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  #16  
Old 09-27-2020, 10:22 AM
Mandobart Mandobart is offline
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Thanks again for the updates!
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  #17  
Old 10-03-2020, 06:15 AM
Arumako Arumako is offline
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Default Binding Channels and Neck Prep

Thanks for commenting Mandobart. Starting to think this thread should be on the "Build and Repair" board... oh well, started here, guess I'll push forward to the finish unless an Administrator decides to move this thread... now that the box is closed, needed to cut the binding channels.



The Dremel Binding Channel Routing tool makes easy work of cutting the channels. Need to be careful to go slow and change directions to prevent tear-out. Super glued the bindings in and scraped the bindings down, filled cracks and tail piece screw holes. Now, onto the neck. The adhesives holding the fret board was extremely hard and no amount of heat on my spatula or the fret board would make it budge. Decided to cut-off the laminations first to see if a clean job could be salvaged.



Was able to get a fairly clean removal of the fret board, but it's gonna take a lot of slow work to get the glue residue clean and flat. Should not have been, but was really surprised by the neck joint. The cut to make space for the dove joint on the top is quite messy. The neck joint doesn't fit well and is filled with the same old hardened glue that was used to secure the fret board onto the neck. For better or worse, this neck is never coming out of the neck block.



After 5 painstaking hours, the neck is clean and flat. I read somewhere that these guitars had mahogany necks, but to my pleasant surprise, the neck is made from Japanese birch which is very similar to maple - very strong, and after 60 years, this neck will stay dead straight...



Ending a really productive weekend by filling the many tuning peg holes on the back of the headstock. I really like using medium viscosity super glue for this type of work. The super glue naturally seeps slowly into the wood. Just keep filling the hole until the glue mounds up and let it dry. Wait 24 hours and take a sharp chisel to flatten out the mounds...



Got the rosewood fret board on order as well as matching vintage tuning pegs. A lot of touch up paint and some lacquer re-coat to finish up. A bit more to go! Thanks for letting me share AGF!
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  #18  
Old 10-03-2020, 02:01 PM
rockabilly69 rockabilly69 is online now
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Great to see you're back at it and looking at the home stretch As always, great work you're doing! I can't wait to see how this turns out!
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  #19  
Old 10-06-2020, 02:52 PM
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ArchtopLover ArchtopLover is offline
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Quote:
Originally Posted by Arumako View Post
The bridge must be moved in exact parallel motion with the top to ensure the bottom of the bridge and the top meet flushly. Although it's simple, the process is quite time consuming. If the fit is not flush, full resonance will not be achieved.
Really love reading this post. You got some serious skills .

Just a suggestion, have you considered using a jig/fixture to help when you profile your archtop bridge feet? I discovered this tool by Stew-Mac that is perfect for making sure that the foot is perfectly contoured, or as you say, "flushy" (and at a right angle) to match the sound board top.

http://https://www.stewmac.com/luthier-tools-and-supplies/tools-by-job/tools-for-bridges/archtop-bridge-fitting-jig.html

I crafted a home-made version out of 1/4" plexiglass and a left-over band-saw blade roller bearing, that works just as advertised, and it does make a huge difference in overall tone and volume to make sure the bridge foot contact, or foot print is perfect and "flushy" .

Last edited by Kerbie; 10-06-2020 at 03:30 PM. Reason: Fixed quote
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  #20  
Old 10-07-2020, 09:03 AM
Arumako Arumako is offline
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Thanks for the comment and tip ArchtopLover. Actually, I was really having a hard time getting the bridge to sit perfectly on the arched top. No matter how much I sanded, the ends would be curled up ever so slightly, so I put the bridge aside for now. There's still plenty of material to work on the bottom side of the bridge; so like you, I'll definitely make my own copy of the jig when the time comes. Thanks again!
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  #21  
Old 10-18-2020, 12:06 AM
Arumako Arumako is offline
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Default Prepping the fret board

Had a chance to spend a bit more time prepping the fret board this weekend. Hope you all don't mind my sharing my progress. Sourced this beautiful 3A rosewood fingerboard from my supplier, and the first order of business was to flatten one of the sides. Really just a lot of sanding for this portion of the project.

My work bench is actually a round dining room table and while it's not a REAL carpenter's workbench it's folding sides really helps in my super cramped hackshop/office. It's also super flat and works perfectly for this kind of application. Been using this table for 15 years, but still need to measure for flatness just in-case there's any warping.

Double-stick tape some 220 grit metal sandpaper (more expensive than wood sandpaper but quicker work), and sand the bottom flat. After spending about an hour flattening the bottom, the fret board is rough cut and directly taped on to the flat table. Then it's radiused with 60 grit (wood) sandpaper using my 12" radiusing block.



You can see the pitting in the fret board from the planing done at my suppliers shop. Some areas are pretty deep so this is going to be a long sanding process!

After some sanding the edges begin to take shape and the coloration clearly identify areas that need work. Each sanding stroke needs to cover the entire fret board. It's tempting to concentrate on the areas with more pitting, but that will throw the lengthwise flatness of the fret board off. Long, consistent, precise strokes combined with frequent lengthwise flatness verification is crucial.



Cleaning the sandpaper frequently is also quite important. At first the paper only loads on the fringes; but once the paper starts loading all the way across as shown in the photo, I know I'm making consistent progress. Too much loading on the sandpaper may cause the wood to get gouged. As the sanding continues the beauty of the wood really begins to stand out. The nut end of the fret board is radiused just-right; but the sanding still needs to cover the entire length of the fret board.



Just a little bit more to go... Man, this rosewood is just beautiful! The elimination of the discoloration indicates that the radiusing is complete. It's still a rough job up to this point, but it's important to verify the lengthwise flatness. Also, the radiusing sanding block is moved over the fretboard to ensure there's no light that seeps through at any point.



After 2 hours or so, the rough radiusing is complete and the fret board is flat and straight. It sits on top of the neck with no gaps and the neck angle is perfect! YES!



By rough radiusing the fret board, my fret slots can be cut with the same radius as the fret board. When the frets are installed, there's no gap between the bottom of the fret tang and the fretboard under the middle section of each fret. It all fits nicely with no need to use super glue as a filler. The old masters didn't even need to use glue to keep the frets in place!



The fret board really is perfectly suited for a Japanese guitar of this vintage. I can't be more pleased! However, before installation, the fret slots need to be cut and the binding installed. To do this, I'll need to make a custom jig based on the shape of the flat side of the neck. Then finalize the fret board shape and fret slot depth, add binding, then finalize the fret board radius with 1000 grit sandpaper... then, I can glue the fret board onto the neck and continue from there...whew another productive weekend!

Just received the vintage tuning pegs (really hard to find!) that fit perfectly too! Woohoo! Thanks for letting me share AGF!
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  #22  
Old 11-01-2020, 03:40 AM
Arumako Arumako is offline
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Default Fretting over Fretboards and Other Minor Points

Hello AGF. Hope everybody is hanging in there. Things in my neck of the woods are relatively stable; and guitar project progress is slow but significant.

So, just as I settled on my rosewood fretboard, wouldn't you know that my supplier put some ebony up for sale at 50% off! One piece was pitted pretty badly, but had a beautiful lighter hue streaking through the fretboard length...of course, he offered a further discount and I just couldn't resist!



Wasn't sure if the board would have enough thickness after radiusing, but it does (barely), and I'm really liking this. Ebony is much much harder to radius, but... I dunno... rosewood or ebony?



Can't make up my mind, yet; so, needed to improve the area under the fretboard extension. The right shim (treble side) came off easily with a bit of heat. However, an unexpected crack in the sound board under the left shim made clean removal impossible. First, the cracked top and left shim needed to be glued back together using Titebond and clamped. Then the shim was removed with a sharp chisel instead of heat. The structural integrity of the area was verified and finished with some 600 grit sand paper.



Of course, the area under the fretboard extension needs to be rebuilt; so some scrap from the ebony fretboard was used together with some old reclaimed Canadian birch hockey sticks. Years ago, a hockey enthusiast friend had some old sticks that were broken or unused, and gave the scraps to me. I really enjoy working with this wood and they are used sparingly in my projects whenever appropriate.



Before the fretboard extension is finalized, the gap in the dovetail joint needed to be addressed. There's just enough room for a small file to clean inside. A piece of scrap Koa will be shaped and glued into the gap.



On to the bridge...really wanted a bridge with a bone saddle, but couldn't find one with an ebony base. The bridge is a bit too light in color; so, some flat black nitro-cellulose lacquer was thinned to about 7 parts thinner and 3 parts paint. Rubbed clear thinner into the bridge, then proceeded to rub the bridge with the thinned out flat black lacquer. The lacquer seeps a bit into the rosewood and acts a bit like a stain. You can still tell it's rosewood, but the color is darker like...walnut. It will go well with either the rosewood or ebony fretboard.



With a pressed arched top that's at least 50 years old, it's quite difficult to have a completely symmetric arch. The few cracks in the top also make it really difficult to match the top arch to the arch in the bottom of the bridge. I'll definitely need to use the tool that ArchtopLover talked about earlier in this thread; but for now, I needed to resort to the "sandpaper pull" trick to get the bridge flush to the top. It's still not perfect, but it's much much closer.

Only small steps of progress this weekend, but really pleased with where things are headed! Thanks for letting me share AGF! Stay safe everybody!
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  #23  
Old 11-01-2020, 06:18 AM
Mandobart Mandobart is offline
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Wow! I've never put this much work into an instrument. I've just done some pickup installations, bridge and nut replacements, swapped out tuners etc.

Truly a labor of love that shows patience and skill! Thanks for sharing this project.
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  #24  
Old 11-03-2020, 08:20 AM
Arumako Arumako is offline
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Default Fretboard Extension Support

Thanks for the kind comment Mandobart. This restoration is thoroughly engaging for me. Hope it will be of some help to anybody else attempting restorations somewhere out there. Despite being inexpensive, a 50 year old solid spruce top, pressed or not, is hard to toss into the garbage!

The Koa neck block filler took awhile to shape. A lot of scraping and sanding, but in the end the shape came out pretty good. The extra length ensures the piece doesn't get stuck in the slot prematurely. It's not perfect, but it will do well enough. Some years ago, my mentor gave me a bunch of tools, and this Japanese hand planer is one of them. Called Titebond hide glue into service again and was really surprised with how much the neck block (not the Koa) soaked up the adhesive.



Despite cool weather, the dry autumn in Japan allowed the glue to dry quickly. Taped up the body and sawed off the extra Koa. A sharp chisel and some Koa powder from previous builds with CA glue (to further fill any gaps) completed this part of the restoration.



Now, it's time to turn my attention to the fretboard extension support. The Ebony/Canadian birch glue-up is looking really good. Turned to my Dremel Motosaw (scroll saw) to rough cut the neck cavity into the extension piece. The Motosaw is nice for general work, but it's not a good tool for final cuts and finishing cuts. Lots of chiseling, scraping, filing and sanding to get the piece into its final specs.



The long Ebony scraps from my fretboard used in this glue up will be cut-off later. Leaving them in place gives me something to hold onto when shaping the piece, and they serve as nice alignment tools as well.



Got the neck cavity in the fretboard extension support to fit nicely. Now, contouring the bottom of the fretboard extension support by hand is gonna be really hard. That'll be an all day project; so, gonna call it a day for now. Getting closer and closer!

Thanks for letting me share AGF! Praying that everyone will be safe and that the elections will proceed peacefully!
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  #25  
Old 11-14-2020, 05:36 AM
Arumako Arumako is offline
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Default Contouring the Fretboard Extension Support

Shaping the new fretboard extension support was as time consuming as expected.

It's really important to get the arch contour above the neck block correct. It's the area of the soundboard that has the most contact with extension support area and provides a solid footing. Rolling the pen along the inside diameter of the washer gives me a perfect mirror image of the contour. The tape is then fitted on to the extension support to ensure the piece is contoured accurately.



Once the basic curve is carved into the sole of the extension support, the pattern is drawn into the sole with a pencil. In this particular case, minimizing the contact patch of the extension support and the soundboard is the goal. This extension is going to be contoured to allow for soundboard contact above the length of the neck block and two points at the forward tip of the extension support.



Thanks to the Canadian Birch, the extension support can be really thin, and when combined with the Ebony fretboard, there will be plenty of stability even if the higher frets are played (a minimal issue for a non-cutaway archtop).



After hours of routing, carving, filing, scraping and sanding, the extension support needs to be leveled and fitted.



Just a little bit more to go for a final fit! Really excited to get to this point. Hope to be finalizing the fretboard with binding and fretting in the next two or three weeks and then on to final assembly and finish touch-up...

COVID-19 seems to be surging all over the world; so stay safe everybody! Thanks for letting me share!
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  #26  
Old 11-20-2020, 09:12 PM
Saxonbowman Saxonbowman is offline
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Great thread! I love seeing how this goes together. Once itís done youíll forget how much work it was and how long it took. It will just be a wonderful guitar brought back to life.
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  #27  
Old 11-23-2020, 01:28 PM
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Default Watching and Learning

Arumako, it's wonderful to watch this archtop restoration in progress. Your fretboard extension is just gorgeous. The attention to detail and the artful sculpture of the profile is quite lovely; too bad it will be hidden under the fretboard, where no one will see it, in all its glory.

I am curious, though, what was your reasoning for filling the small gap, or pocket, between the neck heel and the neck block? In your thread, you mention that "The cut to make space for the dove joint on the top is quite messy". Was it simply because the joinery appeared rough and unfinished, or was there another purpose, since the strength of the joint is mainly achieved by the fit of the dovetails?
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