Posts Tagged ‘pine resin’

Beginning the Finish

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Beginning the Finish

Pre-varnish Scraping and Shaping

Before any finish materials can be applied, the wood has to be about as perfect as I can make it: so I scrape it to its final shape, then dampen it with coffee, to simultaneously raise any fibers that had only been flattened by the scraper blades, but not smoothly sheared off, and, hopefully, add a slight “tan” to the wood, while doing no harm.

Thus, having removed the fingerboard (which had only temporarily been installed) and having applied two coats of coffee, allowing the wood to dry between coats, and having sanded lightly, all over, with 400-grit paper, to remove the raised fibers, and any excessive “corduroy” effect, the instrument went from looking like this:

Shaping complete, but wood un-treated.

Shaping complete, but wood un-treated.

 

To looking like this:

Coffee-stained, and sanded with 400-grit.

Coffee-stained, and sanded with 400-grit.

 

Then it is time to begin the real finish: I first coat the wood with a coffee-suspension of very fine, powdered gypsum, hoping to add more color as I fill the grain with the gypsum. I vigorously rub this suspension into the wood, hoping to encourage the tiny particles of gypsum to actually settle into the pores of the wood, so as to fill them, and to slow down the absorption of varnish. It is considered undesirable, in general, to have the varnish really soak into the wood, as it tends to dampen the vibrations that make the sound. Some varnishes are more detrimental than others, but this is something I learned by reading Roger Hargrave’s notes. He is a world-class expert, so I tend to believe him that this is a good idea. I try to remove as much as I can of the excess mineral “ground” before it completely dries, rubbing hard, with a rag, but any that has settled into grain irregularities, I simply skim over, and leave it there.

So, after the gypsum has been applied, it looks more like this:

Mineral ground applied, front view.

Mineral ground applied, front view. A little darker color, and the grain is more obscure.

 

Back grain quite obscured by the gypsum.

Back grain quite obscured by the gypsum. That will clear up entirely, with the application of the sealer.

 

The sealer locks the gypsum into wherever it has been lodged, and clears the obscurity, making the gypsum completely invisible. The sealer I am using now is a concoction of pine resin, turpentine, and alcohol, with a little yellow tinting. The turpentine and alcohol evaporate, leaving the resin in the wood.

Sealed Front.

Sealed Front.

 

Sealed side.

Sealed Side.

 

Sealed Back.

Sealed Back.

 

After the sealer dries (a day or so), I begin applying the various coats of varnish: the first two or three coats are fairly yellow varnish, but after that, I begin adding the colors that will characterize the finished instrument.

Front with yellow varnish.

Front with yellow varnish.

 

Back with yellow varnish.

Back with yellow varnish.

 

From this point, forward, the instrument will become increasingly darker, leaning toward reds and browns. Ultimately, I will try to emulate the look of the 1715 “Titian” Stradivarius violin, after which this insrument is supposedly modeled. We will see how it turns out.

 

Thanks for looking.

 

 

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Varnish Process

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Varnish Process

Sealer Coat is Dry: Start Varnishing!

Since the sealer was dry, I gave the violin a careful rub-down with worn 400-grit paper, and began to add varnish. I am using a spirit varnish, the first coat of which was a yellow varnish, which I had actually hoped would be a little more “amber” in color, but I think it will be OK.

First coat of varnsih on back plate.

First coat of varnish on the Back plate.

 

1st coat varnish on side.

First coat of varnish on the Side.

 

First coat, Front plate.

First coat of varnish, on the Front plate.

 

2nd Coat of Varnish

The first coat of varnish was really only intended to lay down a yellow under-coat, and I am satisfied that it accomplished that purpose. From here on out, though, I will be trying to lay down more color in the areas indicated, to try and match the original after which I am modeling this violin. So, here are coats two and three. Notice that I leave some areas light, as the original violin has fairly severe wear in those areas.  (If you are interested, click here to see photos of the original.)

2nd coat of varnish.

2nd coat of varnish, on the Front plate.

 

2nd coat on side

2nd coat of varnish, on the Side.

 

2nd coat on back.

2nd coat of varnish on the Back.

 

3rd Coat of Varnish

And, a third coat, in the same manner:

3rd coat, front.

3rd coat of varnish, Front plate. The light was a little better, so it looks brighter.

 

3rd coat, side.

3rd coat of varnish, Side view.

 

3rd coat, back.

3rd coat of varnish, Back view.

 

4th Coat

The first few coats are thin enough that it is difficult to see the changes…but it is gaining a little more color and gloss.

4th coat, front view.

4th coat of varnish, Front view.

 

4th coat, side view.

4th coat of varnish, Side view.

 

4th coat, Back view.

4th coat of varnish, Back view.

 

5th and 6th Coats

It is pretty obvious, now, even on the ribs, that certain areas are getting less color added. As I explained above, those are the areas that typically get the most wear, so, to imitate the wear patterns on the original instrument, I am minimizing the color added to those areas.

Also, I have been making the varnish coats quite thin, right now, trying to adjust the color early, instead of trying to fix it later…so, from here on, I posted the pictures as I saw relevant changes, rather than after every coat of varnish. I also switched over to a more intensely colored varnish for the 5th and 6th coats:

6th coat, front view.

6th coat of varnish, Front view. Lots of changes still to come.

 

6th coat, side view.

6th coat of varnish, Side view.

 

6th coat, back view.

6th coat of varnish, Back view.

 

Starting to look closer to what I had in mind. 🙂

 

Final color coats, and two clear coats

I gave a careful look to the poster, again, and tried to get the “wear areas” closer to the original. It is still far from accurate, but it is beginning to at least have the “flavor” of the original. My color is still too bright, and some areas still too light, but it is getting closer.

Front, nearing completion of color coats.

Front, nearing completion of color coats.

 

Side, nearing completion of color coats.

Side, nearing completion of color coats.

 

Back, nearing completion of color coats.

Back, nearing completion of color coats.

 

“Dirt” and “Age”

There were a few areas to which I wanted to add more color…and to rub some pigment into the grain, to emulate dirt. (I had already rubbed in some real dirt, but it wasn’t very convincing-looking.) Then, I locked it all down with a clear coat or two, and will polish it to completion. But this is pretty much the final color:

Final color, with

Final color, with “dirt” and “age”.

 

Side, with final color.

Side, with final color.

 

Back, with final color,

Back, with final color, “dirt”, and “age.”

 

What’s Next?

The next thing will be to re-fit the fingerboard, dress the fingerboard, and begin set-up. I will continue to address “polish and finish” issues as I see them.

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5-string report #15: Varnishing

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Five String Progress Report #15: Varnishing

Mineral Ground

I did not take any photos of this process…it only consisted of rubbing a gypsum suspension into the wood, all over, then rubbing it off, as completely as possible. The goal was to fill the wood pores, so as to limit the penetration of varnish into the wood. Apparently the varnish tends to dampen vibrations, and deaden the violin sound just a little. I don’t know how much effect it really has, but I got the idea from Roger Hargrave, who said it made a difference in his work. If it is good enough for him, I am game to try it. My suspicion is that my ears are no longer good enough to hear the difference, due to a lifetime of work in heavy steel. But…I have had very good reviews on the few instruments on which I have used the ground, so…either it really helps, or I have just improved my building skills, lately.

Sealer

My sealer is pretty simple: it is raw pine pitch dissolved in a combination of pure spirits of gum turpentine and alcohol. It penetrates pretty deeply, but the alcohol and turpentine (in that order) evaporate rapidly, and leave the pine resin in the wood. I rub off as much as I can of whatever is on the surface, and let it dry in the sun. Sometimes I have hung it up to dry indoors, but it does make the house smell of turpentine. My wife has very little sense of smell, and I don’t mind the smell, but others might, so I try to limit that sort of thing.

front with sealer

Front with sealer

 

Edge with sealer

Edge with sealer: notice the contrast between front and side. I hope to correct that, somewhat, with varnish.

 

Back with sealer.

Back with sealer. Still somewhat dull, but just wait until the varnishing begins!

 

hanging up to dry inside

Hanging up to dry inside.

 

Back drying inside

Back drying inside: I decided it was warm enough outside, so I moved it to the yard, and propped it in an old lawn chair.

 

Sealer drying in the sun:

Sealer drying in the sun: it was interesting to see that, as the wood warmed up, the sealer began to ooze back out of the pores, making tiny dots all over.

 

Varnish

Once the violin was very warm, and quite dry to the touch, I rubbed it down with a paper towel, to remove any residue, then coated the back with a yellow varnish, and the belly with a brown varnish. I hope to even out the color somewhat and diminish the sharp contrast between the dark, curly Koa and the nearly white Sitka Spruce.

First coat of varnish on the front

First coat of varnish on the front: makes quite a difference, doesn’t it?

 

one coat of varnish

There’s the whole fiddle in the sun, with one coat of varnish.

 

And...the back!

And…the back! Look how the curly Koa is catching the fire from the sun.

 

Koa Flame

Pretty serious flame in this curly koa wood! You can see why it was tough to carve.

 

Anyway, that is about as far as I expect to go, today. I may get another coat or two of varnish on there, this evening, but it will not be an appreciable visual difference until it is done. I expect to use at least another six coats before calling it complete.

Thanks for looking.

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