Fulton's book on violin varnish is still available

[Mike_Danielson]

I wanted a copy of William Fulton's book "Turpentine Violin Varnish", but could only find one rather expensive used copy. I decided to directly contact Mr. Fulton and through the help of VSA finally got a working email address. He has copies for sale. Cost is $37.00 (USD) + $5.00 shipping (This is the shipping he charged me, it may differ if you are outside the U.S.)

wfulton1@verizon.net

W. Fulton

PO Box 254

Idyllwild, CA 92549

I have tried this varnish, recently. By overcooking it, I was able to achieve a nice red-brown varnish which was easy to apply and dried fairly quickly (4 days in the light box if I added 10 drops of japan drier to about 7 ml of varnish). It only took 4 coats to give me the desired color. The varnish is very soft.

Converting the oxidized turpentine to the varnish must be done with great care (outside, away from anything combustible) because this stuff can rapidly start on fire. As you initially heat it up, the decomposition of peroxides followed by polymerization generates so much heat that unless you quench the self-generated heat, it will burst into flame. Don't do more than 500 ml at a time and put the metal pot into a container of water until the internal boiling stops; then reheat. You quench when the internal boiling starts getting vigorous and seems to be taking off all on its own when removed from the heat. Do this over and over again until the process settles down to a slow boil. Then you can bring it up to temperature. I stop cooking when it gets to the right color. You can go all the way from light yellow to amber to red-brown simply by controlling the cooking time (or more likely temperature). The red-brown varnish was rock solid when cooled down. I reheated it over a water bath to make it liquid and added cold-pressed flaxseed oil to get a liquid varnish. You must use turpentine as the solvent rather than mineral spirits for complete dissolution. You have to add a drier if you want it to set up in a reasonable time.

[Andres Sender]

Al Carruth mentioned somewhere that there's a way to prepare the turps which cuts down on the production of peroxides, so that 'running' the resin is safer. I'll try to dig up the info.

[Jacob]

When you mentioned the mineral turpentine, did you mean that one should not use it as a thinner when preparing the varnish, or not for futher thinning later on? I use it for subsequent thinning with no problem, but I use gum turpentine in the preparation.

I'm also puzzled by your comment that the varnish needs a drier. In my experience a coat is try to the touch within a few hours of exposure to the sun. I don't know how well it dries in a light box.

[Jacob]

Andres, I think it has to do with the addition of zink oxide. One can also prevent commbustion by initially heating in a water bath, or simply leaving the stuff open for a few months to let the stuff which causes the exothermic reaction to evaporate.

[Andres Sender]

My very fallible memory says he gently heated the stuff while it was being bubbled, but don't quote me.

I wonder if the drying issue has to do with differences in quality or preparation of the oil.

[Mike_Danielson]

I don't think there is any way to avoid the peroxide formation--they are necessary for varnish formation. The peroxides decompose with heat, leading to polymerization, thickening, maybe the formation of the color centers, and maybe the formation of additional unsaturation so that the varnish will dry. This varnish making process has not been scientifically studied to my knowledge so this is speculation.

Fulton is clear that you must use gum spirits of turpentine that are derived from the pine tree to make the varnish (gum spirits, fortunately, come from the pine tree). I use gum spirits as a solvent to thin the varnish because you get total solubility of the varnish. The varnish will not completely dissolve in mineral spirits.

My first coat of varnish had about 5 drops of japan drier to about 7 ml of varnish and the coat was still wet after 24 hours in my light box--it took a weeek for it to dry. Next time, I used 15 drops and it was dry in two days.

The old varnish makers have been reported to use lead oxide as the drier and would boil the varnish in its presence; so driers appear to have a long history.

Now I have a question for you readers--are there many luthiers using the Fulton varnish? Does anyone use the yellow propolis soap for the ground? Do you think the varnish looks authentic like the Italian masters used?

[Jacob]

In the supplement which comes with the book itself, Fulton says that the thinning can be done with mineral turpentine.

Anyhow, for the thinning at the end of the cooking process with the resin and oil I use gum spirits. After that, for further thinning prior to use, I use mineral turpentine. If one uses gum spirits for this, it has to be very fresh - even a small amount of oxidation seriously retards drying.

I don't have a light box, and as I've said, a coat is dry to the touch within a few hours of exposure to the sun. After a day, certainly a coat is dry enough to rub down, so I've never even considered using driers.

I used the propolis soap for a while, but since I couldn't discern any aesthetic or tonal advantages, I stopped using it.

This is my varnish of choice, but whether it looks like the varnish on Italian classical instruments I can't tell, as I've seen so few (two Carcassis and a lesser Grancino).

[Seth_Leigh]

Mike, I bought some propolis a week or so before I left on the two-week trip I'm still on right now. I have some soaking in alcohol right now. Michael recommends I just take what dissolved in the alcohol and not use what didn't, which is quite a bit. I don't recall Fulton saying to expect so much not to dissolve so I'm curious. I only had soaked it in alcohol for a few days before my trip; when I get back on Tuesday it's entirely possible it will be more dissolved. I'll just have to see.

Jacob told me he stopped bothering with the propolis soap too, but I'm curious and want to see it for myself, plus I'd already bought the propolis.

I'll comment on it when I have it done and tried it out on some scrap wood.

[jmasters]

Peroxides will form in the "bubbling" or oxidation process..... I think that several years ago on another forum I was the first to mention zinc oxide. Of course, lime would work too....... about a teaspoon per 300 cc of oxidized material. As soon as the melt starts to emit bubbles, remove and stir. You will see the oxide being taken up. If you wish, add until there is an excess. This will simply filter out at the end of the process.

The Zinc compound resulting will take alizarin to quite a degree to make brilliant red. This may fade somewhat, but is certainly more red than the iron compound. If you like aluminum lakes, that is too bad, because aluminum oxide will not disolve in anything.

However, the peroxides react with the oxides and there is almost no evervescence or danger in the cooking.

My only complaint about the Fulton varnish is that it dries very slowly and very soft. I have also used various driers. Cobalt dryer from the art store is OK, but it is a "top-down" dryer. Japan dryer contains manganese, zirconium, and perhaps calcium. Perhaps traces of others. If you want the raw oxides of these materials, good luck. Or perhaps some other salt of these. If the ancients used them, perhaps you can find a metal-content analysis of the old varnishes somewhere. I have seen it, but cannot say where. In any case, lead predominates, as it should. The EPA does not like lead, but to hell with them.

Here is a hint.......... and the best one I have discovered. Any metal oxide seems to work (besides aluminum) so you should try lead oxide (litharge.) This makes a much better drying resin. Lead is THE drier par-excellance. But I do not know the color with a complex of Alizarin.

The Fulton resin is produced commercially by the Hercules Poweder Co. I once bought an 85 lb bag for experiments. It was cheap at less than $2 per Lb. Hercules has been bought out, but you can find them somewhere on the web.

The resin, poly-beta-terpene has a very low melting point. Or rather, softening point. (It is not a true solid, but a rather viscous liquid; or you could say an ammourphous solid.) Its main commercial use is in chewing gum. Reminds one of Mastic ???

The hardness and toughness of the film will depend on the oils used. Cold-pressed oil may or may not be good. You may try a partially-polimerized oil such as stand oil or many other things. But a short oil-varnish can only be hardened a certain extent. The ultimate determinant is the nature of the resin.

[Jacob]

I've used purified artist's linseed oil, and also stand oil.

I'm intrigued by the reports of this varnish drying slowly - what is considered "slow"? Is a day in the sun for a single coat "slow"? I've never used driers.

The varnish does takes several weeks to set so that a bridge will not leave an imprint. However, after a few weeks it won't take imprints from cases, fingers, etc, as one hears some varnishes do, even in hot weather.

[jmasters]

Perhaps my coats were thicker. If your dryer was "top-down" then a thinner coat would be quite an advantage. I will admit that old samples of mine seem quite firm and of a good hardness.

Do you have any comments on the other points ??

[Jacob]

The only comments I may have concern my observations and experience in using the varnish. I've tried zink oxide and alarazin once, with somewhat unsatisfactory results. Nowadays I add coloring matter to the varnish.

I've never had the need to use driers. After the varnish has been made, I still thin it some more before application, sometimes with fresh gum turpentine and stand oil, sometimes with mineral turpentine. I end up using about 5 thin coats. In this climate, I can set up the violin within three weeks of having started varnishing. If one can live with an imprint from the bridge feet, within two weeks. Whatever the resin might technically be, once the varnish has set, it becomes hard and solid enough quickly enough so that I can describe it as a "practical" varnish - easy to apply, durable without being a "coat of armour", and above all, it looks good.

[Mike_Danielson]

I received the books from Mr Fulton, yesterday. They consist of a hard back edition of "Turpentine Violin Varnish" and a spiral bound book, "Violin Varnish: Formulation Manual."

The manual appears to be very useful. It contains 15 different formulations starting with how to make a heat-bodied linseed oil, there are formulations for making cobalt and lead driers, a concise method for making the turpentine varnish, and it finishes up with a recipe for making a varnish emulsion using the turpentine varnish. There are also test metods for viscosity, nonvolatile content and drying time.

I am pleased.

[Jacob]

I think you will experience that slight variations in the preparation can yield varying results - just like a culinary recipe. I don't bother too much to avoid the exothermic reaction, I only want it not to catch fire. By now I know when that is, so at a cetain stage I just leave the oxidised turpentine off the heat and let it build up by itself until it starts boiling and smoking with orange foam rising in the bowl. This violent and rather sudden process takes about 30 seconds - in that time the temperature goes up from about 120 degrees to over 200 degrees Celsius without a direct source of heat. When this witches' cauldron subsides, the yellow liquid has turned a bright, deep red. I then boil it for a few minutes at about 250 degrees, and then let it cool. It hardens in the bowl, and I just whack it out with a hammer. These chunks of resin I boil at about 300 degrees with stand oil or purified linseed oil till it forms the magical "firm pill". I don't worry too much about the ratio of oil to resin either, but one should have more resin than oil to prevent crackling of the varnish. I dilute when it has cooled down to about 120 degrees with the appropriate amount of FRESH gum turpentine.

Prior to use, these days I thin with mineral turpentine (I've also use a mix of linseed oil and FRESH gum turpentine) and strain through a nylon stocking. This is very easy to apply, dries within a few hours, and is zits-free.

Thinning at the preparation stage, but even worse, afterwards, with even slightly oxidised gum turpentine (a half-empty bottle older than a few weeks is enough to cause this) will render the varnish tacky and slow-drying.

The resin is very soft (low melting point, as J Masters mentioned) and would probably be useless in a spirit varnish. However, its bonding with a drying oil at a high temperature would seem to render it harder and tougher than the resin by itself. For me, this is THE VARNISH. I've tried out many commercial violin varnishes in my time - all with impeccable credentials - as well as verious DIY recipes (but not Michael Darnton's mastic varnish) and this one has the beating af all I've tried by a long shot.

I've mentioned before that I don't have a drying box and that I depend on direct sunlight at all times, but just in case you think I live in a violin varnisher's Xanadu, one of the Cape's tourist mottos is "All four seasons in a day". Before I apply a coat of varnish, I consult four different Internet weather sites, and apart from that I personally check on an hourly basis what's going on outside. Nevertheless, I avoid varnishing in winter, which is no big deal, as I can complete varnishing half a dozen violins inside two weeks in summer. So in winter I carve - besides, when it's that cold, you don't feel it when you cut yourself.