Peter KG's Bench

[Peter K-G]

Purity of linseed oil?

 

I left the different qualities of linseed oil out to see how they would polymerize.

 

Salad quality from supermarket, Finish cold pressed, Kremer refined

 

 

Not a single fly in the salad linseed oil!

Some small flyes in Finish cold pressed and a lot of flyes in Kremer refined linseed oil.

 

This is probably a coincident, but interesting!

 

Another interesting thing is that the yellowness in the Finish quality has allmost disappeared.

[Patrick KREIT]

C'est génial !!!

[Peter K-G]

There is a festival in our hometown and people are having garage sales at the market-place. So my wife and I stumbled over a crappy old violin that someone had inherited from a relative a long time ago. I looked at the violin for a while and walked ahead. My wife obviously saw that I had some interest in the violin so she went back and bought it for me

 

So now I have something to practice varnishing on, plus a lot of work and I'm supposed to be on summer vacation!

 

First I thought it was an amateur home made violin, but it's a really bad made factory violin with bassbar from the same piece of wood. Both top and back wood is good, straight cut and very thick. The top wood is really dark straight through. It's "crispy" and seems to be at least a 100 years old. Everything is glued with something that is as strong as epoxy. I had to bring in the BIG knife

 

A0 = 291/284

B0 = 262

A1 = 478

B1- = 524

B1+ = 578

 

After opened the top was 89 g M2=197 and M5=402, planed down the "bass bar" and thinned down to 2,5 - 3,5 mm 70 g, M2=142 and M5=317.

 

[Peter K-G]

After some lazy days I forced myself to continue with this ugly project. Striped of the varnish of the back, evened up and cleaned the inside. And thinned the ribs to ~1.3 mm. The varnish is hard and thick - maybe it's shellac, I don't have experience with that.

 

I don't know what the dirt is either, but it looks like soot, I also found it on the top under the fingerbord, strange

 

A lot of work!!!

 

The coupling frequency is 285 Hz (the other one 348 Hz), humidity is 60%, 235 g

 

 

[christian bayon]

There is a rule in restoration , NEVER remove the varnish! even if you don't like it!

[Peter K-G]

There is a rule in restoration , NEVER remove the varnish! even if you don't like it!

 

 

Oops

 

(The violin cost 100 €, with the ugly case and the terrible bow)

[christian bayon]

Doesn't mater , in the XIXth century the Testore violins was considered crap!

[Peter K-G]

I striped a chinese 2011, is that allowed

(It was so ugly that I sprayed som furniture varnish on it)

 

It was a tuning/sound experiment. It is now a nice mellow sounding folk music fiddle.

 

 

  

[Peter K-G]

Back to my ongoing project. This is the second time that I'm working with old wood. (over 50 years at least) It is not the same as my processed, heat treated.

It smells old, the dust does not fly around. When varnish is now striped off the top also, the spectra when tapping is kind of cleaner.

 

M2 dropped 5 Hz and M5 dropped 2 Hz

 

(What if it sounds better than my #5  )

[Patrick KREIT]

Peter,

If you tune the back plate and the re-barred top plate according to the method with which you are familiar, taking the moisture content of the wood into consideration, this violin should be as good as (but not better than) your Violin N° 5.

 

Don't forget to glue the fingerboard on temporarily and set up the violin in the white, for it may require a final positive adjustment of the  B1- and B1+ frequencies.

 

www.kreitpatrick.com

[Peter K-G]

Purity of linseed oil?

 

I left the different qualities of linseed oil out to see how they would polymerize.

 

Salad quality from supermarket, Finish cold pressed, Kremer refined

 

FlyesInLinseedOil.jpg

 

Not a single fly in the salad linseed oil!

Some small flyes in Finish cold pressed and a lot of flyes in Kremer refined linseed oil.

 

This is probably a coincident, but interesting!

 

Another interesting thing is that the yellowness in the Finish quality has allmost disappeared.

After a couple of weeks all yellowness has disappeared from all of the samples. Finish cold pressed and Salad linseed oil has polymerized. Kremer refined has NOT! Now I don't know which one to use for my varnish cooking next week. And should I take the yellowness away before cooking?

[Patrick KREIT]

Cold-pressed linseed oil. If you have some time to spare, expose the oil to sunlight. The color does not have direct significance for the varnish.

 

www.kreitpatrick.com

[Peter K-G]

I figured out why the violin looked so dirty.  It's not dirt, it's grayed wood, didn't come to think of that, not too obvious for a violin. This violin has been treated really bad and stored outside, probably in a cold shed or something. The wood is not week yet but it's really dark in some places.

 

I'm making progress with tuning and starting to get a good feel for it. If I would do Violin #5 top again I could probably bring the weight down a little.

 

Not world class restoration but it's a start:

 

 

The bass bar is of old high dens Finish spruce timber. I had to patch the bass side under the f-hole. there was a crack and it was only ~1 mm thick. the other crack is glued and goes right under the bass bar. I made the graduation as even as it was possible.

 

MC% = ~8 - 9

weight = 68 g

M2 = 150

M5 =  338

 

Bass bar ~3,5 g, 10,4 mm (it's almost straight looking from the side)

Back coupling frequency has decreased to 281 Hz

 

Tomorrow I will size the inside with casein+lime, mixed with 5% linseed oil

[Michael_Molnar]

The secret to stability of the back and top plates is the effect of creep on materials in the white: they must be dehydrated, rehydrated, dehydrated, rehydrated, until the wood can no longer regain a high moisture content and until the frequency of the materials cannot rise above its maximum. If you are too impatient to do it yourself, then you will have to wait for years while Mother Nature does it for you!

 

...

I have long suspected that this humidity cycling is important. My evidence is anecdotal so far. Nevertheless,  I moved most of my wood into the garage and attic where Mother Nature can do her magic - maybe. I keep in my shop only enough wood for jobs in the next 6 months.  I wonder if anyone else has observed this cycling effect. It would be interesting to cycle some tonewood in a closed chamber. Anyone try that?

[Don Noon]

I It would be interesting to cycle some tonewood in a closed chamber. Anyone try that?

Sortof.  But only a few pieces of wood, 2 cycles to ridiculous extremes, so it's not really a good indicator of what ambient cycling might do.

[Patrick KREIT]

Michael,

Creep does not function as well on raw materials for it requires more time, even several years; whereas on finished top and back plates in the white, the results are very rapid (15 to 20 days).

 

www.kreitpatrick.com

[Peter K-G]

Frequencies are back to as they where before sizing inside. (coupling frequency back/rib 281 Hz, top 338 Hz)

 

This is suprisingly simple, easy and super nice!

 

10 g Kvarq (Casein)

2 g Lime paste (slaked lime)

~0,5 - 1 g cold pressed linseed oil

 

=> mix and apply with a cloth (two times), I polished the surface afterward with a linen cloth.

It still smells like visiting a fishing harbour at summer   (ammonia)

 

The surfaces are slighty more yellower/greenish and a little shinier, otherwise you wouldn't notice.

 

[Patrick KREIT]

In a little while, this yellow-green color will disappear and the casein will be invisible. Casein made with borax is invisible from the outset.

 

www.kreitpatrick.com

[Peter K-G]

It is going to be a DG sounding violin

First snapshot after gluing yesterday evening, temporary FB, soundpost and without CR:

A0 = 279

A1 = 472

B1- = 436

B1+ = 537

The frequencies will rise a little after glue has dried properly.Total weight without FB 309 g. The neck is small and light, back and ribs are likely to be ~10 g heavier than #5.

[Patrick KREIT]

These frequencies are appropriate. If this violin sounds as good as I expect, it proves that: a) the method works for both new and old instruments and the luthiers that reworked the thicknesses on certain violins knew what they were doing. Jonathan of platetuning.org has also been very successful at this. If the G string is a bit dry, reduce the opening of the f-holes as indicated in the book.

 

www.kreitpatrick.com

[Peter K-G]

I'm now a varnish cooking expert

 

So who is the first to put this stuff on a brand new violin?

I call it Abba secret formula violin varnish:

 

 

 

 

 

 

 

 

 

 

[Michael_Molnar]

Peter, How about displaying together the before and after treatment measurements for a discussion?

 

Patrick, I agree that green wood would not cycle due to trapped viscous resins and liquids, but (I think) what I do store would cycle.

[Patrick KREIT]

Michael,

 

Moving your wood to the garage or attic creates a humidity cycle. If you do not control the humidity in your workshop, you will likewise obtain a cycle of creep in the wood that will be considerable from season to season, between the different levels of temperature and moisture. In my workshop, the moisture content of unworked wood can change from 0% to 10% over the course of 4 days in winter (with the heating on). In summer, the wood can also dehydrate to 0% (as it is right now) and regain up to 10% MC, but over a longer period of time. This is the advantage of wood that has dried between 5 and 7 years: once such wood has been transformed into finished violin plates, the creep cycle leading to stability of the materials (i.e. stability in their frequencies) is more rapid. 

 

www.kreitpatrick.com

[Peter K-G]

Peter, How about displaying together the before and after treatment measurements for a discussion?

 

The casein+lime glue size treatment did not change the frequencies.

 

I decided to decrease B1+ 5 Hz before I filled the pores with colloidal silica and sizing with casein+lime. Didn't manage to drench all the colloidal cilica with the size, so there is som white spots left. A better way whould probalby have been to add the powder directly into the size. => practice is good

 

 

 

 

[Peter K-G]

A little warning!

I have a fingerprint reader on my laptop to log on, the size takes away your fingerprint if you are stupid and don't use gloves

Had to enter the password to log on. It will be okay, my fingers are fine but next time GLOVES!