John Harte

Happy New Year to all!

Bill, parts of nails still seem to be present plus a later added screw.

A good idea but finding 5 willing judges per category would almost certainly be a bridge too far...

Davide, thank you very much for taking the time to comment. I do agree that judges should be prepared to stand by the scores they assign and this does happen where competitors are able to meet judges and discuss their competition instruments or bows. (At least it did 30 years ago at the one and only VSA Competition that I have entered, and presumably still does.) Having said this, I also understand why at least some anonymity might exist. Finding suitably capable judges on an ongoing basis must be very difficult and there will have no doubt been instances in the past where judges have been harassed. It might be helpful if the organisations running competitions provided more specific or focused guidelines on features that are to be considered and how they might be scored. I can well imagine judges struggling with scoring some features, especially so on antiqued instruments featuring considerable blurring of detail versus what a maker might produce in a pristine example where workmanship detail is much more obvious. And then there are areas like set up... In terms of the most recent VSA Competition, it would interesting to know whether it was one judge or all who were tough on setup. If it was the former, maybe the system for collating scores does need revisiting.

Does anyone here know how points from artisanship judges are treated? Are they averaged or do the individual judge's scores all have to reach an agreed threshold before an instrument or bow can progress into a next round or various award categories? Given that judges come from diverse backgrounds and will inevitably hold a range of viewpoints regarding almost every aspect being judged, I would think that some form of score averaging would be desirable. Scores from individual judges having to reach a particular threshold is more open to one judge skewing outcomes, effectively giving them the ability to nullify the chances of single competitors or particular groups of competitors. In other words, outcomes are potentially more able to be influenced by single judge bias. Presumably there are also rules governing various other issues including the extent to which judges are allowed to communicate or discuss various instruments or bows.

The sentence prior to Larry's quote adds context, this being “It is this question of colouring varnish which has proved the stumbling-block in the way of so many makers of the last century”. Hill's book was first published in 1902. They would have been highly aware of and seen the consequences of many and varied approaches to staining and varnishing employed by makers in England and elsewhere during the 19th century. This is the focus of their comment.

I haven't tried any of the Fantuzzi pigments but am familiar with cochineal, madder, buckthorn berry (Stil de Grain) and weld pigments from various other commercial sources. I have also made my own from the raw dyestuff materials listed here. As Jeffrey has mentioned, it is possible to mix these pigments. While I vaguely recall it being mentioned, possibly in a previous Maestronet discussion, that it is unwise to use a mixture of red pigments, I have not encountered major issues. Each pigment will have particular characteristics that should inform you as to how best to use each. Jeffrey's experience with Kremer reseda yellow is the same as my own use of their Reseda lemon lake (#36260). Having said this, I see they now sell a different variant that may well behave slightly differently. This looks more towards what I have made myself which I made in an attempt to increase both colour strength and transparency. The degree of transparency and colour value/intensity of a pigment can change noticeably according to pigment particle size. Merely stirring the pigment from the jar straight into varnish can be satisfactory. However it can be beneficial to investigate further. I have sometimes found it helpful to prepare several samples ranging from minimal grinding with muller on a glass plate through to extensive grinding. These can then be incorporated into small amounts of oil varnish and smeared onto microscope slides or glass sheet and allowed to dry. This is a very quick and dirty approach which gives at least some idea of how far and where to take things in terms of that particular pigment. (I also use other approaches but this so far seems the most simple test.) While it can be challenging making your own pigments, it can result in many and varied outcomes including very positive ones. The range of colours possible from individual dyestuff materials can be surprising. Following on from Jeffrey's mention of making his own cochineal lakes, below are examples of a couple of my own recent efforts compared to an older more purple example. As you can imagine, each of these results in a different colour outcome in varnish.

Hi Mike, Figure 98 more clearly illustrates the general concept even though, in this case, a cello profile is involved. The (accurately produced) widths of the borders and the points at which they begin to deviate are important. I would also again suggest that you carefully study the image that Davide posted. Take a very good look at what happens to the C bout rib line as it transitions from the mould outline onto the corner block profiles. Note the corner block curvatures and how at the transition point between mould and block, the blocks sit proud of the mould profile. To emphasize this point, below is a rib tracing from an open c.1714 Strad that I have placed over the G mould outline. Note what happens as the rib outline transitions into the corner block regions and also what the actual shape of the corner block profile has to be to achieve this. I imagine that you have a CT scan of the Titian rib outline. This may be on the poster and, if not, can be found amongst the Strad3D data. This should provide some sort of basis for laying out corners that look more towards what you see on the Titian.

Mike, there's a lot of excellent advice regarding corner shaping given above. At the risk of stating the obvious, in your case the back outline is following your rib outline which in turn is established by your mould and block outlines. Corner block outlines are an important factor in how corners end up looking as is well illustrated in Figs. 49 and 98 in Sacconi's book “The Secrets of Stradivari”. These drawings clearly show the way in which Strad plate outlines in corners generally follow and then deviate from rib/corner block outlines. For anyone making a Strad pattern, I would suggest largely ignoring the corner template shapes associated with each of Strad's moulds. If you were, for example, making a PG pattern instrument and wanting to produce corners of similar profile to those of the Messiah I would suggest closely studying the image of the Messiah rib outline and blocks superimposed on the PG mould that Davide Sora has posted here: https://maestronet.com/forum/index.php?/topic/339864-the-pg-mould-does-not-fit-the-messiah-poster/ Adding a plate outline over this and applying what Sacconi has suggested plus fudging other outline details (e.g., what often happens where the C bout rib joins the upper corner block) should result in corner profiles that are in the direction of your Messiah corner photos.

Davide, I'll see what I can find out regarding 3B being the only one recommended for wood joints. If anything can happen, it may take a while. The 3B does seem to have a longer tack time than other glues I have used. Even so there seems no problem pulling threads between thumb and first finger as the glue does tack. What you have been using has very similar viscosity and jelly strength specs to the current Special 1 glue so maybe this is more suitable than the 3B for the major glue joints??? I will let you know if I find out anything.

Apparently possible. Mexican cochineal contains carminic acid whereas Kermes vermilio contains kermesic acid. If I recall correctly, Polish cochineal contains carminic and components of kermesic and flavokermesic acids.

Davide, thank you very much for your additional comments and extra material. What you mention regarding higher gel strength and the possibility of this equating to longer and less fragmented protein chains potentially resulting in greater holding strength may well be the case. Whatever the case, the Glue Grade Selection section beginning on page 8 in the first attached below certainly states that the higher jelly strength grades (grams) are the strongest. I am not sure what the Jelly Strength actually indicates as it involves a standardised dry glue weight and water quantity/ratio for all glues being measured. Given that we don't use the differently rated jelly strength glues like this, i.e., we vary the glue to water ratio, I wonder what the actual relative strengths are. In my own tests I found the Nikawa 3-B glue bonds a lot stronger than the Bjorn 315 that I tried in spite of expecting otherwise based on the relative stated gram/jelly strengths. I wish that I knew more about the manufacture of the various grades and at what point each was extracted in, for example, the process outlined in page 2. I imagine that the first extraction might have the longest and least fragmented protein chains but this could be quite incorrect as this may involve the most easily broken down protein material. Different manufacturing processes might also result in different outcomes. In the second attached, Cowskin Japanese glue 3-B is the only one of their glues that is specifically mentioned as being suitable as an adhesive for wooden parts. With reference to the same glue, Cremona Tools also mention the following, presumably from the manufacturer: “Nikawa is suitable for all wood works and restoration of wooden parts. In the work of repairing/reproduction cultural assets and properties, Nikawa's use can be classified roughly into two applications - as a binder for coloring pigments or as an adhesive for wooden objects. We recommend the concentration of the dissolved Nikawa glue used as an adhesive to be: Water : Nikawa = 6 : 4 (ratio by weight).” I remain confused, but that's not unusual... 40 Centuries and Still Holding.pdf Nikawa Shop Glues.pdf

Thank you Andreas for the translation.

Davide, thank you very much for your reply which I much appreciate! This is all very helpful! I'll see if I can find out more regarding the Amanosan 1-S. I have something like 2kg of Amanosan/Nikawa 3B that my daughter in law has kindly acquired for me on various trips back to Japan. I have only thus far used it for gluing cracks and an open centre joint following a series of trial tests. It seems to be a very good glue with a noticeably longer gel time than anything I have used in the past. My only concern has been the listed gel strength but maybe this doesn't ultimately matter given the dilution ratio involved. (The ratio I have started out with has been 1:2 but a little further thinning has generally been involved so would have ended up close to what you have used.) I'll see if my granddaughter can translate the Japanese text this weekend. If not my daughter in law or son should be able to. Many thanks again!

Davide, have you ever tried any of the Japanese Hide Glues for these joints, e.g., Amanosan 3B or Harima? If you have, I am interested in any comments that you might be able to make. The Amanosan (Nikawa?) in particular appears to have a very different gel strength to the glue you mention using in your video.