JacksonMaberry

In the Hill's books, and elsewhere in the British violin literature, spruce is somewhat confusingly referred to as 'pine'. Stradivari invariably used true spruce (piecea spp.), no matter what anyone else called it.

I have not tried this and cannot therefore make any case for or against it.

In my other post you commented on, I outlined two tests I have made to assess the durability (and thereby in a sense stability) of the varnishes I prepare and use. The results were very good. I don't understand what you're getting at. Some makers want to use a varnish as close to that of the ancients as they can, and that desire leads to a number of approaches. Considering that classical cremonese instruments have been shown to have varnishes that are susceptible to chemical and physical decomposition over time and exposure, it is not unreasonable to desire today varnishes which exhibit these same characteristics. Other makers, myself included, are less concerned with historicity and want coatings that are aligned with their personal aesthetic preferences, methods of application, and ideas about durability. Neither of these two mindsets are invalid.

Could you please clarify what you mean in this case? Do you mean "why not linseed oil alone as a resistant topcoat"?

That's the thing, however. People keep offering valid reasons for why they prefer not to use poly and you keep hammering on it as though you've only been told "I just don't want to!". That is not the case. If you are passionate about the use of poly in this application, why not run some experiments of your own and get back to us? If I recall correctly, you work in the sciences. Why not approach this scientifically?

Respectfully Dennis, if the Brescian and Cremonese instrument makers were concerned with constructing and using 'French Curves', why then are they not 'Italian Curves'? Is it safe to assume that, if the tradesmen of northern italy were interested in and capable of this particular geometry, that the academics of Renaissance Italy were even moreso? Belief need not enter into what is observable directly. For his part, Beard has exhaustively displayed over the course of many years how the precise contours of extant important instruments can be recreated in detail with a few simple rules.

The jury is still out, with regard to real world use. In my own tests, which are kind of icky, it stood up well. In one test, I "augmented" saliva with lactic acid and table salt and attacked the varnish with it on a cotton cloth repeatedly. In the other, I worked up a natural sweat and again attacked the varnish with it on a cloth. In both cases, the film was unchanged. If it proves to be susceptible over time on the instruments out there, I will probably go over the top of the last color coat with a thin coat of Amber varnish, as Joe has mentioned.

Valid reasons have already been given for the fact that polyurethane is not used for this application in serious luthiery. "First, do no harm" applies as well to fine violins as it does to medicine. The sheer variety of decorative and protective coatings available is, in part, because of how different properties are valued for different applications. Violins are not guitars. It is arguable that polyurethane and nitrocellulose are not the best coatings for guitars, either, certainly from an acoustical standpoint. There is no reason not to use poly on a plant bench or a tortoise enclosure. Violins, especially ones already finished with a very different coating, are another matter.

For a while I was using (redacted) commercial varnish, and the instruments in question would be fine until sweated upon, and then the varnish became sensitive even to water when cleaning in those areas. I am more than open to the possibility it was my error in application and curing rather than an inherent property of the varnish. Since switching to my own rosinate varnishes, I am not having this issue. Hoping to hear back from The Scroll today about their printing my paper, given that today is the submission deadline.

Silver fir, larch, and canada balsams can all be made into fine varnishes.

The persistence of the cross arching "rule", the flexibility of the system, and the results I've gotten from actually using it are compelling. To those that wonder at the utility of Beard's research, why not take it to the bench before you decide whether or not it works? I say the same about Darnton's cycloid half templates. If you haven't given it a go, what's stopping you? I'm planning to make and try some of Dennis's templates, and if they get me where I want to go faster and better than what I'm doing now, I'll switch. I have to eat, which means I have to make. If any method doesn't produce quality results efficiently, it's not for me. But if I haven't tried it I can't say whether or not is has value.

I'd have done it! Next time, perhaps

@Jim BressBress makes a fine solvent free varnish. Perhaps he'll share his thoughts. I have an article coming out soon and once it is printed will share the technique on MN as well. I prefer a 3:2 oil:resin ratio myself for a variety of reasons and especially absent solvents a fatter varnish should brush easier.

https://www.ebay.com/itm/233340106950

If you can get access to a print or cast of a scroll you admire, you can easily make your own "story stick" based on it, as well.

Agreed - this is where you and Beard ultimately agree. And I appreciate the attention you place on inflection point. I concur that it's a critical factor

I've used full arch and half arch templates, and I've used Beard's technique. The latter, for me, is significantly faster and gets me where I want to go. It allows me to get in the ballpark working whole arch at once, then turn off the lights and go to point source by eye for the finishing touches. Thank you, Beard-Sensei.

Considering the risks, I don't blame you.

I don't know about rust/ iron acetate, but oxides of iron are generally unstable unless measures are taken to stabilize them. For example the case of iron rosinate, where the ferric ions are bonded to the abietic acid molecule. Iron rosinate properly prepared is not only an intense colorant but a profoundly effective drier.

Their planes are just gorgeous. If I ever buy a larger jointer it will be one of theirs. I wish they made the radius plane in one or two smaller sizes, but that is undoubtedly a lovely tool at a very reasonable price.

I trust your testing. I just don't have much cash, so I get by on what I've been given or bought cheap, for the most part. Always appreciate good tools, however. Maybe someday I can buy some of yours. Until then, I'll keep on as I have been. What kind of workman would I be if I blamed my tools?

Price to performance ratio as regards ability to take and retain an edge is very good. Not as good as pmv-11, but less than half the price where applicable

You and me, both. It's fun, anyway.

No sweat, happy to share what little I know. I'm working with The Scroll to print my paper in the Spring issue next year. I've never been particularly concerned with what past luthiers have done with regards to wood finishing. My aim has always been to arrive at an easy, reliable approach that suits my aesthetic preferences. What I've come up with, thanks to Michelman, McIntosh, and my friends and colleagues, ticks all those boxes for me. With cooked rosinate oil varnishes the way I describe them, you can modify any number of parameters, such as the ratio of distinct rosinates or resin to oil to change virtually any important property; color, durability, elasticity, etc. I'm certain it's not for everyone and I have no desire to cram it down anyone's throat, but it's a useful option for anyone who wants it.

Damn, might need one of those double convex once I get to that cello... Thanks D!