Contorno dei bordi parte terza - Finitura del contorno della tavola 

Grazie mille😊

@@DavideSora Grazie a Lei, Maestro. Stia bene - A.C.

Gracias por las palabras amables. Si necesitas información o medidas que no ves en los videos, no dudes en preguntar aquí en los comentarios del video o enviándome un correo electrónico. Tengo muchas preguntas que responder, pero trato de encontrar tiempo para responderlas todas. PD: No hablo español, uso Google Translate y espero que se traduzca de una manera comprensible.😊

@@DavideSora Maestro gracias por el amor que tiene usted como hacedor y constructor de violines, hace que este mundo sea mas maravilloso. Se tradujo perfecto con google, cada vez traduce mejor. Ya voy a preparar algunas preguntas, tengo que ver sus videos muchas veces para comprender bien el trabajo ya que es bastante diferente a trabajar guitarras y no es tan fácil como parece, no creo que mucha gente pueda hacer su labor tan bien como usted, pero estamos para aprehender.

🙂

The coarser (the black ones) I use are old Sandvik Sandplate (Swedish), but the production was interrupted many years ago (I bought a small supply then ) The finer ones (the silver ones you show in the photo) are NT Dressers that can be found on the market in small adhesive sheets : www.cremonatools.com/nt-dresser-ps-11p-fine-0-2x54x80mm.html The same company (NT Dresser) also produces coarse-grain ones as spare parts for their line of tools, they also produce simple flat sheets but they are not easy to find, the more available spare parts have bent edges and screw holes and need some adjustments to make them work : www.amazon.com/NT-Dresser-Sander-replaceable-M-20GP/dp/B0034YQWT2 A recent alternative is this "sharkskin" from StewMac, I've never tried it but seems promising, a little coarse perhaps : www.stewmac.com/Luthier_Tools/Tools_by_Job/Tools_for_Sanding/StewMac_Sharkskin_Abrasive.html I remember that there were some discussions on the forum on this subject, but I do not recall when. To adapt them to the curved tools it is necessary to pre-bend them as much as possible with the help of a steel rod (I use the scrapers burnisher) carefully without causing angled folds, then I glue them with cyanoacrylate keeping them clamped for a long time with strong and tight adhesive tape, otherwise with the spring effect of steel it is difficult to keep them glued. PS You can also find some useful information on this topic on Maestronet forum : maestronet.com/forum/index.php?/topic/339885-sandvik-sandplate-substitute/

I assume your glue has a fairly low gel strength (I guess around 140), otherwise a 1:2 ratio would be too dense for most gluing. But if that's the ratio you use for normal gluing with your glue, for edge glue size I would try at least 1:4. The glue size is not a structural bond, it is not critical so it is always done by eye, the yardstick is how the glue absorbs, particularly in the end-grain area of ​​the spruce: I have to insist three or four times in those areas before it stops absorbing, while in the other parts 1 or 2 passes at most are enough. The final result, after the glue has dried, should be a saturated but not shiny surface. If a thick layer of shiny glue forms on the surface, the glue is too thick. If it absorbs too much and you have to apply many coats before it stops absorbing, it will be too diluted. However, if you insist until the absorption stops, you will get a properly sized edge anyway

@@DavideSora Thank you for your advice! My glue is 220 strength. I have found references recommending a 1:2 ratio by weight for that strength, so I am confused why you're saying it would be too thick. But of course there are always different opinions to be found. I'm not always sure who to listen to.

@@GarthShoemaker 1:2 ratio by weight will certainly give you strong bonds, but it could be too viscous for some tasks, or too thick if you do pre-sizing, so without much glue absorption. This is just to say that it really depends on the characteristics of your glue, not only on the Bloom number (gel strength) but also on other parameters depending on how it is produced, and which are rarely indicated by the manufacturers. Then, it is a natural product, and a certain variability is inevitable. I use 300/350 glue, and at a dilution of 1:2 it would be unusable, I use it between 1:3 and 1:4 for strong bonds (central joints) and between 1:4 and 1:5 for structural bonds such as the neck and bass bar. For everything else I dilute it by eye, I estimate from 1:5 upwards. But these dilutions could be too much for other glues, the only truly reliable way is to do some tests at the various dilutions with the glue you have, and together with a bit of experience after a bit of use you will be able to obtain the appropriate dilutions and the appropriate viscosities to obtain strong joints with practically zero thickness of glue. At the same time you will become familiar with the evaluation by eye based on how it moves in the jar when shaken, how it drips from the brush or on the edge of the jar, and the sensations it gives when rubbing it between the fingers. Too much thickness reduces the glue's hold, which is why it is important to understand the right balance between dilution, ease of use, and holding power.

The black ones are medium and the silver ones are fine grit. The coarse ones are useless for this type of work.

Thanks Davide, much appreciated.

Yes, the purpose of the glue is precisely this, to consolidate the wood and make it more homogeneous under the cutting of the knife. However, it does not completely solve the problem and spruce is always a bit problematic to cut, especially if it has a wide grain. Sometimes cutting the hard grains first (the dark ones) and also cutting them against the grain can help. A super sharp knife is imperative.

@@DavideSora Thanks for the great videos and for the replies!

@@DavideSora Hello, thanks again for your great video. I'm revisiting this comment/question/reply from two years ago: You apply hide glue to the platform. Originally I was asking if this was to help when you are cutting the 1.3mm wide purfling channel. However, before you mark and cut the 1.3mm purfling channel, you refine the platform with a rasp, and then you cut the "fluting" channel (or re-curve channel) - which is the subject of the video titled "Tavola di violino - Scavo del canale della sguscia" (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Kb_Cs7ym-5k.html). So, the glue is to help cut the 7mm-11mm wide "fluting channel" and not the 1.3mm "purfling channel"? Should I re-apply the glue after the refining the platform with the rasp? Should i reapply again before marking the 1.3mm wide purfling channel?

@@tpistor I usually don't, unless the spruce is very low density and with very wide grain, which I try to avoid. I also prefer not to put the glue back on to avoid residues that could cause glue ghosts under the varnish, although sometimes these glue ghosts are also seen on some Stradivari. One thing I do is to insist a lot with the glue on the outside of the edges so that it absorbs as deeply as possible putting diluted glue until it reaches saturation (stay on the surface), it usually penetrates enough and strengthens the edges well.

I use casein sealer before varnish, I never had glue ghost problems

About what?🙂

About the varnish process? Ground and varnish layers? Greettings

Grounding and varnishing is a very undefined and definitive field and it is difficult to make videos that are inevitably taken as definitive in some way, whereas these aspects are constantly evolving, so I'm a little hesitant to "fix" such a process in a video. Anyway my intention would be to cover the entire construction process, so sooner or later I think I will.

Davide Sora its ok thank you!!

Si, sono lamine di metallo simili a micro-raspe prodotte dalla ditta giapponese NT Dresser. Una volta le produceva anche la Sandvik con il nome di Sandplate (che sono quelle nere che si vedono nel video) ma non le produce più da anni. Adesso conosco solo la NT Dresser che le produce in tre grane diverse : fine, media e grossa, io uso solo fine e media. Si può usare anche la cartavetro 120 e 320 tipo quella rossa per le levigatrici a nastro ma è meno efficiente, si consuma e non dura moto, invece le lamine sono praticamente eterne. Se leggi le altre risposte spiego anche come si incollano (con l'attak).

molto interessante e sei stato molto dettagliato maestro, ora vedo se li trovo perchè sono molto interessato e sono molto utili queste lamine a differenza della cartavetro che bisogna sempre scollare e reincollare sulle dime...per chi fosse interessato io uso una colla alla pari dell' attack e si trova in negozio Eurospin a 0.99 cent anzichè i 2 euro forse piu dell' attack e vi assicuro e identica come caratteristiche, la uso proprio per incollare cartavetro e altre piccole cose...grazie ancora maestro

Si si, io parlo di Attak o Superglue perchè per molti sono sinonimo di colla cianoacrilica e non sanno che si chiama così, ma sono entrambe solo marche commerciali. Anche io non uso l'Attak che è eccessivamente costoso ma una colla cianoacrilica perfettamente equivalente che compro a meno della metà del prezzo dal ferramenta, si chiama Dexcyan, ma qualsiasi altra marca funziona uguale.

🙂🙂

Si, si vede nel primo video della serie : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hJkWcu1ir5w.html

Grazie! Prima devo fare i video degli spessori, poi farò anche quello della catena, devo solo trovare il tempo

grazie mille Maestro per aver risposto al messaggio, spero di tornare ancora a cremona e di conoscerlo personalmente, seguo le sue tecniche e i video uno a uno mi piacciono tutti, mi congratulo per il suo lavoro impeccabile

Un abbraccio dal maestro Venezuela

Grazie mille maestro

I buy pure casein powder but you can make It starting from milk or from no fat cheese (quark)

The coarse ones are old Sandvik Sandplate, no longer in production, the finer ones are NT Dresser, a japanese brand. However, you can find both grits from the company NT Dresser. You can find something from Cremonatools (the silver finer ones) but I think you have to do a web search to find the coarse ones (black). I use cyanoacrylic glue (like Superglue or Attak). Glue the metal plates is a little tricky, you have to make a cut in the wood, make a bend in the metal plate, insert and glue that bend in the cut and wrap the metal plate around the tool spot gluing it in some place and gluing the end keeping it pressed well for some time (15 minutes at least) in some way, using tape or someting else. Cheers to Ting Ting😊