Author Topic: lead carbonate  (Read 16273 times)

billd

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Re: lead carbonate
« Reply #25 on: March 02, 2009, 06:12:59 AM »
Wow,  what an informative thread this has become.  Thank you Mad Monk.  But to get back to my original question and verify.  Lead carbonate is the white crystal like residue that forms on the outside of lead from oxidation.  This is added at the rate of .5 to 1.0% by weight to the linseed oil before boiling it. 

Is this correct?

Bill

Offline Stophel

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Re: lead carbonate
« Reply #26 on: March 02, 2009, 06:36:45 AM »
No, that is lead oxide.  Though apparently, that works as well.

Supposedly "red lead" is an excellent drier (I don't know what that is, exactly), but it seems to currently be hard to come by.
When a reenactor says "They didn't write everything down"   what that really means is: "I'm too lazy to look for documentation."

Greg Field

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Re: lead carbonate
« Reply #27 on: March 02, 2009, 06:39:23 AM »
On most forums I am a regular on, I am the crazy bastard who knows all this kind of stuff. It's both amazing and refreshing to be the one on the receiving end, here. Thank-you all!

billd

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Re: lead carbonate
« Reply #28 on: March 02, 2009, 06:44:30 AM »
Thanks Stophel,  A chemist I ain't.   Eric's article describes how to make this using vinager so I thought it was lead carbonate.   ???   Check out the following link. The description is why I thought what I did.

http://naturalpigments.com/detail.asp?PRODUCT_ID=475-11S

They have red lead too.

Bill
« Last Edit: March 02, 2009, 06:45:17 AM by billd »

Offline rick landes

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Re: lead carbonate
« Reply #29 on: March 02, 2009, 05:03:34 PM »
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
I had no clue if lead carbonate was a solid. I thought mixed into a finish it was a liquid...that's why I am more of a sociologist and not a chemist :)
Hope that info did not mess something up :-[
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Offline Mad Monk

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Re: lead carbonate
« Reply #30 on: March 02, 2009, 05:25:31 PM »
Thanks Stophel,  A chemist I ain't.   Eric's article describes how to make this using vinager so I thought it was lead carbonate.   ???   Check out the following link. The description is why I thought what I did.

http://naturalpigments.com/detail.asp?PRODUCT_ID=475-11S

They have red lead too.

Bill

The manufacture of lead acetate, or sugar of lead, goes back to the ancient Greeks.  Written about by Pliny, the Elder, in 50 A.D. in Rome along with copper acetate.
The standard method was to take a crock and add sour wine vinegar in the bottom of the crock.  A piece of wood would go in next.  Then a lead plate or disk.  The lead plate sat on top of the wood so that only the vinegar fumes would contact the lead.  These crocks were covered and then stacked in racks which were then covered with manure.  The manure providing heat to speed the process up.  The acetic acid given off by the vinegar is highly reactive with the lead (or copper) in the vapor form.  Far faster than liquid contact.
After a period of time the lead acetate was scraped off the plates after removing them from the crock.

If the lead acetate (sugar of lead) is exposed to damp air for any length of time it would convert over to lead carbonate.  With copper and lead the carbonate form is the "environmentaly stable" form.

I dug into how it was made long ago.  These lead compounds were pulled out of the paint, plastics and rubber industry some years ago.  It will not be long before you simply cannot buy lead pigments.
When I started the experimental work in the lab the engineering staff went bonkers.  We were not supposed to have any lead compounds in the plant.  So "production" was shifted to my basement.

E. Ogre

billd

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Re: lead carbonate
« Reply #31 on: March 02, 2009, 05:29:39 PM »
Mad Monk,   Is the link I posted the correct stuff?

Bill

Joe S

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Re: lead carbonate
« Reply #32 on: March 02, 2009, 07:18:09 PM »
Gum benzoin is easy to deal with.  It is very soluble in alcohol. All you need to do is grind it to a powder (or hammer it, which is how I did it because my wife won’t let me borrow her mortar and pestle), then dissolve it in alcohol.  Then you can easily strain out the sticks and dirt and pour the clean solution into cold BLO.  Next, heat the oil to drive off the alcohol.  Alcohol boils at about 200 F.

Gum rosin can be handled the same way.  It is soluble in turpentine and alcohol.

I made a batch of varnish last summer using this method.  I heated it to about 240 degrees so that the temperature was above the melt point of the rosin and gum benzoin.  I don’t know if this is really necessary or not.  It could be sufficient just to have them in solution, but since all the recipes I’ve seen involve melting the resins, I thought that would be the safest way to go.

I ended up with a nice low gloss varnish that seems to be durable.  I put a couple of good dents in my gun this fall,, and the varnish didn’t crack or chip.

Offline Mad Monk

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Re: lead carbonate
« Reply #33 on: March 02, 2009, 07:59:02 PM »
Mad Monk,   Is the link I posted the correct stuff?

Bill

That is what you want.

Note:  Watch any dust.  You don't want to inhale any of the dust from that.  If you get it on your hands you should wash your hands well.  It will not go in through the skin.  Must be inhaled/ingested to get into the blood.

What you are looking at there is known as tribasic lead.  Once commonly used in tire rubber, PVC compounds and paints.  Used a good bit of it as pigment.

I always used respiratory protection and gloves.  Never had any blood lead level problems though we handled tons of that stuff.

E. Ogre

billd

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Re: lead carbonate
« Reply #34 on: March 02, 2009, 08:06:04 PM »
Mad Monk,   Is the link I posted the correct stuff?

Bill

That is what you want.

Note:  Watch any dust.  You don't want to inhale any of the dust from that.  If you get it on your hands you should wash your hands well.  It will not go in through the skin.  Must be inhaled/ingested to get into the blood.

What you are looking at there is known as tribasic lead.  Once commonly used in tire rubber, PVC compounds and paints.  Used a good bit of it as pigment.

I always used respiratory protection and gloves.  Never had any blood lead level problems though we handled tons of that stuff.

E. Ogre



Thanks Bill,    I know the dangers.  I have no children or grandchildren around either and we're too old for more.  Thanks for the warnings.

Bill D.

Offline Stophel

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Re: lead carbonate
« Reply #35 on: March 02, 2009, 09:18:49 PM »
Gum benzoin is easy to deal with.  It is very soluble in alcohol. All you need to do is grind it to a powder (or hammer it, which is how I did it because my wife won’t let me borrow her mortar and pestle), then dissolve it in alcohol.  Then you can easily strain out the sticks and dirt and pour the clean solution into cold BLO.  Next, heat the oil to drive off the alcohol.  Alcohol boils at about 200 F.

Gum rosin can be handled the same way.  It is soluble in turpentine and alcohol.

I made a batch of varnish last summer using this method.  I heated it to about 240 degrees so that the temperature was above the melt point of the rosin and gum benzoin.  I don’t know if this is really necessary or not.  It could be sufficient just to have them in solution, but since all the recipes I’ve seen involve melting the resins, I thought that would be the safest way to go.

I ended up with a nice low gloss varnish that seems to be durable.  I put a couple of good dents in my gun this fall,, and the varnish didn’t crack or chip.


I ALMOST did this very thing a few months ago, but was scared of heating alcohol.  I dissolved a quantity of benzoine in alcohol, filtered the sticks and bugs out of it and poured it into aluminum cake pans to dry.   EVENTUALLY it dried out, but I had a surprising amount of loss (by weight) of the benzoine, which is alright, I guess, since benzoine is a lot cheaper than mastic!! I then put the dry benzoine in the oil.  It was a lot of trouble this way.  I had to wait weeks for the benzoine to fully dry (or nearly fully dry...)

My rosin has all been quite clean, and it dissolves readily into the hot oil, as does mastic, which is why I have just stuck with those two. They were commonly used at the time for "plain brown varnishes".  Mastic ain't cheap, though.

Actually, some of the varnish I am currently using is some I did with rosin and the benzoine.  I'm not really convinced the type of resin used makes a whole lot of difference, other than rosin is supposed to eventually get brittle.  Mastic is considered one of the better resins, and it is known as being quite elastic (hence the name...you can chew mastic.  Chewing gum is, or at least used to be, made from mastic).

I'm not a chemist, I'm an alchemist.  ;)
When a reenactor says "They didn't write everything down"   what that really means is: "I'm too lazy to look for documentation."

Offline Stophel

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Re: lead carbonate
« Reply #36 on: March 02, 2009, 09:21:59 PM »
Thanks Stophel,  A chemist I ain't.   Eric's article describes how to make this using vinager so I thought it was lead carbonate.   ???   Check out the following link. The description is why I thought what I did.

http://naturalpigments.com/detail.asp?PRODUCT_ID=475-11S

They have red lead too.

Bill

Thanks.  I want to try red lead.  A couple of years ago, when I first started all this, I got my white lead from Kremer, who said that, at the time, red lead was hard to come by.  They could get it from time to time, and it wasn't cheap.  I'll check this out.  Probably won't matter which one I use, but I like being different.

Alum is often mentioned in old varnish recipies, and I think Greywolf has experimented using alum.
When a reenactor says "They didn't write everything down"   what that really means is: "I'm too lazy to look for documentation."

Offline Stophel

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Re: lead carbonate
« Reply #37 on: March 02, 2009, 09:38:37 PM »
By the way, here's a good source of oil, resins, shellac, and other things

www.woodfinishingenterprises.com

I've been using their "Varnish makers oil".  I also have some mastic from them and aged turpentine (which is golden-red and quite thick).  I've been meaning to make myself some "oxygenated turpentine"...I figure I can do it cheaply with a fish bubbler blowing air through a loosely covered container.  After six months  or so...
When a reenactor says "They didn't write everything down"   what that really means is: "I'm too lazy to look for documentation."

Joe S

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Re: lead carbonate
« Reply #38 on: March 02, 2009, 09:48:38 PM »
 
Quote
I ALMOST did this very thing a few months ago, but was scared of heating alcohol.

Just pour the alcohol/resin solution into cold oil, and then heat it slowly.  As you reach the boiling point of the alcohol, you’ll see some bubbles.   After a while, it will quit bubbling.  That’s all that happens. This is a very safe procedure.  Much safer than say, boiling oil over an open flame.  Not that anybody around here is dumb enough to do that…..

« Last Edit: March 02, 2009, 09:50:55 PM by Joe S »