Oil Varnish

[Norskie]

I found an old (maybe 17-1800s) recipe for an oil based varnish that I'll try:
A pint of linseed oil (I'll use boiled, it's what I've got)
A lump of violin rosin (!) the size of half a hen's egg
Half pint of turpentine

Dissolve the rosin in the oil by heating and stirring it. (doesn't say how hot, I'll use a double boiler and a lot of caution)
Add any colourants, allow the oil to cool, stir in the turpentine.
If not used immediately, store in a crockery jar. (I'll use brown glass.)

The violin rosin is what caught my eye. I have a few knife handles and a hickory cane or two to try this on. I want to see if it will cure w/o UV light.

 

[Swampman]

"A lump of violin rosin"

My wife throws away a lot of fiddle rosin. When it gets broken or worn down she tosses it. I may try this.

 

[Zonie]

I recall reading about the making of varnish and it seems to me the linseed oil has to be heated to a slow boil.
A double boiler may not heat the oil up enough.
Also, there is a great danger of fire when working with hot linseed oil so be especially careful.

I think logwood or Alkanet root was used to create the redish color seen on some of the old varnished things.

Of course, when the turpintine is added to the mixture you've got a real potential for a bon fire so be extra careful.

Let us know how things work out.

 

[hollandbriscoe]

Just a little FYI, I know nothing about varnish but I do know that a hens egg at the time this recipe was written is not the size of a hens egg now. The eggs back then would have been about half the size of eggs today. So think small when adding your rosin. :thumbsup:

 

[Stophel]

To make a "real" boiled linseed oil varnish:

First, get yourself one of those deep fryer things. Get the hottest one you can find. Sealed element...little or no fire hazard. Oil fires are NOT fun...believe me! :winking:

Do this outside away from EVERYTHING with fire extinguisher handy.

Take 1 pint of store bought "boiled" linseed oil (which it isn't). Bring it to a slow rolling boil. If desired, add a teaspoon or less of lead carbonate ("lead white"..an effective period drier). The boiling will turn the oil a deep chestnut color and the smell will definitely change.

Prepare some resins in a glass container. Get about 6 oz. of resins. Rosin and mastic work well. I haven't used Sandarac yet. The last I did, I used 4 oz. of rosin, and 2 oz. of mastic. Put it in the glass container with about a cup or so of turpentine and let it sit while the oil boils.

Allow the oil to boil for a couple of hours (that's right), then add your softened resins and turpentine. Let it boil a good while longer.

When satisfied, turn off the heat and let it all sit and cool. While the concoction is still warm (but NOT hot!!!) pour it into glass jars (too hot and the jars will break..trust me!) You now have linseed oil varnish.

I have many thanks to both Eric Kettenburg and "Gray wolf" who have helped me arrive at this recipe.

For my next varnish project, I am going to use raw linseed oil with no additives and not put in any lead carbonate. I want to see how quickly it dries without it.

This varnish can be used as an oil finish easily, but with the added weather resistance afforded by the resins.

Also, you MUST have good sunlight for this to dry. It needs to be put on thin and put in fairly warm (say, above 45 degrees) sunlight. Under good conditions, it can dry in just a few hours. No sunlight, and it will NEVER dry.

 

[Norskie]

Update; I've got the rosin dissolved in the oil. The double boiler wouldn't let the linseed come to a boil, but the rosin started to dissolve anyway. There was a little bit left when I knocked off, but it was gone when I checked this morning. As for quantity, I just used the old cracked block that was in my fiddle case. Maybe an ounce. I'll try it tonight on some scrap wood.

 

[clayfeld]

Great article on oil varnishes at:[url] http://www.woodworking.com/wwtimes_oilvarnish.cfm[/url]

Clay
San Jose

 

[mbritt]

I'm curious to know is this type of varnish better? or just different? than other linseed oil type stock finishes. I was thinking about using a linseed oil & beeswax finish on my gun.

 

[Norskie]

This is what we're trying to find out. I believe ths is a musical instrument varnish. I want to find out how durable it is, how waterproof, how long it takes to dry. A combination of linseed oil and beeswax would also be an oil varnish. In fact in my recent research, I've found that the word 'varnish' was originally a verb, not a noun. So you would varnish something with wax, or oil, or whatever.
If it beads up water, I'll be happy.

 

[LSU TIGER]

A gunsmith from Colonial Williamsburg told me about a finish that's accurate and easy. Mix beeswax and turpintine to the consistancy of Vaseline and add a few drops of linseed oil. Warm the stock and rub it in. It will have a soft shine and be weather proof.

 

[Swampman]

Having used bee's wax and linseed oil mixtures for several different things, I will tell you they don't dry.

 

[mbritt]

What got me interested in linseed oil & beeswax varnish is that the Purdey website says they use it on their guns.[url] http://www.purdey.com/gb_finishing.php[/url]
Maybe they use some kind of special driers?

 

[Norskie]

Update: first coat on a hickory walking stick last night. I brushed on a thin coat and rubbed it in. This morning it's dry to the touch. I've thinned the varnish about half with turps, so it may have just sunk into the wood, but water beads on the surface! I'll work on this over the weekend and post again Monday.

 

[spitfire]

Another way to look at drying the finish is the Oil is hardening.The rate of drying is dependent upon humidity and temperature.Modern manufactures use a rotisserie arrangement with air blowers and infared heat lamps.I have used a hand hair dryer between coat and sanding.A fast way of putting four coats on a stock(4 hours max).Usually in as little as three hours for harden cure.The trick is not to over heat the stock(the finish will bubble if overheated-I have a toothpick available to pop and blow flat the bubble just in case)by manually rotating the stock and hair drier.With a little practice you can gage speed and distance to hold.Multiple bubbles or foaming means too hot!!This can result in long hours of sanding out the flaws! :winking:

 

[Swampman]

Sunlight will cure most natural finishes faster than heat. I don't like heat much because it pushes the finish back out of the wood, in my experience.

 

[kettenburg]

This is a classic 'common brown' or 'cheap brown' varnish. The resin loosely termed as 'rosin' by stringed instrument players is a rather crudely refined generic conifer resin extracted from various species of pine. It will add a gloss to the oil and not much more - it is a very brittle and porous resin that does not add much in he way of weather protection. However, it is rich in the terpenes also present in turpentine (turpentine basically being a much more higly refined by-product of this same resin extraction) which serve to absorb oxygen and introduce it into the oil: his will aid drying, but UV light is still the name of the game. For added drying benefit, heat the turpentine in a double boiler and bring it to a low bubble (it can flare and ignite if you heat it too quickly, so make sure you have something near at hand to cover the container thus cutting off the flames oxygen supply) and maintain it at this for a few days. Obviously you will have to turn off the heat while you sleep! But if you can reduce the turp to a honey-like appearance and consistency it will carry much more oxygen into the oil and will also be much more akin to what 18th century varnishmakers referred to as turpentine. Rock on!

 

[Stophel]

Does mastic or sandarac make a better varnish than rosin? I have been putting some mastic in with the rosin. I don't have any "long term results" yet, so don't know how one might fare over the other. I've seen a lot of old varnish recipes calling for sandarac.

 

[Norskie]

Another update.
This stuff does seal wood. I tested scraps of maple, hickory and walnut. I applied it with a brush and then rubbed it in by hand as though working with straight linseed oil. After letting the first coat dry overnight, the second coat did not absorb as well. I think the rosin has sealed the pores in the wood. I'll see if my test pieces will take any more coats. The hickory walking stick now has three coats, but the last one wasn't drying after a day (cloudy weather, very little UV), so I applied some carnauba floor wax, which seems to have dried the finish. I have no idea why. I wouldn't call this stuff varnish, as we understand it, but it's looking like a pretty good sealer. I'm going to try it on some real open pored wood like pine.

 

[Norskie]

Last update on this oil varnish. I guess it's a varnish. It seems to take about 3 coats rubbed in. The third coat builds on the surface and takes a definite polish after hand rubbing. It doesn't leave a thick coat, it looks like an oil finish, a little glossier than the 'London Dull' finish that took me so long to achieve on my first deer rifle. I'll do some durability tests next, a year's worth on my walking stick. Then I'll try it on a gun I'm building.
Moose