Is this product suitable as violin varnish?

[geerten]

Hi,

today I was in a traditional paint store in the old and beautiful

city of Delft (the Netherlands), looking for products for

varnishing. One of the shop assistants suggested varnish by the

brand Le Tonkinois classic line) as a possibility for violin

varnish. Normally this product is used for outdoor lumber,

furniture and boats. It dries in 24 hours and gives thick elastic

layers (according to the product sheet).

I searched for some internet information and this varnish is said

to be composed of some natural resin, and linseed and tung oil. To

me this sounds like some traditional violin varnish recipe! It

reminds me of the idea that the ancient violin makers probably used

general purpose products for their instruments.

Does anyone here has experience with this product?

"http://www.solventfreepaint.com/linseed_varnish.htm">http://www.solventfreepaint.com/linseed_varnish.htm

Thanks,

Geerten.

[Oded Kishony]

It may be suitable but I'd want to thin it so it doesn't form a thick coating.

~OK

[Michael Richwine]

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I'd like to know what resins are in it.  Linseed oil by itself
is a lousy finish, because even when fully cured, normal room
temperature is above its "glass transition point", so it stays
soft, and constantly collects dirt from the environment.  It
also turns black on its own, over the years, and its water
resistance is close to nil.  It also soaks into the wood,
which will kill any tone the instrument might have had.



That's why linseed oil is cooked with appropriate resins to make
varnish, which is harder, more durable, and water resistant,
and doesn't soak into the wood as much.  Variations in the
proportion of resin to oil, as well as choice of resins, determine
varnish characteristics.



Tung oil is another drying oil, but also soaks into the wood.
 Water resistance is good, but it doesn't build much of a
film. and I don't think you can polish it.  It's a good
additive for some purposes, but doesn't strike me as being very
useful on violins.



From the advertising, I'd guess that it's not a suitable finish for
an instrument.  Couldn't find an MSDS.



Fiddlecollector wrote in another thread:



"Nonado,the link in the other thread ,`Is this suitable for violin
varnish`,has authentic Swedish pine tar.(i assume this is the black
pitch your looking for?)

On reading their literature of supposedly 100 % natural linseed
oil,it sounds like they dont add anything to the boiled linseed
oil.But on reading the safety data sheet ,they clearly mention
manganese being added to the boiled oil."



Pine tar is liquid.  Pitch " text-decoration: underline;">appears to be a dry solid.
 Both are products of destructive distillation of wood, as in
charcoal making.  We tried cooking pine tar to make pitch.
 Got "das Pech" instead.



Boiled linseed oil used to mean oil that had literally been boiled
to jump-start its curing.  For the last hundred years or so,
it has meant (un-boiled) oil that has driers like manganese added
to make it cure faster.

[geerten]

Hi Oded and Nonado,

thanks for the quick replies! Nonado, two things you bring up, the

sort of resin and the siccatif, are two things i was wondering

about too. I already sent an email to the Dutch product manager of

Le Tonkinois before i posted this message here, asking him about

this. Have not yet received an answer yet.

Nonado, your remark about the 'glass transition point', do you mean

that a good varnish has to be in the glass phase at  room

temperature? Doesn't this mean that the varnish would be far too

hard and chippy? In my opinion, a good varnish should have a

glass-point below room temperature, and thus be in the rubber

phase, for good elastic properties....

After some more searching, i found a discussion on a guitar making

forum, about the use of this particular product as a guitar finish.

Some people there have quite good experiences with it. The varnish

is said to give a high gloss and can easily to be

polished/sanded:

http://projectguitar.ibforums.com/index.php?showtopic=23903

One of the reasons i've posted this topic is to hear people's point

about using a varnish that is not typical an instrument varnish.

Why would a general purpose varnish made from natural ingredients

(like the one i mentioned) be inferior to a commercial available

violin varnish? Are modern makers too picky in their choice of

varnish, inspired by the myth surrounding the magical varnish

of the Cremonese masters? Posts your views please...

Geerten

[Japes]

I think this is the same stuff Kremer sells, and they do indicate it as a suitable violin varnish.

http://kremer-pigmente.de/shop...product=79055〈=ENG

[mignal]

null

Scroll down to the FAQ on Asthma, it states that it contains 'natural resins'. Seemingly dries very fast but I don't now how they achieve that without adding driers of some description. I'd like to know what the 'natural resins are.

[rb_quebec]

http://www.letonkinois.net/index.php

Here's the internet site of the company that makes the varnish.

 The english pages are not working.  You have to try

another language.

It's surely not the same product in the kremer catalog because

there is natural resins in Le Tonkinois and not in the tung oil of

kremer.

Bye

[DutchViolins]

Do I understand it right that the colour should come from the substrate itself? Wouldn't this made a staining procedure necessary before treating the wood (violin) with this material?

Can oil soluble dyes be added to reach the desired coulour?

IMHO a rubbery state of the film will demonstrate a significant dempening factor. This can be reduced considerably by using a siccative (Cobalt-complex) to allow cross linking and polymerization of both Tung oil and linseed oil.

[Japes]

Is 'Le Tonkinois' Dutch for Tung Oil Varnish?

http://kremer-pigmente.de/shop...lang=NLD&product=79055

[DutchViolins]

No, although there are some sounds in the word that make people think they hear something like Tung The word is pure French and has nothing to do with Dutch.

[Japes]

That's right, so this seems to confirm that the Kremer tung oil varnish is, indeed, Le Tonkinois, which actually means 'The Tonkinese'. I'm guessing tung oil's origin is Tonkin?

[Oded Kishony]

> Why would a general purpose varnish made from natural ingredients (like the one i mentioned) be inferior to a commercial available violin varnish?<

It isn't necessarily inferior it's just that it hasn't been proven to work particularly well on a violin.

>Are modern makers to picky in their choice of varnish, inspired by the myth surrounding the magical varnish of the Cremonese masters?<

That's probably true but the varnish on an instrment has to meet many expectations, clarity, depth, color, density, damping properties, abrasion resistance, ability to polish out well, ability to French polish, resistance (or non resistance) to various cleaning solvents,glossiness, resistance to the effects of rosin's acidity, resistance to body chemistry, ability to gracefully age and of course the acoustical properties of the varnish. Commercial varnishes do some of these things well but not others. It's very hard to find a single varnish that does everything really well or that's been documented to do all these things well. Most violinmakers, having spent considerable time and effort in building their instrument don't want to risk ruining it with an inferior or unproven finish.

Oded

[Michael Richwine]

quote:

---

Originally posted by:

geerten

H. Nonado, your

remark about the 'glass transition point', do you mean that a good

varnish has to be in the glass phase at  room temperature?

Doesn't this mean that the varnish would be far too hard and

chippy?

---

The proportion of oil to resin, and the choice of resins will

determine how hard a varnish will get, as well as its toughness

(resistance to chipping.)  Glass transition point (Tg)

indicates the point where a polymer goes from rubbery to hard, but

not necessarily brittle.  It can have various degrees of

hardness and toughness.  If it's not hard, you can't rub it

out or polish it, and I imagine it has a damping effect on sound.

[geerten]

Hi Nonado,

I did some more thinking about the 'rubber-glass transition', with

respect to varnishes. For normal commodity polymers (like

plastics), the glass-point is mainly defined by the flexibility of

the polymer chains. Thermoplasts have chains that are not

interconnected, and at a certain temperature, these chains get

enough thermal energy for movement other than vibration (rotation,

translation). Polyethylene is at room temperature in the rubber

phase, while polycarbonate or PVC (without softeners)  are in

the glass phase. Has to do with the side groups and main chain

geometry.

Point here is that the chains have to be free of cross links (or

maybe only crosslinked to a minor degree) to be able to move freely

and go into the rubber phase. For a cured varnish, that's maybe

more like a fully crosslinked network structure, as in a vulcanized

rubber or thermoset. I'm not sure whether or not the glass

transition point is still as sharply defined as for material with

unconnected chains.The glass transition temperature will shift up

higher, which means that a cured varnish will likely be in a

glass-like phase, unable to come into a rubber-phase at all.

Increasing temperature would possibly only lead to

decomposition.

What's your thought?

Geerten.

[Michael Richwine]

It gets fuzzier with varnishes than with plastics, that's for sure,

but I think you've got the idea (much more complex reactions going

on).  Some varnishes won't harden below a certain temperature.

 Catalyzed finishes can be particularly sensitive about this.

 Also, many violin varnishes require the additional energy of

UV light in order to cure out within a reasonable time. However

once cured, finishes that cure by oxidation and/or crosslinking are

generally not reversible.  Heating them past a certain

pont just results in degradation of the film, just as excessive

exposure to UV light does.

[Johnmasters]

quote:

---

Originally posted by:

geerten

Nonado, your remark about the 'glass transition point', do you mean

that a good varnish has to be in the glass phase at  room

temperature? Doesn't this mean that the varnish would be far too

hard and chippy? In my opinion, a good varnish should have a

glass-point below room temperature, and thus be in the rubber

phase, for good elastic properties....

---

Glass is very elastic. The damping is very small, it rings well when struck. Rubber has lousy elastic properties.