Harmony TG1201 Restoration attempt by a neophyte

[Underwood]

Hi,

A Harmony 1950-60(no serial number I could find) TG1201 Sovereign model tenor guitar was passed on to me, likely because I started playing guitar and I am a better woodworker than I am a player. The guitar is in rough shape, but for the most part just cosmetically with the exception of the bridge and a missing screw from the tuning machines. I will chronicle my restoration with the hope that people provide me suggestions on how to proceed as my skills up until this past month have been with finish carpentry and furniture repair/renovation/building.

I have provided a photo montage of the raw guitar and the stripped cleaned guitar. The guitar suffered from the following:

• Surface mold on the outside and body interior

• The guitar was strung with nylon strings, which is perhaps why the neck has a slight concave bow

• A screw (gear retention) is missing from one of the tuning machines

• The bridge is shattered

• The pickguard is unattached and has a slight bow

• There appears to be a crack (3") on the right lower lobe of the belly

• The finish is crackled

• A surface wear spot is located just below the 20th fret

• Some upper frets need a polish and or re-cut

I started by removing the guitar components and wiping the body down with white vinegar to remove the mold from the surface and where I can reach into the body. My wife promised she will give a second pass to the interior of the body as her hands are much smaller than mine. Afterwards, I wiped the guitar down with F1 fret oil as that is the only wood treatment I have on hand. The following day, I wiped the guitar down several times with MinWax hardwood floor cleaner. The guitar looks and smells much better. I have ordered a non-caustic mold killer/inhibitor (Concrobium) whose active ingredient is an enzyme derived from crab shells. I was worried about the mold problem stopping the project in its tracks, but the vinegar has taken care of the outside and some of the inside, and I hope the crab enzyme does the rest.

I could not find a screw to fit the tuning machines, so I ordered Grover Ukulele long machine tuners which, according to my measurements, should fit perfectly without any modification. I will try disassembling the Grover tuner gear/post and see if I can get it to fit the Harmony stock dual tuning machines, as I would like to keep the guitar as original as possible. If anyone knows where I can acquire a screw to fit the original tuners, I would be most grateful!

Next, I carefully removed what remained of the bridge and scraped the remaining glue with a razor blade. I have ordered an ebony flattop guitar bridge blank and Martin bleached bone saddle blank. I have reassembled the bridge such that I can reproduce it by oversizing the exterior dimensions 1/16th an inch laterally and probably 30% vertically in the area of the retention bolts as I have come to understand that the TG1201 bridges are prone to breakage.

The neck has a slight concave bow which I have not measured as of yet. I do not have the skills to attempt to correct a minor bow in a guitar neck which does not have a truss rod. I will attempt polishing the frets, but will not attempt fret levelling/cutting unless the guitar does not function properly, or rather I can detect a problem as a neophyte guitarist. As I become more proficient as a player/luthier I will likely attempt fretwork if it is necessary and I am able.

My intentions are to limit the re-finishing to the spruce top at this time. I intend to take a minimalist approach by attempting to remove the finish with lacquer thinner possibly beefed up with some acetone. Alternatively, I have had good experiences using a soybean-based non-toxic/non-caustic stripper. After stripping, I intend to apply either a thinned (really thinned) brushed on lacquer or a spray on (Rattle can) lacquer. I will be working in a garage which is approximately 60 degrees F and I have appropriate respiratory protection (organic vapor mask).

I do not know how to repair the wear spot below the 20th fret; the wear is slight, but I am hesitant to attempt to sand it out/smooth. I just want to get the guitar playable and have enough of a finish coat on that I can safely attach/maintain the bridge and pickguard. If my initial efforts are successful enough, I will revisit refinishing the guitar in a year or two.

If I may, I would appreciate suggestions for the bridge/pickguard glue. I can acquire Titebond Hide glue locally and use it for both the bridge and the pickguard, if that is advisable. I believe I can get away with using Elmer's white glue for the bridge as it is bolted on but am unsure if it would be sufficient for the pickguard, even if it is just for a year or two.

Thank you all in advance for following along, and I will post again after I receive the repair materials next week.

[Diane Kauffmds]

Unfortunately, there are many of these guitars, made in Chicago, by Harmony and other various brands, sitting around in this condition. Sovereigns were nice little guitars. I started out by restoring an old trashed 1950s Kay. It's a good way to learn about how guitars are built.

These guitars had steel reinforced necks. If you have a forward bow, it's from heavy strings. The guitar probably needs a neck reset, which is complicated, especially since a lot of Harmony guitars were built with no gap in the neck mortise/tenon to steam it out. It requires exposing the joint.

You made a good decision to replace the tuners. I've replaced most old tuners. Even if you have a working tuner from the era, they're hard to adjust because of the old gearing ratios; the pull of the strings makes them terrible to adjust. Plus the gears develop flat spots. I keep all of the old tuners that I remove, with the guitar, and return them to my clients after replacing them.

I look forward to seeing how you're doing.

[MaineGeezer]

StewMac sells all manner of screws for tuners and such, but you must already know that.

Figure out what the thread is, if you can. It may be non-standard, which will complicate things considerably.
Look up https://www.amazon.com/Screw-Chekr-Thre ... 7754&psc=1 and its metric equivalent.

McMaster-Carr (mcmaster.com) sells everything industrial, including a wide assortment of screws. They may have something suitable.

[MaineGeezer]

Consider getting a bottle of fish glue, either from StewMac or Blues Creek Guitars. I would NOT use Elmer's glue.

'

[rcnewcomb]

the neck has a slight concave bow

I rescued the 6-string version of this from a dumpster behind a music store.

I did a lazy neck-reset. I pulled off the fingerboard and placed shims under the fingerboard closer to the body. The steel reinforced neck was a piece of 1/8" thick steel that was 1/4" wide laying flat underneath the fingerboard -- not exactly rigid.

I replaced the bridge with one out of a scrap bin in Jim Olson's shop. I doubt there is another Harmony on the planet with a bridge carved by Jim Olson.

When I put it back together it sounded remarkably good, and it is my preferred camp fire guitar.

Best of luck on your project!

[Underwood]

Since my last post I stripped the finish using a 3M soybean-based remover. After testing a spot with acetone, I knew that the 3M product would work well. Apparently, it worked so well that my wife convinced me to strip the complete guitar. After soaking in for a few hours, I could scrape with a razor held perpendicular to the surface to produce what appeared to be gummy worms.

After stripping the top, I wet sanded using 320 grit wet/dry paper, used an eraser as a block, and Minwax hardwood floor cleaner as a lubricant. I sanded out the wear area under the 20th fret and most slight dings/scratches. I applied 2 coats of Zinser Seal Coat dewaxed shellac thinned 50% using a good quality synthetic bristle brush.

After stripping the bottom/sides/neck I again wet sanded using 320 grit wet/dry paper, used an eraser as a block, and Minwax hardwood floor cleaner as a lubricant. I again sanded out most slight dings/scratches. I sparingly used the lubricant and soon after I began, I noticed what appeared to be pore filler accumulating in addition to the finish/stain remnants. As soon as I noticed this, I did not flush the area but rather would wipe the paste back into the grain. I have Timbermate mahogany and will likely re-apply if I need to.

There are some dings in the bell/bottom corner of the body which I am hesitant to sand out. I'm not sure if the wet sanding raised some of the dings or that most scratches were not as deep as I thought. As I have some dings in the neck, I am considering steaming them out with a soldering iron. For the body, I will not attempt to steam any ding close to the binding. My goal is to remove enough of the original finish/stain such that when I apply a clear coat the guitar appears to be one color (no dark spots).

My wife prefers the natural color of the mahogany, and as I am restoring it to make her feel good about having her dad's guitar back in working condition, I will complete the finish by applying 2 coats of shellac, sanding back the shellac with 600 grit wet sandpaper, and apply a few coats of brush on Watco clear gloss lacquer thinned at 50-60% with lacquer thinner Using a quality natural brush).

I measured the neck bow using a straight edge and feeler gauges. The apex of the bow occurs at the 10th fret and is 0.023 in. As the suitability of the guitar is for a neophyte and for feeling good about, can I make the guitar more playable by increasing the saddle height a multiple of the 0.023? Perhaps increase the saddle height 0.046, 0.069? If anyone has any thought on the magnitude of a bow as described or approach like raising the action, I would greatly appreciate it. I am not ready to do any neck work other than finish work at this time. I think my wife's family would be very happy to have it look good and make an appearance once a year for jungle bells or silent night or maybe even happy birthday.

I received the ebony blank and bone blank saddle. After handling the materials, I think I need to do my homework on what tools I should use. I will likely use power tools to get a rough shape but am thinking that I will be using hand tools for the finish or even semi finish shaping. I think I need a day or two to get my finish hand planes sharp enough to sit on my workbench next to the ebony let alone put the blade to wood. If someone knows a link on working with ebony or to shape a bridge, please feel free to share.

Next Steps:

• Try spot steaming dark spots to lift dings

• wet sand dark spots

• apply 2 coats of shellac to body/neck

• fit the tuner collars

• reconstruct the bridge

• research working with ebony/shaping a bridge/fitting a bone saddle

Photos:

• 1st Row- 3M on top, top after 2 coats shellac thinned 50% with alcohol, lacquer gummy worms, 3M on bottom

• 2nd Row- un-sanded top, wet sanded bottom

• 3rd Row- wet sanded sided, shellac with deep ding, wear area with shellac

• 4th Row- bottom corner showing multiple dings/dark spots, top showing shellac buildup on sound-hole trim, sanded out prominent scratch with shellac applied

Screenshot 2021-12-06 190510.jpg

[Diane Kauffmds]

Since my last post I stripped the finish using a 3M soybean-based remover. After testing a spot with acetone, I knew that the 3M product would work well. Apparently, it worked so well that my wife convinced me to strip the complete guitar. After soaking in for a few hours, I could scrape with a razor held perpendicular to the surface to produce what appeared to be gummy worms.

After stripping the top, I wet sanded using 320 grit wet/dry paper, used an eraser as a block, and Minwax hardwood floor cleaner as a lubricant. I sanded out the wear area under the 20th fret and most slight dings/scratches. I applied 2 coats of Zinser Seal Coat dewaxed shellac thinned 50% using a good quality synthetic bristle brush.

After stripping the bottom/sides/neck I again wet sanded using 320 grit wet/dry paper, used an eraser as a block, and Minwax hardwood floor cleaner as a lubricant. I again sanded out most slight dings/scratches. I sparingly used the lubricant and soon after I began, I noticed what appeared to be pore filler accumulating in addition to the finish/stain remnants. As soon as I noticed this, I did not flush the area but rather would wipe the paste back into the grain. I have Timbermate mahogany and will likely re-apply if I need to.

There are some dings in the bell/bottom corner of the body which I am hesitant to sand out. I'm not sure if the wet sanding raised some of the dings or that most scratches were not as deep as I thought. As I have some dings in the neck, I am considering steaming them out with a soldering iron. For the body, I will not attempt to steam any ding close to the binding. My goal is to remove enough of the original finish/stain such that when I apply a clear coat the guitar appears to be one color (no dark spots).

My wife prefers the natural color of the mahogany, and as I am restoring it to make her feel good about having her dad's guitar back in working condition, I will complete the finish by applying 2 coats of shellac, sanding back the shellac with 600 grit wet sandpaper, and apply a few coats of brush on Watco clear gloss lacquer thinned at 50-60% with lacquer thinner Using a quality natural brush).

I measured the neck bow using a straight edge and feeler gauges. The apex of the bow occurs at the 10th fret and is 0.023 in. As the suitability of the guitar is for a neophyte and for feeling good about, can I make the guitar more playable by increasing the saddle height a multiple of the 0.023? Perhaps increase the saddle height 0.046, 0.069? If anyone has any thought on the magnitude of a bow as described or approach like raising the action, I would greatly appreciate it. I am not ready to do any neck work other than finish work at this time. I think my wife's family would be very happy to have it look good and make an appearance once a year for jungle bells or silent night or maybe even happy birthday.

I received the ebony blank and bone blank saddle. After handling the materials, I think I need to do my homework on what tools I should use. I will likely use power tools to get a rough shape but am thinking that I will be using hand tools for the finish or even semi finish shaping. I think I need a day or two to get my finish hand planes sharp enough to sit on my workbench next to the ebony let alone put the blade to wood. If someone knows a link on working with ebony or to shape a bridge, please feel free to share.

You need to run a good straight edge down the center of the fretboard. Typically, you want the straight edge to clear the bridge with about 1/16" to spare under it, above the saddle slot.

For string height, 3/32" above fret 12 is a comfortable height for all style of playing. When I do setups, this is where I start. I like to see ~0.017" at fret 1 and 3/32" at fret 12, on string 6, bass E. String 1, treble E will be slightly less. On a very good, straight board, I can go lower, but the above measurements are comfortable for beginners, but high enough for harder players.

Your saddle height will be dependent on these measurements, and how the strings lay up the board with the slight bend. You could simulate the above measurements, by clamping a string just above the nut, on the headstock, and run it down the fretboard, over the saddle slot location. If you have the new bridge, sit it where it needs to go. If not, place a block of wood of the same thickness where the bridge sits. Put shims over the saddle slot location until you have 3/32" clearance under the string at fret 12. Measure the height of the shims. This height is an approximation of your saddle height.

The height of the shims + the depth of the saddle slot will be a pretty good starting point for making your saddle. If the fretboard has a radius, your saddle should have the same radius.

If you don't want to go through all of that, you can just use your straight edge and when it's 3/32" above fret 12, measure the clearance under it where the saddle sits.

I use a bench top spindle sander to shape my bridges, which I always make out of ebony. I use a laminate router in a jig to rout the saddle slot. I hand sand my bridges to 1500g.

20201207_101703.jpg

[Underwood]

Now that the holidays are over, I have resumed the restoration.

I used a soldering iron and wet paper towel to remove dings on the sides and bottom of the guitar. I was surprised how well it worked. I sanded with 320 grit wet sandpaper and applied 3 coats of 50/50 dewaxed Seal Coat shellac/alcohol. My wife likes the finish so well that for final finishing I decided to sand back the shellac and apply several coats of thinned satin lacquer.

I installed Grover long shaft ukulele tuning machines which required slight enlargement of the shaft holes. I did not install the shaft collars as I would have had to re-drill the shaft holes to 0.357 inches (from 0.236 inches). The collars would have covered the harmony logo and I didn't want to increase the shaft holes (even if it is just one side for 1/2 the head thickness). If omitting the tuning machine collars is a critical error, please feel free to correct me.

I glued up the bridge to get dimensions for a new one and to test the action height. To my surprise, after installing the reconstructed bridge, the string height at the 12th fret was 3/32 inch. I decided to reproduce the bridge to the original dimensions. I set up my table-top router table with a Freud 3/32 bit. I ran a test/scrap block thru to verify setup and check the saddle blank fit. That is when I realized the Stew Mac Martin saddle blank was more than 3/32 inch thick.

The saddle blank measures 0.120 inches, which is 0.026 inches greater than 3/32 inches (0.094).

I have 3 options to move forward:

• Call Stew Mac and see if I received an off-spec saddle blank.

• Make 2 passes/adjust the router table fence offset to cut a 0.120 groove.

• Hone the saddle blank to 0.94 inches using a stone or wet sandpaper on a granite tile.

If anyone has experience with saddle blanks and can suggest the best way to proceed, I could use the help.

I tried option 2 on a test/scrap block and was successful despite the limited ability to make fine adjustments on my router table. I do not want to try that on the one piece of ebony that I have. I am leaning towards option 3 but would prefer to have a 3/32 blank from Stew Mac.

Photos:

• Reconstructing the bridge.

• Looking good with 3 coats of 50/50 shellac/alcohol for protection until I am ready to refinish.

• Using a jig to cut the ebony blank. Circumferential cut to avoid splintering.

• Grover long shaft ukulele tuning machines.

• 0.120 saddle blank thickness, Ugh!

Jan_8_2022.JPG

[Skarsaune]

That saddle blank is totally normal, in my experience.

Sanding saddles to fit is a common task. Keeping the sides parallel is the trickiest part.

[Diane Kauffmds]

Saddle blanks are thicker than needed so that they can be custom fitted.