So here is my experience with the Old Wood ground and varnish system. Note I am essentially an autodidact beginner luthier, having made my current violin after a 25 year gap from making several in the remote past. As you will see, I made several mistakes, from which I hope to learn. I detailed my experience as these “notes to self’ to improve my next effort, so take them for what they are worth; I make no claim that any of my notes will give a good result for anyone else. Maybe some of the pros can add suggestions about what I did right and wrong. Someday I would like to attend Joe Robson’s workshop, but for now I am on my own. I do know Joe’s first rule of varnishing; “First do no harm.” I had to learn that lesson a few times as below. I should have run through the entire process on a trial piece of wood, but I didn’t have the patience to go through 4 weeks of trial finishing, and I am not sure that would have averted my newbie mistakes, especially given the convoluted surfaces of the actual instrument.
I tanned the violin in the UV box for two weeks. Mistake one: I thought I had checked it over pretty thoroughly, but I should have been even more diligent. The slightest irregularity in the surface or errant spot of glue will become glaringly apparent as the process goes on.
I applied 2% technical gelatin as instructed. This was pretty easy.
I used the foundation color Italian Golden Ground A/B. The A phase went on pretty easily, and I made sure not to over-rub it with the sponge to preserve the gelatin layer. After 8 hr of UV I did the same with the B layer, which only needs to air dry. After air drying, I noted on the back of my violin a lot of spots, like freckles. Not sure what to do, I used a wet cloth to rub it out and the B layer freckles came off. I was concerned that I might have rubbed out the technical gelatin, but in retrospect that does not seem to be much of an issue. Note to self: Don’t put too much of layer B on, but if you do, you can gently rub off the freckles.
I then applied the Old Wood refractive ground. I hand rubbed it with vinyl gloves, and this went pretty easily. Mistake three: in the process of rubbing down the coat, you have to dab your glove on a cloth periodically. I didn’t ensure that my first cloth was totally free of dust and lint. Hence, I transferred some extra tiny debris on my finish. Before putting on a second coat of refractive ground, I endeavored to pick out the defects. Mistake four: Most of this went OK, but I obsessed over a little black dot on the top and worked at it too much, leaving a small divot in a summer growth line. Mistake five: I decided to fill the divot in with extra refractive ground, and put painter’s tape around it to only expose the divot. When I pulled the tape up, small pieces of the prior ground layers came up, leaving the bare wood. Sadly, I had taken a small problem and created a larger one. Fortunately, I was able to repair that with more A/B ground, and the tiny black dot is still there (just in front of bridge on left side in the pics). I did learn from this that 1) the ground is very delicate and 2) It doesn’t penetrate the wood very far at all.
I then hand rubbed a coat of Doratura Minerale. This was thick stuff, which can be thinned a bit with the special oil that comes with it. On my next instrument, I will probably omit this step, because for me it filled in the winter coat reed lines to some extent, and the refractive ground alone is quite nice as long as you apply it carefully. I probably should have followed the instructions to rub the cured Doratura with odor free kerosene to get the mineral particles off the surface, but I used 2000- grit sandpaper. (note to self; follow ALL of the instructions).
I put two coats of Old wood yellow varnish on next. It looks dark in the tray, but after you rub it on, it looks clear. The violin looked very pretty, but colorless. I then did one coat of dark brown and one coat of dark brown with red mixed in. It still was not very dark. I knew I needed more pigment.
I toyed with mixing artist oil pigment in with the varnish but by now I was very wary of creating my own disasters, so I bought the $150 brown/red natural pigment from Old Wood. I mixed this with dark brown and applied it. Getting a highly pigmented coat on even was much more of a fuss for me, but I was able to do it. I then followed that with two coats of amber varnish. Here are some things I learned about hand applying the varnish: (yes, more mistakes)
A little bit goes a long way. I put small amounts in an artist’s tray which worked well.
A couple drops of Old Wood thinner may help with the spread.
Rub in with circular motions, but I found on the top the final motion should be along the reed lines, and on the back in the direction of the curls. Check for color uniformity looking straight at it under bright light and check for surface defects by looking at reflective light from an angle.
Get it on a section, then leave it alone. Trying the fix minor defects after the varnish has set will result in roughness of the layer.
My routine was back, top, sides, edges, then scroll.
Use a fresh clean cloth to dab extra varnish off your gloves. Slightly wetting the cloth with the Old Wood thinner may help, but don’t overdo that.
A stiff bristle brush is a must for getting pooled varnish out of tight spots. Another small brush is helpful for coating the inside of the F holes and other small spaces. Do the F holes just before rubbing that part of the top.
Between coats, you can rub with fine abrasive, but only to remove tiny dust particles. It is really easy to rub right through the previous coat, resulting in uneven color etc. I used 2000 grit paper with brief wet sanding, almost no pressure.
Another error: I should have paid a lot more attention to the joints between the plates and the sides. I assumed that the varnish would cover for any small defects, but it would have been better to make sure that these joints were totally clean and then make sure not to allow varnish build up at the joints, which just looks sloppy under magnification.
I used pumice then rottenstone to rub out the varnish, but this resulted in too matt of a finish for me. I rubbed an extremely thin layer of amber on top of that, and then very VERY gently went over that with rottenstone only, and that gave me the sheen that I like.
The series of pics here first shows the violin with ground, then the finished instrument. I had a lot of trouble capturing the actual finish, which is really quite nice. Tangential lighting eliminated bothersome reflections but then made the finish look artificially strange and blotchy, so I have posted several lighting options for the top and back. The highly reflective back picture shows the true character of the finish the best. The wood for the back of my violin was very inexpensive, so the fact that only part of it shows curl is a true reproduction. The part that does have curl has nice chatoyance.
The sound: when newly cured, the high notes on the violin seemed to me a bit muted, but with a few weeks of further setting, the violin is coming back to the bright or even better tone that it had in the white. The varnish is not yet done curing.
In case it is not clear, the pics (submitted with lower resolution IAW instructions) show
1. Front and back after ground application, bare wood for reference
2. Final varnish front
3. Back without glare, tangential lighting
4. Back with glare, direct lighting