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Some do deflection with the outline of the guitar already cut into shape. Deflection is all about consistence from guitar to guitar but when I do it, I do it to obtain YM and that has to be done with a perfect piece. Trevor Gores acoustic method does too. I'm not sure how valuable deflection would be on ablong pieces but again if it's consistent then over time it might be meaningful.

As a supplier though I can see where it makes really good sense to make it so that the client doesn't even have to think about which side of the top to join and old school luthiers rely on instinct at various stages of top thicknessing and bracing anyway. I personally feel like I am at the stage where I am using a bit of the scientific/engineering methods to help me confirm my instincts before I release myself to the wild

I'm on board with the importance of consistency in how deflection measurements are done. What I'm wondering is if the difference in deflection values between standard rectangular plates and similar size non-rectangular plates of the same stiffness is be big enough to matter in practice. I guess I'll do the experiment on my next top and see.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I would rather have the extra wood from a rectangular plate, and be able to decide for myself what edges I want to join, and determine the run out for myself.
Suppliers are free to offer the goods in whatever form suits them, and I am free to buy from whomever suits me, so no harm, no foul. That certainly is a nice looking top Mr. Hix pictured, but would be hard for me to take measurements from.

Ollie Rogers actually found a way to get the numbers from violin wedges, so it has to be possible to come up with a spreadsheet that would get you the Young's modulus of a tapered piece.

The violin folks will often test strips cut along one edge or across the end of the piece if its big enough. That assumes the properties are pretty much uniform throughout, which we know is not the case in many tops. There are pitfalls in making any measurement.

If you're only interested in how stiff the piece is, and don't need the Young's modulus, cutting the piece to shape and then measuring the deflectino in a standard way should be fine.

I will too. Should be about another month for me but I'll try to remember to report back.

Reporting Back

So I did two tops yesterday and the difference in deflection from the squared off board and the cut out top was pretty small. The difference was on the first one was .005. The second one had a difference of .025. Each top was about .25 in of deflection in accordance to my method.

So that's interesting. Cutting the guitar top to shape only made a slight difference in deflection.

It doesn’t help if you’re using the G/G method of capturing the freqs to get your thickness, but there is a workaround for nosed tops, I’ve used it a few times but not recently.

Basically get another top ready for the same model (or at least the same deflection if you have more than one model that takes the same deflection like a square D and a slope D), then thickness it to your desired deflection. Then cut the same shape into it as the nosed top and measure the deflection, then put that number into the nosed top. Maybe not perfect but close enough to play ball…

I'm thinking along the same lines.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I’ll be interested to see your deflection number differences when you nose the top. My intuition says there’ll be a significant difference as I’m guessing the only part of the top that matters deflection wise would be grain lines that go all the way lengthwise from beam to beam. So if a normal top was 18” wide, but a nosed top only had 12” continuous, that should reflect in the deflection number. But hey, that’s what testing is for. I gotta do a top in the next few days so I’ll do some measuring…

I accidentally stumbled onto this thread a couple weeks ago and "consulted with myself" whether to chime in or just let it go.
I gotta chime in.
And I'll fess up as to the culprit that sent such trash as referred to by some. I want Thank some of the experienced luthiers and wood people here.
Allen Carruth, John Arnold, John Hall for stating the obvious to the monday morning quarterbacks.
I want to start my diatribe off with some confession
I probably wrongly assume that everyone I'm sending product to is true experienced craftsmen.
I believe that building a guitar requires a lot of craftsmanship.
Secondly, I probably shouldn't but do, assume others are as conservation conscious as I am in regards to the old growth forest. The Tongass, Right here, Is the last intact old growth rainforest in the USA. And there is little remaining that is touchable in reagrds of any type of harvest for guitar tops.
Thirdly, I do my best to treat others as I wish to be treated, and will never send anyone anything that I would not use myself at the grade/price of the transaction. I value everyone of your's time as my own. We are each blessed with a given number of minutes of life, and no minute, no second is ever done twice. Our time on this earth is valuable.
Forthy, Given that I believe I'm dealing with skilled craftsmen and ladies, I believe taken the other aforementioned confessions, I will sometimes send top sets that I could not send to a manufacturer that we supply Like CF Martin and Gibson Acoustic, because the ability for the craftsman to work with close tolerances that the factory worker cannot and will not. Like Martin there needs to be 1/4" or more of space between the outside of a d-28 pattern and the defect. pitch pocket or whatever. Mainly because they are taking near a 1/4" off the edje to make a glue joint, when all that is necessary from what we produce is 1/16" or less.
Also a reverse side defect pitch inclusion or a split whisker. Things that will obviously sand out.
I candle boards that have these issues with a 1000 watt led light that's on a peddle switch in a picture I've setup in the grading room to know these things. I look for any evidences that the effect of the reverse side element does not come through, so that all normal thickness sanding can be dome on the reverse faces, and leaving just cleanup and finish sanding to the money face.
Again I reiterate, I won't send anyone anything I wouldn't use myself [ if I built guitars]


The customer did get a replacement. But before I spent my hard earned money to make him happy, I tried to educate him to what he had in his hands. The process the everything I could about the soundboard and grade.
I stand firm that the set does indeed fall into the Master Grade sort.
It meets this criteria
1. Perfect Color- nearly as white as norway spruce- no color variation in the pattern
2. Perfect texture- Fine straight grain with just slightly graduating growth lines aprox. 20 to 14 gpi
3. strong medularies across the whole board, meaning the board is cut perfect VG from a log that had a centered heart. as opposed to a log with an offset heart which would yield something different unless cut from a specific quadrant.
4. no apparent grain slope at the joining edge, which would cause what I refer to as black/white syndrome. Caused from light refraction from one half and reflecting from the other.

Like it or not people buy with their eyes. And 90%+ of grade criteria is attributed to the visual of the patterned area. Color and texture the main focus points. Whatever is outside of the patterned area if of no concern to the "Guitar top" soundboard.
It seems silly to grade a "sound board" by looks rather than sound. But that's the way it is.

It is obvious There is grain slope at the outer edge in this board. That slope is .9" per lineal foot on that edge, 1 " in at the edge of the lower bout it's already .1" less, gradually lessening .1" per inch all the way to 0 at the joining edge.
We are soundboar producers EXCLUSIVELY. Full time for 28 yrs.
I know my poop.
90+% of all log has some twist, the amount of allowable twist is determined by the diameter of the given log. And where that twist is in the board makes a lot of difference.
We seldom cut log that is under 36" diameter. We could, but we don't, except for cutting radially for achtop, mandolin and violin wedges.

We determine when blocking the log, which edge with be the joining edge of the cut guitar tops and dissect the round into said block accordingly.
This is one of the reasons we don't buy block from other.. They don't cut boards and they only know how to bust up a log. And in my business to me means they don't know poop, but how to cut firewood.

Boards from this log, produced by any number of other mill operators approach the processing in different.
Boards coming off a dimensional sawmill , mills that produce piano soundboards and other high value products from old growth timber
will have all the grain slope at the joining edge. Very bad!
Others that dissect from split block as we do; some go for highest recovery and will follow the orientation of fiber at the heart and again all the grain slope is at the joining edge. Again BAD!
Another producer will put that block up to the fence and split the difference so that there is a little runout at the join edge, none in the middle of the board and a little at the extremity of the lower bout. this still will result in flash at the glue joint.

Our approach is from knowing the highest stress is from the strings in the middle of the joined bookset.
and the least loading is at the extremities of the rim of the guitar where it is glued to sides to make the box.

Also some have stated that the board has to be visually pleasing. and apparently is looking at the oval pencil marks that the customer circled with great concern.
Those are the bottom of the saw marks that didn't sand out in the pass through the wide belt sander. the dept of thos marks is .003". the thickness of a human hair.. This on a board that is .190 and will get sanded to near .100. But even joining, different folks have different recipes and will join between.125 and whatever. Stew mac sanded boards are .125-.130 and their rough boards are .150?
We sand for just 2 reasons, some uniformity in stacking inventory, and to clean up enough to see and grade by the criteria we use to grade.
Here is a link to a Hi Def image of the set https://drive.google.com/drive/folders/ ... drive_link
Allen mentioned the color he saw in that section of the initial picture.
As you can see that is not what is going on here.
Allen referred to a drastic change in a tree's growth history.
A change caused by some big event in that tree' life. That could be by fire, a tree that survived a fire,[Fire is extremely rare in our temperate rainforest] and large blowdown event[ this we have MANY of. with winds exceeding 100mph.[ we've had 4 such events this fall], where many surrounding trees were either broken or uprooted and our tree remained, and with all the sunlight that promotes photosynthesis, that tree now has accelerated growth, from wherever it was with the heavy canopy of 16-20+ GPI, TO ALL OF THE SUDDEN, 6-8 or 10 gpi. There will generally be a sap line associated with that drastic change and a heavy twist. But as one can see. this little spot of pink sap bleed was a wound healed over. a wound from a branch of a neighboring tree slapping it in a windstorm as a or a limb from a dead tree that lost integrity to stand and collapsed.

Safety meeting in a couple hours, were we The ASW crew, have friends and family over every friday after work to eat something good and talk about everything under the sun. Current events, politics, food gathering, building stuff, hunting and fishing, you name it, play pool and have a GREAT time.
Pacific Geoduck fritters is the protein on the menu. Others bringing other stuff to go with it. num num!
I'm making maple glazed smoked salmon nuggets for new yrs eve hootenanny. Finest Fresh caught wild salmon in the world.

So there you have it. I'm going back to work.
Blessing and warm wishes to everyone.
Lets talk more next year

Hmmm...

Being a craftsman is not the same as being a woodworker. There are so many things involved in making a guitar that transcend the concept of woodworking (though that is certainly a heavy part of it). I've always thought the most important thing of being a worker of whatever type is having the attitude of trying to do it right. A raw apprentice armed with proper awareness can outperform a long time worker who just doesn't give a flip about it all...e.g. experience and the end product can many times be at odds with each other.

Brent, you have dealt with "infinitely" more pieces of wood than even a highly seasoned woodworker. Your average "luthier" has almost no experience in comparison. What you see as easily dealt with, they are going to balk at, and considering the upcharge for a master set I kind of have to agree with their view. There are so many other things involved in making a guitar than needing to ferret out the best way to deal with a given piece of wood when one's expectations are based upon having spent that money with the attitude of they're not only getting perfectly clear vertical grain and medullary rays out the yin yang, but also not having to really work the wood to bring out it's full potential (at least in the sense of the first step, which is joining the pieces...of course thicknessing and bracing is the real work to bring out the most important potential, that obviously being the sonic capabilities).

We live in a world where there is almost a trained method of ignoring the realities...YOU are quite intimately aware of what Sitka is left, and of it's quality for high end woodworking, I try to be (certainly not with Sitka, rather the woods I typically use), most simply go on with their lives and "ignore" it. Going past the concept of limited and decreasing resources, few really get the FACT that woods are a grown product and trees are subject to a plethora of factors as they grow which makes the concept of a true master grade set of wood a joke (said fictional set of wood having absolutely no runout of any sort, completely clear of all defects (real or imagined), consistent grain pattern with variations of .001%, completely uniform density and hardness, etc.). Eg. it's a piece of wood, almost all the old growth forests have been cut down and what we see now are what came after that and even the legendary old growth stuff wasn't perfect anyway, but there surely was a hell of a lot of it to cull through looking for "perfection". The point I'm trying to make is that you are fighting the opposing concepts of what the customer wants and what reality dictates. A hard battle which I too often find myself in the middle of with my line of work, which is taking the woods I'm supplied and pulling off overly ambitious expectations by those who don't have a clue as to what's involved in making their fantasies a reality.

The big point of this discourse is that your customers that aren't Martin, Taylor, Gibson are probably not going to be the master craftsmen you're thinking of, and if anything perhaps need more special attention in regards to what "quality" means.

The Asshole™

Expectations and assumptions on both sides can lead to confusion. The only way I know of to fulfill both is communication. When I began ordering in the early 1970s, there were few suppliers and you could expect the quality of what you ordered to be good, better or best. Much of the wood I'm seeing now would have been classed as "firewood". For many suppliers these days, it's more about profit than quality, and there's nothing wrong with profits if you're supplying the appropriate quality. It was Bill Lewis who coined the term "master grade" that was assigned to the top +or- 5% of tops. So, the idea of Master Grade or Exhibition Grade backs and sides is a relatively new classification. Currently. many of the "defects" that wouldn't be allowed in anyway shape or form, are considered to be "upgrade" in pricing. I have tended to buy the best I can afford in bulk, for the last 20-30 years. I like to work with the owners of businesses rather than a "big supplier". Personally, I have found that letting the supplier know what you want and expect, then letting them recommend what is best to fit the bill, gives the best result. The last order I placed was with a mill in Europe that supplies orders direct to luthiers. I asked for tops that were lightweight and stiff. What I received was ten tops that I would consider higher end for $20.00/piece including shipping. Yes, there's some irregular grain and color (minor), but they will make great guitars. So, BEFORE you order, tell the supplier what you want and let them decide what best fits your requirements. You may find a lesser expensive top will be best.

A thought: We don't hear with our eyes. When I started building, value-for-money was high on my list of needed characteristics. I got lucky with my timing and I bought a 'deal' from Alaska Specialty Woods of a flat-rate box holding as many Sitka tops as would fit, the air gaps filled with bracewood. Still working it off, and the freedom I got from not worrying about pricing has been a joy. And the soundboards have worked out wonderfully.

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Peter Havriluk

I ordered some tops from a supplier several years ago, asking for low density and good stiffness. What I got were high density tops that had been cut thin, so they were light in weight. *sigh*

Alan, we have a light density sort, we call ultra light. Most sitka sets when at dim. 23” x 9” x .180” will weigh 18-20 ounces. Our UL sort is under 16 ounces at the same dimensions.

I used to use a deflection test , and did a pre and post measurement. I can't say it helped me a lot but I did find that the braced top will give you more information than a non braced top. Wayne Henderson voices his tops to a C note. This made sense to me, in that I am taking a top and voicing it with the braces on it. After bracing and after glueing are what will tell you more . I don't tap a top that really won't tell you more than the top isn't cracked.
as an engineer I can see that the top changes once they are glued to the top, So there are many ways to build a top.
Many use density I prefer to use an after braced measurement. So what determines a good top
A grain run out to be honest master grade is RARE and grading depends on many factors but runout is BIG
B grain count per inch. I like even grain prefer 8 per inch or less no compression grain
C color Even color no streaks candle them to find pitch pockets
D stiffness with the grain


I know some will disagree some will agree but learning to match the bracing to the top and voicing a top for consistency is a skill you must master. Building a guitar is a lot of experience and learning the cause and effect relationships. Find what works for you.
One last thing HUMIDITY is so important , that can change how a top works so pay close attention to this when gluing up braces and building.

Looking forward to how others determine what works for them.

I have found great tops that had knots outside the pattern or flaws that fell out of the way. This doesn't scare me , that is what the template will do. I have seen master grade tops that were not even good firewood. So grading is subjective. KNOW YOUR SUPPLIER. Finding a good one is critical, as they are a silent partner. Learn also how you store it. Often the buyer may not store it properly and again Humidity can cause so many issues so educate yourself on how to store it properly. I hold my top wood 2 years before I build with it.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

John Hall wrote:
"I know some will disagree some will agree but learning to match the bracing to the top and voicing a top for consistency is a skill you must master."

Amen and amen. As far as I can see, that's the 'added value' in a hand made instrument that sets it apart.

Much of the disagreement comes in how you do this 'matching' or 'voicing'. There are a lot of different ways, and all of them seem to work for somebody. The important thing is having a method to get the bracing and the top working together when wood varies so much. I don't shoot for any exact pitch in the top, or pitch relationship between 'tap tones' (unless I'm trying to match a particular instrument), but look for clarity in the sound of the tap and a long 'ring', both of which signal low loss.

Here are some observations and thoughts about "runout" from the late Mr. Frank Ford, a man whose opinion I respect and with whom I agree:
http://www.frets.com/FretsPages/General ... unout.html

And here are some thoughts from the people in the Peanut Gallery - those whom the marketers have convinced what qualities are expected in a fine quality instrument:
https://umgf.com/runout-in-high-end-gui ... 92322.html

The soundboard in question when viewed in its entirety (as pictured in Brent's post) is a very nice looking top and when graded as typically done (on cosmetics) probably does fall in the "Master grade sort". If the runout disappears at the seam, it may go undetected, but still it will exist in the top. If a person wants to have a top with "no runout" they should specify this in addition to the "grade" of the top they are requesting as it is not a characteristic that is used to determine the "grade" of a soundboard.
Personally, I would rather use a less pretty soundboard with a bit less runout, but there are few perfect soundboards and I also join the edges with the least runout to minimize its appearance and put the strongest wood under the bridge.
In the age of dwindling resources we should be grateful for the tops that are available to us.

There aren't many times when everyone who has access to the same information about a controversy will arrive at a unanimous opinion. And that is unlikely to happen on this one. Two good things about this discussion:

1) the information offered by some very deeply knowledgeable and experienced builders.

2) the willingness of Brent to show up with such a thorough explanation of his thoughts and practices.

Over the past dozen years, I have purchased the majority of my tops from Brent. Some are better than others, some are great and all are very much useable to build good instruments. I've never specified a "perfect" top but if I did so, I'm confident that he would deal honestly. Not so much for some other suppliers.

Reporting Back

So I did two tops yesterday and the difference in deflection from the squared off board and the cut out top was pretty small. The difference was on the first one was .005. The second one had a difference of .025. Each top was about .25 in of deflection in accordance to my method.

So that's interesting. Cutting the guitar top to shape only made a slight difference in deflection.

Interesting…

Not at all what I expected.

Yep.

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Guitar Maker and Purveyor of the World's Finest Tonewoods
http://www.aaronhixguitars.com/
http://stores.ebay.com/A-Hix-Tonewood-a ... r-Supplies

I should point out too that the top deflection was measured with the sound hole NOT cut out. I guess that's yet one more measurement to compare next time.