish and the new epoxy which adds strength and minimizes effects caused by environmental changes. I am most impressed with bone for nuts and create them from scratch, observing construction techniques of old school craftsmen as well as new string spacing geometry. I offer inlay repair and new installations. Side markings can come in different shapes colors and sizes. Choices for pickups and electronics are available. I am happy to work with customer ideas within the bounds of possibility.

Why epoxy on a fretless bass?
According to interviews with Jaco, he used it to prevent wear on the famed already fretless $90 1962 Fender Jazz bass. I understand Jaco’s epoxy began to peel off and around 1978 Kevin Kaufman of Kaufman-Daenzer Instruments gave it a poured on treatment and filed it down with a rasp (Bill Milkowski: August ’84 Guitar Player; January 2002 issue of Bass Player, CMP Information Inc., “Jaco’s Gear Through the Years” By E.E. Bradman & Scott Shiraki). My product today is applied and worked much differently, and is recognized to have many notable qualities. Xavier Padilla’s analysis is: “…everything is brighter and all details come out clearer”, and “…with epoxy coats on the fingerboard a fretless electric bass still gets a woody sound, but with a new element that brings it closer to that of a grand piano.” The full quote can be read on the main Epoxy Fretless page along with more of Xavier’s quotes in Testimonials. Perhaps much of this can be attributed to the fact that my coating is just thick enough to prevent wear, but still allow the neck wood to resonate naturally. An increase in sustain is evident, due largely to greatly reduced friction formerly resulting from the strings contacting the softer fingerboard wood. The result is many more partials alive along the string length as controlled by right hand technique and dialed in with the tone knob for that singing vocal “mwah” quality. Bringing all these elements together with a carefully dressed and linear fingerboard surface yields a beautiful and inspiring instrument to play. I have epoxied many different kinds of rosewood, ebony, maple, wenge, and even phenolics, all with excellent long lasting results.

Service with no surprises:
A typical transaction will start out with my evaluating the bass and communicating via email with photos of each area of concern. We discuss options for fretlines, color or stains if any, repairs to damaged areas, nut, inlay and/or markers, options for mods, hardware and electronics. A photo is sent to show what the fretboard looks like under the first coat of epoxy, which is often surprisingly deep in contrast bringing out never before seen grain detail and color especially on rosewoods. Each customer receives a final email summary and billing which includes my observations of the final result, photos, all charges and options for payment. The neck is wrapped with protective film and an invoice with the instrument’s serial number and my signature included.

It appears I have some kind of cult status as fretless epoxy guru on the net. Feels odd, like a vicarious experience really. I’m very honored by the compliments, but also realize this is entirely a function of doing consistent top quality work and going that extra mile to make every customer happy. For years now I have been forced to place bassists on a waiting list. This is not the way I like it to be, and am doing my best to find ways to reduce turn around time without sacrificing quality. Each individual epoxy mod is hand done using specialized tooling and a long acquired skill set gleaned from the crafting experience. The process has become a series of complicated steps, many of which are challenging for me let alone an assistant. Assuming I could find and hire an assistant with the talent required, I suspect by the time they would be trained they would be off to pursue something else. Frankly I enjoy working alone here in my upstate NY shop, living with my loving family and beautiful woods to walk in. Mods are always fun, but I have also been working on some new designs for basses, guitars and sound gear.


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