JacksonMaberry

What I wouldn't give for a week in your shop...

Michael Darnton's use of the half template based on curtate cycloids (as I understand it from his writings and secondhand from Richard Barnes, one of his students) is the most agreeable template method I have encountered due to its overall simplicity and flexibility. For me, once I understand some key wood properties like density and some notions about longitudinal and cross grain stiffness, I choose a max long arch height, derive the remainder of the long arch using simple geometry by means of dividers, then derive the cross arching from the long arch to the inflection point (channel boundary) again using a simple geometric rule applied with a dividers. At this point, I can punch a dozen and a half guide marks and get to hogging. Half an hour of brainless math, an hour of carving, and I'm ready to cut soundholes and graduate. I finish margins, purfle, and carve the fluting with the box closed. It's pretty efficient.

Dennis, I feel terrible because despite my best intentions I seem to have initiated a 'pile-on'. I want to commend you for what took a lot of effort to provide guidance for yourself and others in the arching process. There are so many paths to a good result in this business, and have been for a long time. Please don't be discouraged. I have made my personal feelings on templates clear, but want to reiterate that I have no contempt whatsoever for those that use them. I have only admiration for fine luthiers regardless of their system. I invite you or anyone else to come spend a week in my shop and we can share ideas and techniques. I'm here to learn and want to keep an open mind always. J

Outsider/non-traditional perspectives help refresh any field. Thanks, Don!

I think you'll find we are capable of making these ideal shapes, which is why we can make a living.

In the case of albumin and gelatine, the hygroscopicity puts me off a bit. In the case of casein, I don't understand it well enough to feel comfortable using it and, due to its pH is known to react with anthraquinones like alizarine and purpurin, as from madder. Then there's the Echard findings, where protein coatings seem not to have been found. I don't have strong feeling about how anyone else gets finishing done, it's just a preference at this point.

Is that the Pete Prier method Jacoby talks about?

Personally I avoid proteins. I have tried dozens of things and continue to experiment, but right now I'm sold on Joe Robson's ground system. I use it a little differently than he recommends - I get a good heavy tan on the bare wood before I start applying the coats. As I understand his products, what you end up with is a complex of resins and a tiny bit of oil (as part of the last step, the "ground varnish) entirely inside the upper few microns of the wood surface. I have found it to be an idiot proof system. Going right on top of that with as richly colored a varnish as you want will not burn anything.

I am a Stainer admirer, to be sure. I have handled two of them, but have not examined any under UV. From what I could discern under natural light from the wear, it seemed pretty similar to other fine violins of the period I've seen - some sort of ground in the wood and a colored varnish above it. But I am not a copyist, and I am not a seeker after the "original recipe". I have worked hard to understand the geometric rules that govern the arching, how wood selection and grads play into that calculus, and how the bassbar and setup maximize the potential of the corpus. When it comes to the largely aesthetic concerns of texture and wood finishing process, my aim is to have the instrument look like I made it, not Stainer.

Hang in there, bud.

It doesn't get much simpler than melting rosin in a base, precipitating with a salt, and cooking the precipitant in oil, but whatever floats your boat.

I did not use the term 'ignoramus', nor do I think it applies. It's well established that literacy rates, among men alone, were staggeringly low by modern standards in Renaissance Europe. One doesn't have to know how to read or write to be intelligent and skilled. But literacy does affect the transmission of knowledge, and so I turn to Don Noon's reply to agree with the instructional model he hints at. Lastly, while this is a perennial hot button issue here, I too would like to point to the lack of extant templates and say that they are not needed and frankly cause the work to go so much slower in my experience than punching guide marks and just removing everything that doesn't look like an arch.

If we're fixing colors with metal salts, why not just make rosinates?

Dennis, I have followed your various threads with interest. You have clearly devised a workable method. I hope that you will take this gentle criticism in the spirit that it is intended. To my mind, your system seems unnecessarily overwrought. I am generally of the opinion that the simplest solution is the best, for the sake of efficiency (a concern for me because new making is my sole occupation) and for the sake of the appearance of fluidity and effortlessness that fine sculpture offers the senses. While I believe that your arching technique is overall sound, I think it's important to attempt to put yourself in the shoes of semi-literate 16th century Italians. What tools did they have? What level of mathematical knowledge did they possess? My friend and colleague @David Beard has explored this extensively and put forth one possible reconstruction of the Cremonese working method that is very simple and compelling. Other luthiers, such as Roger Hargrave have written at length along this lines also. I am sure that you have made a thorough examination of the existing literature, but on the off chance you aren't familiar with their works, I believe you would enjoy reading them, if for no other reason than to compare them with your own approach at the bench. My best, sincerely, J

If my lightbox is running, the hygrometer will turn the atomizer on or off as needed to maintain a range of 40-50% RH. Tanning, curing, or if I crawl in there to synthesize some vitamin D (kidding on that last one). I appreciate that insight, Mark. These are very cheap, can be e-cycled, and if mineral deposits are of concern I see no reason distilled or RO water shouldn't be used as per your suggestion. You could also modify the pH of Distilled/RO water with a base, but then you're probably back to the issue of deposits. Maybe a 0.25% solution of KOH would be ok, I don't know. Edit: if deposits are seen to develop (I haven't seen such yet, but my water is good and I've only run it for a couple hundred hours), wiping the reflective surfaces down with a cloth dampened with dilute CLR should address the issue.