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  #16  
Old 03-24-2020, 07:10 PM
murrmac123 murrmac123 is offline
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Originally Posted by charles Tauber View Post
Third, it assumes that simply rubbing something flat across something that isn't will make that something flat. It generally doesn't: it will generally make it convex. So even if there is consistent abrasive-time, it won't guarantee flatness.
The manufacturers of lapping machines are going to be really upset to discover that their products don't actually produce the desired result.
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  #17  
Old 03-26-2020, 02:19 AM
nikpearson nikpearson is offline
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Originally Posted by charles Tauber View Post
As MC5C stated, "I never particularly worry about getting fretboards flat, I think more in terms of equalizing fret heights between adjacent groups of frets." That is the approach that I use as well.

Occasionally, the question comes up of how to prepare the joint in the centre of a guitar top or back. During that discussion, often, someone asks whether or not it is easier to obtain a perfect joint using a longer (jointer) plane. The usual answer is no, not really. Simply running a longer plane - one which keeps more of the sole of the plane in contact with the plane of the wood joint being prepared - back and forth over the joint won't produce a perfect, straight joint any better or faster than a shorter (smoothing) plane. Again, it is largely technique and observation/feedback.
That’s interesting Charles.

I’ve found that jointing tops and backs is quite hit and miss with a plane - I usually use a bevel-up jack plane - if I’m lucky it takes me half an hour, if not much longer. I often end up chasing humps and dips up and down the board length. A very sharp blade and very fine cut help, but still it’s tricky to get absolutely no gap along the full length when viewed on a light table.

When I discovered I could use a 24” levelling beam after initial planing this task became a doddle, literally a minute or two of work. The results are a joint I struggle to find when remarking centrelines and one where not a photon (slight exaggeration I know) of light can be seen when placed on light table

Maybe it’s down to my poor technique but I see other students having the same problem, or settling for just good enough. Always interested to hear thoughts from more experienced builders.
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  #18  
Old 03-26-2020, 07:24 AM
redir redir is offline
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There is definitely an art to joining tops and backs. I can tell you what works for me and that is to focus on the middle till I have a nice 'Spring Joint' which essentially is the middle dug out so you can see light dead center at it's widest spot tapering off to zero at both ends, kind of like a cat eye. Then I take the plane on the shooting board and take full strokes till there is no more light. Usually I will go a bit too far and have to start over but I can join a top in 15 minutes now.

So instead of chasing humps per se build your own error into it then take it out.
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  #19  
Old 03-27-2020, 02:30 PM
Simon Fay Simon Fay is offline
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Originally Posted by murrmac123 View Post
The manufacturers of lapping machines are going to be really upset to discover that their products don't actually produce the desired result.
I think Charles is talking about hand work here (correct me if I'm wrong, Charles). As mentioned, it is easy to get a convex surface when sanding with a flat beam instead of a perfectly flat surface. However, good technique can EASILY overcome this tendency - so it really isn't a big problem but one must be mindful about what they are doing. Generally, a novice woodworker will definitely end up with a convex surface, so it is certainly worth mentioning in this thread.
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  #20  
Old 03-27-2020, 06:23 PM
mirwa mirwa is offline
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Originally Posted by Simon Fay View Post
Generally, a novice woodworker will definitely end up with a convex surface, so it is certainly worth mentioning in this thread.
Spot on, I run a few acoustic guitar building courses each year and this is the hardest thing for newbies to get right, even with the right tools and correct instruction, most struggle to get a relatively flat edge or surface, its an acquired skill

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  #21  
Old 03-27-2020, 08:01 PM
Gottaplay Gottaplay is offline
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Speaking about acquired skills Holy Cow was that a lot of work. So the workbench was a guitar bench today and it was a bit of a marathon for this relative newb to DIY guitar luthery.

It turns out I misnamed this thread. It should have been more along the lines of "Make your own tools and self correct over and over again" or "Fret leveling 'til the cows come home"or "Buy yourself a perfect fret rocker gauge cuz close don't cut it".

So going back to the beginning I was figuring on using a 24" spirit level to flatten out my buzzing fret board. Well my guitar wasn't too bad for next fret comparison leveling up until the hump at the 14th. From the 12th fret to the nut there weren't any massive wows but up high it was ski jump city and the refret guy was on lock down so Mr. Cheapskate here made a 8" sanding block with 220 and 340 grit and had at it. I make it sound rough and fast but actually took way too long and I rechecked my work way too many times but that's kinda the way I tend to approach first timing a new difficult challenge. Feels good when you get it right and yeah my chest is kinda puffed up at the moment. Tomorrow I`ll dial in the saddle but it's really close.

With so much good feedback received on this thread I followed up on some of the quoted sources and it really paid off. More later but it's getting late just wanted to say thanks and be well. Hope you and yours are OK.
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  #22  
Old 03-28-2020, 08:53 AM
phavriluk phavriluk is offline
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I infer from OP's latest comments that the idea is to get the fretboard flat, not the tools. Sounds good to me.
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  #23  
Old 03-29-2020, 06:27 AM
Gottaplay Gottaplay is offline
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This whole thing kicked off when I finally got tired of a buzz somewhere up the neck when capo'd at the fifth fret and half assed flatpicking the intro to Tennessee Stud, The fifth and six string buzz when digging in a bit really bugged me. The reason I left it for several months was that I had already spent days working on the guitar in the early fall which was terra incognita for yours truly. The removal and regluing of the bridge went very well but making al the tools for it and discerning the good info from the not so good info then the actual work itself was pretty time consuming. Would I do it again...oh yeah but you just can't fix stupid so I may never learn in that regard.

For the frets I used new olfa blades as rocker gauges, not really accurate, 1/8 aluminum L bar for notched straight edge and leveling beam,again close but no cigar. Close but not really proper. It played better when done but I was fearful to take on the neck block hump that came with the guitar so getting the action as low as was practicable for some upcoming shows was as far as things got.

One silver lining of our current situation and a welcome distraction was revisiting the playability issue and addressing the entire fret board. I knew enough to not attempt even a partial refret myself and the hump was not so drastic to rule out some serious material removal and well I almost never play above the 14th fret anyway. So a very flat leveling beam seemed to be a good bit of kit to begin with. turns out I was wrong, Ooops. Instead Iused some 1 3/8 bamboo countertop scrap with 220 and 340 grit using the CCA glue and painters tape trick..worked great.

Taking my time to carefully check the highs and lows revealed that localized and careful filing could theorectically flatten the frets below the 12 th fret thus saving fret material and longevity and that worked out great albeit requiring upteen cycles of checking and easy filling. Not really practical for professional repair or production work I`d guess.

With the frets all even (yes there's fall away from the 14th upwards) and blindingly shiny it was time to dial in the action and relief and to try out a bone saddle. All the talk about bone vs Tusq had me wanting to give it a try. Lost count of the number of times I stung it up then took 'em off never mind how mant strings snapped...long story shortened I got the action down to E 6/64 and e 5.5/64 and relief E 4.5/64 and e 4/64. No buzz when finger picked, strummed or flat picked in a controlled manner but a hint of buzz digging in capo'd at the fifth but I'll take that tradeoff for the way it plays. By far the best playing and sounding guitar I`ve ever had. Sure I`d love a Boucher Studio Goose but champagne taste on a beer budget reality was how I found the L-03 in the first place It feels...I dunno...unified and in synch??? I know it's not a valuable guitar and it doesn't compare to the droves of high end guitars out there but it's a player and will hold it's own respectfully.

Never would I have considered talking on these daunting tasks without the considerable knowledge and sharing that is provided by the members of the Acoustic Guitar Forum and other guitar forums and independent luthiers out there. Thanks so much. Be well.

Last edited by Gottaplay; 03-29-2020 at 06:58 AM.
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