David A.T.

Mastro-Keamon made reviews of these kit here. https://www.youtube.com/watch?v=EwgXGO_NEL4 https://www.youtube.com/watch?v=eDIHDcrTFG0 It seems to be nice kits. Next step is to sell the violin kit with it and a glue pot.

String behavior were described by Mersenne. https://en.wikipedia.org/wiki/Mersenne's_laws

In this video M E Russ gives his opinion regarding to the arching/corners flatness : https://youtu.be/nZF90z_pICc This has influence on the F design.

My understanding is that in the parallel design all tube are cutted only on one side. When the f-hole looks as an S, some wood tubes are cutted on both sides (blackenned area below). Parallel design should be better for the acoustic because vibration can propagate through the continuous tubes. S design might create some perturbations- but that is just an opinion, I don't have evidence, and maybe not significant.

I also tried some cooked rosin, but I lost the red color, it turned to yellow/brown

I made an other attempt. It looks better : https://youtu.be/HqudLiHXrog After 24h/48h it is still sticky. Sample 1 & 2 are trial with first receipt. Sample 2 has a Varnish + Siccativ coat on top. sample 3/4/5 is from last trial - 1 layer. n°3 is raw, n°4 is filtered one time, n°5 is done 24h after n°4. I did not put any siccativ in the varnish 3/4/5 yet. I guess it is in fact necessary for driing. Maybe second layer is necessary for more color. When i compare with current color on the instrument and a Sun ray :

thanks - before the post I was thinking this kind of shape was to be considered as a mistake. If we follow the F Hole position and arching as in OP, then we get something that look a bit like that.

I don't know how it can influence acoustic , but as the wolf eliminator are positionned few centimeters below the bottom hole I think the stifness/arching is very important in this area. I am Just wondering what way is the better one. From esthetic view it seems better when it is parallel (it is just my opinion)

I am not sure I undestood well your comment. here is what I checked on several cello. Only the the 1680 Strad seems a bit to have an angle. Also Vuillaumle was very carefull about this point.

On the side view both sides of the f-hole are parallel to the front edge ( front edge = the joint between front and ribs). This means that both f-hole sides follow their own height curve. I was wondering if the arching was not made good the 1st shot to reduce as much as possible the fluting step.

looking at Sacconi arching Cello templates, it seems something does not match because the f hole should be flat and follow the arching. is it something to be corrected on templates or during construction?

It was very small and fine segments and Leaves

Thanks for your Xp and advices. The first time I used silicate (diluted 28% to 50% which makes about 14% solution) I got this : I think I put Lime water on it (but not sure - I forgot) because it was recommended in these video : https://www.youtube.com/watch?v=Tzq4VlE5svY according to the Luthier it makes it insoluble Silicate Then I removed all the silicate/calcium at the surface and applied a clear varnish. after I got this, which was fine to me. (same as in museum, the light, the angle, and the time of the picture helps a bit for the gold rendering) For the polishing I tried this horsetail from a local supplier : it was not easy to use in fact because it goes everywhere on the plates and inside the f holes when polishing with that. I did not notice better effect than a fine sand paper. Then finally I had a not a too bad experience with Silicate and Clear varnish. I did not notice issue with humidity so far.

I used potassium silicate for the first instruments I made. I noticed that when it is much diluted the wood takes a yellow color, but when scraped it produce some white marks on the surface, then the process need to be redone. Also noticed that if too much there is a silicate film on the surface which i think must be removed. I found interesting acoustic behavior of the front and sides. But not sure that it is a benefit for the complete instrument. Hammerl wrote me to use low concentration. But low concentration might produce ribs deformation because the water increase the wood dimension and the silicates trend to freeze the shape. Then i don t think this is correct. For last project I used high concentration and a rag and then scraper. Silicate + oil gave a nice color and dried fast. But was not enough to seal because clear varnish was going through it. I would like to try linseed oil + pumice +??? next time. Looking for a formula at the moment in varnish books (also I ordered some chemistry books).

Linseed Oil + mineral can react and becomes linoleate, which is a strong siccativ. Linoleate could maybe be a good basis for wood preparation .