lead carbonate

[billd]

When boiling linseed oil people have posted adding about a teaspoon.  Any idea what this would be in ounces of weight?  This stuff in expensive and sold by the ounce. 

Thanks,
Bill

[rick landes]

2 tablespoons make an ounce and 3 teaspoons make a tablespoon...

[Joe S]

Lead carbonate is 32.5 grams / teaspoon.  You can buy 500 grams for $22.56 at http://www.sciencestuff.com/prod/Chem-Rgnts/C1974.  If you are using 1 teaspoon of lead carbonate per liter of oil, you could make 15.4 liters of varnish from 500 grams of lead carbonate.  15.4 liters is 4.1 gallons.  That should be enough to do a couple of guns, I would think.

[billd]

Joe , 

Thanks for the reply. What is the difference between the link you gave me and this one?   http://www.sciencestuff.com/prod/Chem-Rgnts/C1973    It's much more expensive, that's what I was refering to in my post.  One is basic, the other isn't, whatever that means.

Rick,  you talking about liquid measurements. I meant solids.  If you took a teaspoonful of lead carbonate and weighed it on a scale, about what would it be?

Thanks for all the help,
Bill

[Joe S]

Your link is to pure reagent grade lead carbonate (PbCO3).  The link I posted is for lead carbonate that is 2/3 lead carbonate and 1/3lead hydroxide (PbCO3)2·Pb(OH)2.  The word basic refers to the OH group. 

The cheap stuff is what you want for varnish.  This is what they use for white pigmnent too.

[J. Talbert]

Rick,

Your teaspoon & tablespoon equivalents are correct as stated, however they refer to a liquid ounce, or nominally 30ml.  In this case the weight per volume as stated in Joe's reply is the the pertinent bit of info, and varies from compound to compound.

Jeff

[Dennis Glazener]

Bill,
I will stick my nose in here to tell you what I did on an old time linseed oil/turpentine mix that Earl Lanning gave me. The mix had me adding several corroded lead bullets to the mix to add lead carbonate. Not having enough corroded lead I substituted a few drops of Japan Dryer and it worked well as a substitute. Gave some to a friend of mine and he told me (about a year later) that that stinking finish that I gave him worked wonderfully and wanted the recipe!
Just FYI,
Dennis

[billd]

Thanks Dennis,   
What I want the lead for is it turns the oil a dark redish brown color, at least that's what I read.  I want to try this on a cherry fowler I'm building. I want to darken the wood somewhat but not as red that lye gives.  Plain linseed oil will darken it but I'm looking for a little bit more.

This is my first time trying this. I picked up a deep fryer at a Goodwill Store, so when the weather breaks I'm ready to stink up the neighborhood. I may try EK's method of round balls and vinager instead of buying it.

Bill

[Sean]

Chuck Burrows suggested using this:

https://store.studioproducts.com/Liquid-Lead-Drier-lead-napthanate-24-p-16153.html

Maybe he'll come on here and add his experience.

Sean

[Mad Monk]

Don't get too tied up in exactly how much lead to add.

Most of the old formulas run to an excess of lead in the finished oil.  

If the oil is boiled (cooked) properly it will at first be a redish brown color.  During the cooking you create a lot of "gel" particles in the oil.  You also get all kinds of solid particulate cooking reaction debris.

After cooking I would filter my oil through several layers of tightly woven cotton muslin after it had cooked a bit.
Then transfered, when cool, into jars.  Pieces of cotton muslin covering the tops of the jars to keep out dirt but not oxygen from the air.  When they produced boiled oil in a factory they would "tank" it to let the worst of the cooking reaction debris settle out.

With lead as the dryer metal the oil does not form a hard skin on the surface while "tanking" in the jars.  Lead is a through dryer meaning the oxygen picked up is transfered down through the oil.  It will dry uniformly from the top of the liquid to the bottom.  In the process the oil is clarified and its viscosity will increase.  In German paint factories they felt that 3 years of "tanking" was good and anything less was an inferior oil.

A properly boiled and age "clarified" oil will be deep ruby red in color.  But that red color does not show up on the wood because you are using it in very thin films.  It gives a slight orange tint at times.

This thickening or gelling of the oil during the "tanking" step is part of what hand rubbed finishes were all about.  You really have to work it on the surface of the wood.  During this rubbing you are working some atmospheric oxygen into the oil film on the wood.

When the oil gets almost Jello-like in the jar you can thin it with aged turpentine.  Simply pour a little turpentine into a bottle and cover it with a cloth.  The turpentine picks up oxygen from the air.  Two molecules of boiled oil will share one atom of oxygen.  When added to the boiled oil just before applying it on the wood you are adding oxygen right into the oil.  The oil does not have to pick as much oxygen out of the air in contact with the surface of the oil film being applied.

This trick with aging turpentine so that it picks up oxygen from the air is why you sometimes see old writings where turpentine is listed as a dryer rather than as a thinner or diluent.

In the case of Venice turpentine the turpentine also includes some of the resin from the European Larch from which it was obtained.  This in effect makes it a varnish.

E. Ogre

[LynnC]

MM  or DP or both or others knowledgeable - would you please describe your method of "cooking" your BLO?  Does it require the rolling boil of the deep fat fryer or is the slow cooking of the second hand crock pot sufficient?

How long is turpentine "aged"?  Just some things I need to learn.
Thanks........................Lynn

[LynnC]

BTW - I slow cooked (about a week) some oil in an old crock pot and the color was much darker than the store bought stuff.  It seemed to dry a lot faster than the un-boiled.  Do you think it "polymerized" or should I get it hotter?............................Lynn

[Mad Monk]

MM  or DP or both or others knowledgeable - would you please describe your method of "cooking" your BLO?  Does it require the rolling boil of the deep fat fryer or is the slow cooking of the second hand crock pot sufficient?

How long is turpentine "aged"?  Just some things I need to learn.
Thanks........................Lynn

Easiest first here.

The turpentine exposed to air will be good to use after 3 or 4 weeks.
A comment here.
When you use oxygenated turpentine some will remain trapped in the oil finish.  Where it will change to a resin.  If you use common mineral spirits some will remain trapped but not convert to a resin.
This is why Venice Turpentine was/is so highly recommended when it is necessary to add a solvent/dilluent to a boiled oil.


Boiling oil.
That is a misnomer.  You really can't actually get the oil to boil in the way we normally think of it as with water.
The evolution of bubbles during the oil cooking process is the result of the organic acid(s) in the oil breaking down the dryer metal compound and converting the metal to an oil-soluble linoleate.  Once the dryer metal compound is fully converted you will see no more bubbling.  You must also use something to constantly skim the surface of the oil while you are "cooking" it in a pot.  The stuff that forms a scum floating on the oil should be removed.

I used to use a white porcelain enamel pot for oil cooking.  Don't use a spatter ware pot.  The hot oil eats certain color spatter.  In the old oil plants they used copper pots if the batch size was not too large.  If cooked in iron pots the oil tends to turn brown and loose the red color.  Excessive cooking in iron pots also may create drying problems.

I cooked my oil out back.  A gallon porcelain enamel pot set up on bricks over a little charcoal fire.  There is of course always the danger of an oil fire when using an open charcoal fire.  I kept the lid handy and a stick to place it on the pot in the event the surface of the oil ignited.
You just use a low fire and heat it slowly.  Figure several hours on this.  Do not cover the pot while cooking.  Vapors build up under the lid and when you remove the lid you get instant fire, which is how they once made printing inks.  Uncovered is no problem.

With the dryer metal compound added in the oil and heating.  When you see bubbling that is the oil breaking down the dryer metal compound and being converted to the oil-soluble linoleate "metallic soap" in the oil.  Once you see that you back off on the fire a bit.  If you get carried away and overheat the oil it creates side reaction products that will actually prevent the finished oil from drying.

If you keep the heat low under the pot for a long time you will indeed polymerize the oil.  Making it more viscous.  The oil cooking/drying process is a classic diene reaction.  Almost the same as one would see in the manufacture of polyvinyl chloride resins and snythetic rubber production.

Work in small amounts.  My maximum batch size used to be 1 gallon batches out in the rear of the yard.  In my lab work I worked with pints.

Depending on what brand of oil you start with you can get a good batch and then again a bad batch.  Some commercial boiled oils were better than others for this work.  So buy only a pint to a quart of the commercial boiled oil as your starting point.  Twenty years ago when I was doing all of my set up work on this I found that there were two brands of commercial boiled oil that I simply could not get to work no matter what I did.

E. Ogre

[billd]

Mad Monk,   The two brands that you said wouldn't work for you, are they still one the market?   If so, could you tell us which brands.   I'm thinking my local hardware store sell Parks.

[Robert Wolfe]

We have had several great threads on boiling your own linseed oil over the years. Anyone care to pull it all together and put it the tutorials section?

Acer - where are you?

[LynnC]

Thank You again MM.
That oil I did in the crock pot did indeed thicken up alot.  I don't recall having to skim it though.  It turned out darker and thicker.  Probably needed to get it hotter to cook the impurities out and skim the crud off the top.  I have used some of that oil lately and had to thin it with turpentine as it had taken on a jelled consistency.  Seemed to dry pretty fast in the sun.............................Lynn

[Mad Monk]

Mad Monk,   The two brands that you said wouldn't work for you, are they still one the market?   If so, could you tell us which brands.   I'm thinking my local hardware store sell Parks.

Years ago we had a nearby hardware store before the big home centers took the business.  This hardware store sold Parks brand boiled oil.  I used it and it worked.  After that I could not find Parks and what I bought at the "box store" did not work.

If you haunt yard sales or farm sales keep your eyes open for old containers of boiled oil.  If the oil is a deep ruby red color you have good old lead based boiled oil.  I know a few builders who keep their eye out for this.  A gallon of 40's or 50's commercial boiled oil is a prized find and don't quibble price.

E. Ogre

[LynnC]

I bought what I'm using at an estate auction.  Archer pol-mer-ik BLO.  Looks like 50's advertising on the gallon can.  Sort of a dark golden color before cooking and dark reddish after.........................Lynn

[Mad Monk]

Thank You again MM.
That oil I did in the crock pot did indeed thicken up alot.  I don't recall having to skim it though.  It turned out darker and thicker.  Probably needed to get it hotter to cook the impurities out and skim the crud off the top.  I have used some of that oil lately and had to thin it with turpentine as it had taken on a jelled consistency.  Seemed to dry pretty fast in the sun.............................Lynn

The acxtual drying of the boiled oil in thin films is not a drying process that relates to any loss of liquid.  It is a polymerization process that requires the addition of oxygen to the film on the surface of the wood.  Individual molecules of the boiled oil are joined together by the addition of oxygen atoms to form long polymer chains with little cross linkages in a lead boiled oil.  Certain conditions may slow this drying process while other conditions speed it up.

Humidity.
A boiled oil prepared with lead as the dryer metal is not sensitive to variations in relative humidity.  Higher humidity does not slow the drying/polymerization process as is seen in managense or cobalt dryer based oils.
With manganese or cobalt driers once the R.H. goes above 50% you will see a slowing of the drying/polymerization process.  At about 80% R.H. the process almost comes to a complete halt.

Air flow.
Since the drying/polymerization process is an oxygen addition process you want some constant movement of air across the surface of the oil film to give a maximum amount of available oxygen at all times.

Temperature.
Basically, the warmer the surface the faster the drying/polymerization process.  The temperature during drying/polymerization may also Affect the properties of the "dry" film on the wood.  In PVC resin production the temperature during the polymerization process governs molecular weight in the final resin.  Higher reaction temperatures results in longer polymer chains which controls the physical properties of the resin.  In the production of PVC resins a test known as relative viscosity is used to judge polymer chain length.

Sun light.
The drying/polymerization rate is influenced by the presence of direct sunlight.  The UV light, in sunlight, acts to speed up the drying/polymerization process.  But understand that in a boiled oil film with pigmentation or UV adsorber the UV light serves to break the oil film down again.  Almost akin to a depolymerization reaction.

An example of this sunlight thing is seen in the Spring 1988 issue of The Museum Of The Fur Trade Quarterly.  "Fur Trade Oil Cloths."
A description of the first documented oil cloth "factory" set up in London in 1740.  Set up in lofts of buildings with plenty of windows facing the path of the sun.

E. Ogre

[Joe S]

When do you add the resins to the oil? Do the resins need to be heated to high temperatures, or is it sufficient just to have them in solution?

[Mad Monk]

When do you add the resins to the oil? Do the resins need to be heated to high temperatures, or is it sufficient just to have them in solution?

Which resins are we talking about here?

E. Ogre

[Joe S]

Resins to make varnish with.  Sorry I wasn’t clear about that.  When I have boiled oil in the past, it was to make varnish, not just straight BLO.

[Mad Monk]

Resins to make varnish with.  Sorry I wasn’t clear about that.  When I have boiled oil in the past, it was to make varnish, not just straight BLO.

That is going to depend on what type of resin you use.
I am assuming here that you will use one of the natural gum resins.
They used to make a lot of varnish with phenolic resins added but these resins are not normally available to anyone outside of the paint and varnish industry.

If you go with a natural resin you should do some digging on the Internet.  Some resins are directly soluble in warmed boiled oil while others are not.  Those that are not directly soluble must be "heat run" as they used to call it in the industry.

Take sandarac resin for instance.  The gum derived from the European Larch which also yields Venice turpentine.
This resin must be heat run before being mixed in with the oil.  The normal method is to take two pots.  One smaller than the other.  You use this as you would a double boiler but using sand between the two pots rather than water.  You want to spread the heat out evenly on the pot holding the resin.  Which the sand helps to do.  You also don't want to heat the inner pot's surface too hot or you scorch the resin.
After the sandarac resin melts you will reach a temperature where the resin begins to foam.  then you skim the foam from the semi-fluid resins.  Ditch the skimmed foam.  In another pot you would have heated the boiled oil being used to make the varnish.  You trickle the heated oil into the point holding the melted resin while gently stirring it.  If the oil is not hot enough the resin will solidify and not mix into the oil.  Once you have the required amount of oil in with the resin to continue to stir a bit.  While warm, but not hot, you may pour it into a suitable storage container.  If you use a glass bottle for storage you will neeed to cool the varnish down almost to room temperature before bottling.

In this resin "running" process you are in effect depolymerizing the resin to some extent besides driving off any "essential oil" in the resin.

If you buy the natural gum resin from an art supply store you must watch it.  Some are not actually the real resin but a substitute that mimics the real resin in most applications.  I ran into this with a copal resin solution from one art supply source.

When it comes to the use of natural gum resins in a varnish Eric K. has carried his work far beyond what I did.  I simply tried to duplicate the old traditional European "common varnish" made with boiled oil, sandarac resin, venice turpentine and a bit of gum mastic.  One source I looked at from the 1500's stated that this varnish was common on cross-bows.  Which had me mentally picturing some guy pulling the bow off the front of a cross-bow stock and figuring where the big deep groove would go.  I saw pictures of some very early firearms with stocks that looked very close to cross-bow stocks.

E. Ogre

[Stophel]

Lead carbonate is "flake white" or "white lead".  It was the common white pigment prior to titanium dioxide.  It is available from Kremer Pigmente/Sinopia.  www.sinopia.com   I bought a big plastic sack of the stuff.  Probably a half a gallon.  Cost me very little....ten bucks maybe.  I have enough lead carbonate to last me about four lifetimes.

To do oil alone...making "black oil" or "red oil" for use as a boiled linseed oil finish:

Put about two pints of good quality cold pressed linseed oil in your deep fat fryer thing.  It needs to be just at a very low rolling boil.  Just turning over.  It doesn't need to be any hotter than that.  Add about 1 tsp for every pint of oil (it ain't that critical).  You can also add the same amount of an umber pigment, which is also a drying agent.  The oil will turn dark reddish brown.  The smell will also change, unfortunately.    Now, I want my oil thick.  The longer you boil it, the thicker it will get.  Basically, when boiling, it is taking up oxygen (as I understand it), and it is "predrying".  I boiled my last batch of oil for an hour and a half.  DO NOT leave it unattended.  DO NOT let it get too hot.  DO NOT do this without the properly fitting lid for your fryer and a fire extinguisher at hand. 

The resultant concoction is pretty durn thick.   When through boiling, let it cool a while (but it needs to still be warm enough to pour out of the cooker), and then pour it into glass jars.  It will be so thick, that you will have to use a good amount of turpentine to use it.  (Getting it the thickness you want is a lot of trial and error.  At intervals, dip some out with a stick, let it cool, and see how thick or thin it is.) It dries fast, and I can do a good boiled linseed oil finish in less than a week, given good weather and sunshine.

For varnish, I can't have it that thick.  I've tried, it's just not workable.  It has to be thinned heavily with turpentine (in fact, I end up with more turpentine than varnish), it gets tacky immediately, I can't smooth it out with my hands, and it doesn't level.  So, I have to leave it much thinner.

My last batch of varnish I boiled for just a half hour.  I added (I think...) 6oz. of rosin and 2oz. of Mastic.  These two resins melt and fuse readily in the hot oil.  Benzoine will work too, but it is absolutely FILTHY, and I haven't come up with a decent means to filter it out.  The varnish is still relatively thin and fluid. Not much thicker than the oil was originally.  It flows wonderfully, and I can smooth it out with my hands, and I don't have to worry about trying to smooth it off after it dries, which is a bad thing all the way around.  It does not dry nearly as quickly as my thick black oil.  It must be put on THIN.  This cannot be emphasized enough.  T-H-I-N.  After the grain is filled with linseed oil or shellac, and the surface is prepared, rub on a coat of the varnish very thin with your hands, and set it out in the sun to dry.  I have found that with what I am using now, it will sort of dry to the touch in a day of good sunlight.  It needs several days of solid sunlight before it is really thoroughly dry, and will no longer fingerprint.  DO NOT get impatient.  It absolutely MUST dry thoroughly before recoating, or it will never dry completely.  if each coat takes a week, it takes a week.  If each coat takes two weeks, it takes two weeks.  Repeat as necessary.

I MAY be able to reduce the drying time by adding more lead carbonate...I don't know yet, but this is where I stand at the moment.  As I understand it, old oils/varnishes have been tested and they show VERY high lead/lead carbonate levels, so I think they probably really poured it in.

[Mad Monk]

Chris,

Adding lead beyond a certain point does not improve the drying time.

One varnish manufacturer studied this early in the 1900's.  The best drying time came with a half a part of lead in the oil and a half a part of manganese.

How much lead will be incorporated into the oil as a dryer metal will depend on the acid value of the oil.  There is a limit as to how much you can get incorporated into the oil.

In varnish manufacturing in the late 19th century and early 20th century you did not see rosin being incorporated into the oil to make a varnish.  You would sometimes see limed rosin being used to get the pH of the oil up to something more neutral.

Umber pigment.
This goes back to when artists in the Europe switched from egg white to linseed oil as their painting medium.  They found that when they added umber or burnt umber to the oil it dried a lot faster.
Umber pigment, from the Umber region of Italy, had a manganese dioxide content of around 8 to 10%.  This is where the idea for manganese dryer came in later once the linoleum factories started up around the time of the Civil War.  If the umber pigment is one of the "synthetic" iron oxide pigments it will most likely not have any manganese in it.