Practice build woods

[Sadie-f]

Originally Posted by phavriluk

A thickness sander makes short and accurate work of sanding to desired thickness all the tonewood, top, back, and sides. Scraping and planing is unnecessary work with ambiguous results compared to what comes out of a thickness sander. From the sound of OP's description of the wood shop that can be used, there's one in there somewhere.

Yep, I'm aware of what can be accomplished with a thickness sander, and how much more time will go into thicknessing by hand (it won't come up to the time I've put into hand finishing either of 2 electrics -- tung oil). The difficulties of consistency are obvious. However, no, the shops I have access to do not have one.

[Fathand]

Originally Posted by Sadie-f

That's pretty much the plan. Yes, I've got access to a large and well maintained band saw, an oscillating drum sander that will come in handy, multiple choices of belt sanders. I'll probably use a cnc router for the sound hole & rosette work. I plan to plane and scrape for thicknessing. I'll have to build my own bending setup, and likely a gluing frame.

OM / OOO size is the plan.

You can make practice tops from (usually) spruce 2x8s or similar. Find a clear section about 18-20" long that comes close to quarter or rift sawn. Resaw it to 5/32" or so and glue up some "dummy"tops. You can practice things like thicknessing, rosette channels, rubbing in a sunburst or finishing with them. Alternately I have bought factory or 2nd grade tops as low as $4.

CNC router is overkill for rosette channels and soundhole, I use a dremel on a circle cutter, a router might work even better. No programming required. I bought a set of 15 bits, 1.5mmto 3mm on Amazon for $17 Cdn. I usually use a bit .1 or .2 mm larger than the purfling strip I am inlaying.

I have documented some builds here with my "poor man's " methods, including my bending process and mold making. Maybe you can get some ideas you can use.

https://www.flickr.com/photos/194462017@N08/albums

Good Luck

[Sadie-f]

Originally Posted by Fathand

You can make practice tops from (usually) spruce 2x8s or similar. Find a clear section about 18-20" long that comes close to quarter or rift sawn. Resaw it to 5/32" or so and glue up some "dummy"tops. You can practice things like thicknessing, rosette channels, rubbing in a sunburst or finishing with them. Alternately I have bought factory or 2nd grade tops as low as $4.

CNC router is overkill for rosette channels and soundhole, I use a dremel on a circle cutter, a router might work even better. No programming required. I bought a set of 15 bits, 1.5mmto 3mm on Amazon for $17 Cdn. I usually use a bit .1 or .2 mm larger than the purfling strip I am inlaying.

I have documented some builds here with my "poor man's " methods, including my bending process and mold making. Maybe you can get some ideas you can use.

https://www.flickr.com/photos/194462017@N08/albums

Good Luck

That's a great bunch of notes, thanks!

I agree the cnc is overkill! However it's sitting there ready to go, it's used a lot of course, still finding a clear hour to use it is super easy :-).

[printer2]

I bought a lot of guitar friendly softwood from Home Depot. While it took a number of visits I found a number of quartered pieces. Some of the off quartered ones were meant for sides in spruce/pine guitars.



For practice, even the less than ideal wood can be used. I made a small guitar out of a fence board and it turned out fine, had it over a winter and no problems with cracking (no care taken with it).

[Aspiring]

Originally Posted by Fathand

You can make practice tops from (usually) spruce 2x8s or similar. Find a clear section about 18-20" long that comes close to quarter or rift sawn. Resaw it to 5/32" or so and glue up some "dummy"tops. You can practice things like thicknessing, rosette channels, rubbing in a sunburst or finishing with them. Alternately I have bought factory or 2nd grade tops as low as $4.



CNC router is overkill for rosette channels and soundhole, I use a dremel on a circle cutter, a router might work even better. No programming required. I bought a set of 15 bits, 1.5mmto 3mm on Amazon for $17 Cdn. I usually use a bit .1 or .2 mm larger than the purfling strip I am inlaying.



I have documented some builds here with my "poor man's " methods, including my bending process and mold making. Maybe you can get some ideas you can use.



https://www.flickr.com/photos/194462017@N08/albums



Good Luck

I picked this template out a number of years back when I needed to cut some large circles out of plywood for one of my kids projects.

I have used it for a large number of projects since. It makes a lovely guide for making a perfectly round cut with my plunge router and then whichever bit I would like to work with
.https://a.co/d/02L29yk

Sent from my motorola edge (2021) using Acoustic Guitar Forum mobile app

[RoyBoy]

I will echo what Bruce and Alan have said: Buy a lower grade of spruce for the top. The soundboard is huge in determining the sound of the guitar. Cheap pine is not likely to get you a decent sound, whereas a lower grade spruce could turn out excellent with proper thicknessing and bracing. I also agree that you should approach this with the attitude that you can get a decent sounding instrument out of your first effort. It may not be aesthetically perfect as you are perfecting the joinery skills, but you should minimally have a nice campfire guitar (for playing around the campfire, not burning in it) when finished.

Top thickness is critical, 0.010" can make a real difference. You can order soundboards thicknessed for for a small fee from Luthier's Merchantile. Down the road you'll want to get or make a deep throated caliper with a dial indicator.

For backs and sides, walnut and cherry are easy to come by and some high end luthiers build great guitars from those native woods. There just isn't as much market for them as players have come to expect mahogany or rosewood. I would dig around for vertical grain as much as possible.

I am curious about your ultimate goal of spruce > maple. Maple is not real common in the acoustic world. It works well for a strong punch in archtop instruments, but lacks the sustain, resonance, and sparkle of other tonewoods in flattop guitars. For recording and stage work it can be an advantage, but generally for acoustic playing, the other tonewoods are more often used.

Enjoy your luthier adventure!

[Sadie-f]

Originally Posted by RoyBoy

I will echo what Bruce and Alan have said: Buy a lower grade of spruce for the top. The soundboard is huge in determining the sound of the guitar. Cheap pine is not likely to get you a decent sound, whereas a lower grade spruce could turn out excellent with proper thicknessing and bracing. I also agree that you should approach this with the attitude that you can get a decent sounding instrument out of your first effort. It may not be aesthetically perfect as you are perfecting the joinery skills, but you should minimally have a nice campfire guitar (for playing around the campfire, not burning in it) when finished.

Top thickness is critical, 0.010" can make a real difference. You can order soundboards thicknessed for for a small fee from Luthier's Merchantile. Down the road you'll want to get or make a deep throated caliper with a dial indicator.

For backs and sides, walnut and cherry are easy to come by and some high end luthiers build great guitars from those native woods. There just isn't as much market for them as players have come to expect mahogany or rosewood. I would dig around for vertical grain as much as possible.

I am curious about your ultimate goal of spruce > maple. Maple is not real common in the acoustic world. It works well for a strong punch in archtop instruments, but lacks the sustain, resonance, and sparkle of other tonewoods in flattop guitars. For recording and stage work it can be an advantage, but generally for acoustic playing, the other tonewoods are more often used.

Enjoy your luthier adventure!

Thanks for the feedback Roy, yes I have access to good measuring tools, for now I'm set there, and could build a deep throat snap gauge easily enough.

The pine for now thing is because I've read about good instruments being made from it. I wonder if the best pine might not be an improvement on mediocre spruce?

I've learned in this thread the potential value of damping, and cedar is the other main contender for a first guitar. I like the sound of cedar a lot, and suspect I could qs a piece of 4x4 cedar to be glued into a good sounding top.

The reason for maple is I've heard some fantastic maple body instruments and played one that was nothing short of astounding. I've been working on a maple body soloist electric that I've just assembled and it really hits well in comparison to my rosewood > mahogany Strat.

So a proposed maple OM would be a sister to that soloist. About tops, when I first embarked on this plan, the guys at TME felt maple would be best topped with spruce, and I'm inclined to think cedar would pair better with a warmer b&s, say mahogany?

What I hope to achieve with maple would be more chime, less warmth, and if that comes with less sustain, that's acceptable. Why not rosewood? .. I've got an om-28 that's beginning to round out beautifully at nearly 3 years playing, and I'm waiting on an adi > rosewood SCGC OM.

Here's my picture of tonewoids at this point.

For tops, cedar offering compression and maybe best single note definition, spruce offering more power and resonance -- in the latter I've heard samples that were surprisingly damped, as well as some that rang with bell like tones. Again, eyes now open to damping can be a positive.

I compare to soda lime glass vs leaded glass, the former rings pretty dull, the latter makes great bells. Then there's fused silica which has no fluxes and is much harder to work with it's far stiffer and makes a very different tone from leaded glass, still an excellent choice for a bell.

Bell bronze is also extra special among metals, low damping and quite dense compared to steel, again they have extremely different tones, while brass makes a poor bell by comparison .. though also much less expensive.

B&s woods seem like this. I think rosewood & mahogany can both offer warmth with different resonance and damping. This is where I think maple differs, warmth isn't something I hear in it, so my picture is it offers less complex resonance.

When I started this plan, I still hadn't heard a mahogany guitar that really worked for me. That's changed now and where 9 months ago my plan was to simply build a maple < spruce guitar, I've now added one or more practice builds and the possibility of a mahogany build.

I'm still thinking the maple first, however I'm open to evolving the plan to mahogany instead. Still, as of now my leaning is to build my maple ideal, and maybe after that, a mahogany body.

But that's years down the line, lots more to learn along the way.

[Alan Carruth]

RoyBoy wrote:
"Cheap pine is not likely to get you a decent sound..."

Actually, my students, and other folks I know, have made some very nice sounding guitars with pine soundboards. The stuff we've gotten tends to be low in density and surface hardness; more like cedar than spruce, but if you use it right it works fine.

I'll note that, in terms of long-grain stiffness at a given thickness, all of the softwoods I've tested have tended to follow the same rule when you control for density. A pine top that has a specific gravity of .35 will usually have the same bending stiffness along the grain as a spruce one of the same density and thickness, or cedar, or redwood, or and other softwood. That's because all softwoods have a very similar microscopic structure. Cross grain stiffness is another matter, of course.

I'll note that damping is one thing that varies a fair amount between different softwood species. Redwood and Western red cedar both tend to have much lower damping than the spruces in general, and pine is usually higher. Damping in wood is a tricky subject. For one thing, it seems to vary with frequency, although it's hard to say why that might be in general: one researcher (Haines) speculated that the variations he saw may have been artifacts of his measurement method, but couldn't figure out how that would work.

We also have to draw the distinction between 'material' and 'structural' damping. I think that one of the reasons it's so common to see bad instruments made from good wood is that it's easy build in extra damping. Badly done glue joints, 'improper' bracing, and the 'wrong' finish can all kill the sound. I suspect that material damping sets a lower limit that is probably difficult to approach in practice. That's one reason a good luthier will make a better instrument from poor wood than a poor luthier would make from the best wood. If course, the good luthier will probably get better results from better wood, but I wonder if any of us ever really gets everything out of it that's there in theory.